#StopBurningStuff by 2030 or sooner

[grantmeaname]

Lol yeah, I will be sure to burn my mustachian card before writing the check. Just too too many projects up in the air right now to add one more.

Do you mean like an HRV/ERV? I saw they're required for new construction in Canada but haven't seen much about them stateside.

[tygertygertyger]

My partner keeps talking about some air exchange thing. (I am not well versed, I just hear about it a lot.) He'd bought a portable CO2 monitor during the pandemic as a gauge to check how well ventilated our house and other locations are. There are studies showing that higher CO2 levels can impair your cognitive function. Turns out our house just slowly builds in CO2 over the course of a day during the summer. After we installed a whole house fan in our attic, turning it on for 5-10 minutes at a time with the windows cracked really helped with that. Of course, our friends' drafty old houses do better naturally!

Weirdly, once we turned the furnace on, our monitor showed CO2 levels were sustained reasonably lower. We thought our furnace must be doing a good job exchanging air with outside air... until my partner started doing air sealing in the attic. He noticed that the old insulation near the gaps up there showed a lot of black, like air was just rising up into the attic. So with air sealing, we're back to higher levels in the house again. But, one problem at a time. Adding insulation next to further seal us into our tomb (but keep us much warmer).

[AlanStache]

Lol yeah, I will be sure to burn my mustachian card before writing the check. Just too too many projects up in the air right now to add one more.

Do you mean like an HRV/ERV? I saw they're required for new construction in Canada but haven't seen much about them stateside.

No you need to sell the mustacian card on craigslist :-)

Not sure of the names, just heard about such things existing but knew I would not buy one so did not look into them.  Current home has some electronic air zapper-filter thing that I think was broken when I bought so I just use old school filters and take drugs to reduce the symptoms of my allergies. 

Dont think I want to know what my daily indoor CO2 levels are.

[NorCal]

My partner keeps talking about some air exchange thing. (I am not well versed, I just hear about it a lot.) He'd bought a portable CO2 monitor during the pandemic as a gauge to check how well ventilated our house and other locations are. There are studies showing that higher CO2 levels can impair your cognitive function. Turns out our house just slowly builds in CO2 over the course of a day during the summer. After we installed a whole house fan in our attic, turning it on for 5-10 minutes at a time with the windows cracked really helped with that. Of course, our friends' drafty old houses do better naturally!

Weirdly, once we turned the furnace on, our monitor showed CO2 levels were sustained reasonably lower. We thought our furnace must be doing a good job exchanging air with outside air... until my partner started doing air sealing in the attic. He noticed that the old insulation near the gaps up there showed a lot of black, like air was just rising up into the attic. So with air sealing, we're back to higher levels in the house again. But, one problem at a time. Adding insulation next to further seal us into our tomb (but keep us much warmer).

It sounds like he's talking about an Energy Recovery Ventilator (ERV).  We had a quote for one of those with the heat-pump, but didn't end up purchasing it.  They quoted $3k for it as part of the larger project.

It is pricey, but they would improve the air quality in your home. 

I also have an air quality monitor, and simply opening windows and getting fresh air in makes a big difference.  But that only works when the outside temperature is reasonable.  Which works for us in the summer but not the winter.

[grantmeaname]

A heartbreaking day for the save the planet squad.

I got my geothermal quote and it came in more expensive than expected, and when I reran the installer's savings numbers with less unfair inputs, my best quote had a 1.4% ROI.

I'm in a pickle. I don't want to buy a new roof to put up a small solar array - just the roof plus a baby solar system sized for my current electric load is a 2.9% ROI. I don't want to put up a big solar array if I need to accept a 1.4% ROI geothermal project to electrify that load. The total project of roof, geothermal, and heat pump water heater together has a 1.8% ROI (or 1.9% if adding an EV).

So I guess I pay the mortgage, ride my bike more, and turn the thermostat lower for now.

[Weisass]

A heartbreaking day for the save the planet squad.

I got my geothermal quote and it came in more expensive than expected, and when I reran the installer's savings numbers with less unfair inputs, my best quote had a 1.4% ROI.

I'm in a pickle. I don't want to buy a new roof to put up a small solar array - just the roof plus a baby solar system sized for my current electric load is a 2.9% ROI. I don't want to put up a big solar array if I need to accept a 1.4% ROI geothermal project to electrify that load. The total project of roof, geothermal, and heat pump water heater together has a 1.8% ROI (or 1.9% if adding an EV).

So I guess I pay the mortgage, ride my bike more, and turn the thermostat lower for now.

What is going into your ROI figure?

[grantmeaname]

For geothermal the return is annual running cost savings below the annual running costs of my current system (2014-2018, reasonably efficient), which is variable costs of the appropriate fuel plus $450/year for giving up natural gas service and avoiding its fixed charges. The return improves somewhat but is still very poor in absolute terms if I go back to using dirty fossil electricity, but on the other hand there is no net benefit to the planet - indeed a net cost - if I go that way.
I have a working system now so the investment is the full cost of the upgrade, net of the 30% tax credit.

For solar the return is just total estimated kWh of use (current use plus geothermal heat/hot water for needs currently served by gas) times the rate I currently pay for green power ($0.15/kWh). The investment is a metal standing seam roof ($22k) plus 70% of the cost of the solar system ($1.40 per watt from Unbound Solar/Solar Wholesale, though not exactly variable if I go much bigger or smaller), and the cost of the roof would come out of that denominator if or when it needs replaced for its own sake.

Edit:
It feels like the only reasonable way to look at things is with the whole project put together - geothermal to electrify my big heating/cooling load, arguably an EV to electrify transportation too, solar to power it, roof to hold the solar. Any subset of the project is not as appealing. It will get more appealing the day my furnace, AC, or roof dies

Could you take the metal roof out? Sure, though it's not totally intellectually honest IMO. If the roof needs replaced of its own accord, I'll very happily do it and accept the now-more-appealing project ROI.
Could you just buy a small solar system proportional to your usage today for lighting and appliances, then expand it later? Yes, but then there are fewer kWh over which to amortize the cost of the roof, and the $/kW will go up by doing the solar work in two pieces instead of one. I've thought about this path but I'm not totally sold on it.
Can you buy geothermal without buying solar? Yes, but the only way to make the math really work is to use dirty power so I can fail to accomplish my environmental goals while I fail to accomplish my financial goals. Yuck.

[NorCal]

For geothermal the return is annual running cost savings below the annual running costs of my current system (2014-2018, reasonably efficient), which is variable costs of the appropriate fuel plus $450/year for giving up natural gas service and avoiding its fixed charges. The return improves somewhat but is still very poor in absolute terms if I go back to using dirty fossil electricity, but on the other hand there is no net benefit to the planet - indeed a net cost - if I go that way.
I have a working system now so the investment is the full cost of the upgrade, net of the 30% tax credit.

For solar the return is just total estimated kWh of use (current use plus geothermal heat/hot water for needs currently served by gas) times the rate I currently pay for green power ($0.15/kWh). The investment is a metal standing seam roof ($22k) plus 70% of the cost of the solar system ($1.40 per watt from Unbound Solar/Solar Wholesale, though not exactly variable if I go much bigger or smaller), and the cost of the roof would come out of that denominator if or when it needs replaced for its own sake.

Edit:
It feels like the only reasonable way to look at things is with the whole project put together - geothermal to electrify my big heating/cooling load, arguably an EV to electrify transportation too, solar to power it, roof to hold the solar. Any subset of the project is not as appealing. It will get more appealing the day my furnace, AC, or roof dies

Could you take the metal roof out? Sure, though it's not totally intellectually honest IMO. If the roof needs replaced of its own accord, I'll very happily do it and accept the now-more-appealing project ROI.
Could you just buy a small solar system proportional to your usage today for lighting and appliances, then expand it later? Yes, but then there are fewer kWh over which to amortize the cost of the roof, and the $/kW will go up by doing the solar work in two pieces instead of one. I've thought about this path but I'm not totally sold on it.
Can you buy geothermal without buying solar? Yes, but the only way to make the math really work is to use dirty power so I can fail to accomplish my environmental goals while I fail to accomplish my financial goals. Yuck.

Keep in mind that the return you're calculating is the real return and not the nominal return.  To make it apples-to-apples with your investing strategy, you should either adjust your efficiency return upwards to count for inflation savings, or adjust your nominal expected investment returns downwards as a point of comparison.  A common number is using 4% real returns for investing with 7% nominal returns. 

It still doesn't look great, but it doesn't look as horrible.  Also keep in mind that the two biggest threats to a long term financial plan are longevity risk and inflation risk.  There's a lot to be said for cutting your inflation risk as part of your overall portfolio strategy.  But I admit I'm partially saying this to justify my own financial decisions in this realm.

In my case, I just made this part of my FI goals.  I said I would save $X and eliminate as much of my emissions as I reasonable could before pulling the FI trigger.  In the grand scheme of things, getting my energy footprint close to zero was a rounding error.  It might move an FI date out a few months, but it wasn't major, and it partly depended on energy price inflation.  Calculate how much this moves your FI date by and see if that's something you're willing to live with.

[LD_TAndK]

I considered myself part of the "save the planet squad". I realize that all my pro environmental decisions were also fattening my wallet or making me healthier or providing some other benefit. I've never done something that didn't also benefit me.

Anyways I've been feeling an urgency recently to this whole stop burning stuff thing and think it's our responsibility to make pro-environment moves, with poor ROI, or outright losing money.

[nereo]

I considered myself part of the "save the planet squad". I realize that all my pro environmental decisions were also fattening my wallet or making me healthier or providing some other benefit. I've never done something that didn't also benefit me.

Anyways I've been feeling an urgency recently to this whole stop burning stuff thing and think it's our responsibility to make pro-environment moves, with poor ROI, or outright losing money.

Welcome to the club!

[rockeTree]

Yeah. This has a positive ROI and it sounds like it would not be a huge strain on you to make the investment, thereby advancing the tech, cutting carbon now, and no doubt improving your home. To me that's a yes, as a person living in and surrounded by the most environmentally destructive civilization going. There are things I can't do, or can't do without losing my ability to support my family and be part of my community - but I at least want to do the things I can do pretty easily!

How do feed in tariffs work where you are? Any sense in oversizing the solar, which you say doesn't add much up front cost, even if you are not immediately electrifying your heating load? It's clean energy on the grid displacing dirtier energy in most of the US at least.

[RWD]

The fact that there is a financial benefit at all to this stuff is just a bonus for me. I'm after the improvements to quality of life and contributing to overall electrification. Certainly starting with the stuff that has the biggest ROI makes sense. But people do kitchen remodels that have an ROI of 0%. Not everything has to be ROI driven.

I do think at a certain financial stage of life that we have an obligation to make environmentally conscious choices, even if they do not make the most financial sense. Sure, when I was just starting out and had student loan debt, was underwater on our house, and no investments there was no way I was going to drop $50k on solar panels and other various updates. But now that we have minimal low-interest debt and a million dollar portfolio I would feel like such the miser to declare the ROI to be too low.

[grantmeaname]

How do feed in tariffs work where you are? Any sense in oversizing the solar, which you say doesn't add much up front cost, even if you are not immediately electrifying your heating load?

I am in a purple state captured by a deep red state government, so the terms are very poor. I can feed in up to 120% of my actual usage, and anything in excess of that is not paid for at all. I think the geothermal load is sized similarly to all of my current consumption (so the right size system is ~200% of what I use now). Further, for what I do feed in, I am net metered only on the generation charge and not the distribution charge.

It's clean energy on the grid displacing dirtier energy in most of the US at least.

Yes and no. The unstable contribution of renewables makes more need for dispatchable natural gas "peaker" utility plants. Still better than goal, but worse than nuclear, hydro, or even steady-as-she-goes natural gas base load plants.

[nereo]

I do think at a certain financial stage of life that we have an obligation to make environmentally conscious choices, even if they do not make the most financial sense. Sure, when I was just starting out and had student loan debt, was underwater on our house, and no investments there was no way I was going to drop $50k on solar panels and other various updates. But now that we have minimal low-interest debt and a million dollar portfolio I would feel like such the miser to declare the ROI to be too low.

This is similar to where we have landed as well. For us, climate change and our impact on the planet are primary concerns, and since we've made the transition from "broke, indebted grad students" to "reasonably well paid professionals with ample savings" it seems important that we view all of our actions on a multi-decadal timescale. Our home and vehicles are the most logical places to focus on, since they represent the bulk of our emissions and (in the case of our home) will continue to exist for potentially a century or more.

As an example, we are going to be replacing the siding in the next year.  We could go the cheap route (vinyl siding) for about $7k or locally sourced, sustainable, biodegradable cedar for $8.5k, OR we could use the opportunity to add exterior insulation (likely mineral wool) plus sustainable cedar shake for around $12k. The most expensive option is "just" $5k over the cheapest, and results in a home that will be far more comfortable, quieter and use less energy to heat and cool for the next half-century at a minimum.  From a strictly ROI perspective it's probably in the 10-12 year zone, but just having a lighter footprint on the planet is also of value, and matters about as much as the ROI.

[grantmeaname]

think it's our responsibility to make pro-environment moves, with poor ROI, or outright losing money.

sounds like it would not be a huge strain on you

now that we have minimal low-interest debt and a million dollar portfolio I would feel like such the miser to declare the ROI to be too low.

It's unfair to reach into someone else's pocketbook and spending and say this should be an easy decision. This is 20-25% of my investment portfolio or 15-20% of my entire adult lifetime spending. This is a massive decision and it would be reasonable to pause savings or divert a big chunk of net worth to fund it if the ROI was there. If it's not there, then it's much more like a consumption decision - do I want to spend an unbelievable pile of cash today for a moderate impact on my already modest ecological footprint, and throw away a reasonably efficient and sound roof, furnace, hot water heater, and air conditioner while I'm at it?

Said another way, when a ton of carbon costs ~$100 in the minority of the world where it's priced and I'm putting out 10-14 tons of carbon a year heating/cooling/driving, it's arguably ridiculous to tie up $80-100k today for an annual annuity return of $1000 and $1400 of carbon savings. If the roof needs to go anyway, or the furnace goes anyway, and the financial case is there too, it's a decision I'd happily make in a second.

Edit: I guess the last thing I'll add is that last summer and fall I read two books that were very influential on my thinking here,  Less is More: How Degrowth Will Save the World and Plenitude. We don't just have a CO2 crisis or greenhouse gas crisis, we have a total stuff crisis. Too much mining, too much developed land, too much freshwater usage, too much pressure on the biosphere. The material intensity of our economy is inexorably increasing and has been relatively tightly linked with GDP growth the whole way. The problem with measuring a project solely on CO2 reduction is that something that uses a huge quantity of other resources can grade out better than it should - this is what Syonyk is talking about when he suggests using fossil fuels for a couple hours a year of outage usage rather than $10k of lithium batteries. The solution? erm, idk, not sure I've seen a good rigorous way to think about this, but throwing away four perfectly good mechanical systems to improve one metric smells bad from this perspective.

[grantmeaname]

From a strictly ROI perspective it's probably in the 10-12 year zone, but just having a lighter footprint on the planet is also of value, and matters about as much as the ROI.

I would be ridiculously thrilled to see a 12 year ROI on any of this. I'd pull the trigger today if it was even 25 years, because then it beats the 4% rule and is accretive compared to just sticking it all in VTSAX and retiring. But what I'm looking at an ROI in the range of the entire lifetime of the components replaced - like a 60 year ROI on geothermal or 40 years on geo+solar+roof. The case for both the investment and its environmental benefits gets so weak then.

[nereo]

From a strictly ROI perspective it's probably in the 10-12 year zone, but just having a lighter footprint on the planet is also of value, and matters about as much as the ROI.

I would be ridiculously thrilled to see a 12 year ROI on any of this. I'd pull the trigger today if it was even 25 years, because then it beats the 4% rule and is accretive compared to just sticking it all in VTSAX and retiring. But what I'm looking at an ROI in the range of the entire lifetime of the components replaced - like a 60 year ROI on geothermal or 40 years on geo+solar+roof. The case for both the investment and its environmental benefits gets so weak then.

Thankfully (or not?) we are still at a point where these 10-20 year ROIs (or less) are pretty much everywhere for our particular situation.
Going back to the cladding + exterior insulation piece, it works for us because i) we have to replace the siding anyway and ii) we can pay for it without resorting to 7%+ financing.  If the siding wasn't coming off anyway it would still be $12k, which would have a ROI of many decades.
We're in a similar spot with our windows in two rooms - single pane with broken glass and in very poor shape.  We have no choice but replacement, BUT ... the difference between replacing them with the cheapest to-code vinyl and the triple-pane casement equivalent is around $400 more per unit for our windows, and installation costs barely change. Harder to calculate the ROI (i've tried several different ways) but looks like in the 10-15 years for going with the more expensive, nicer, locally crafted option.  But if what we had was a functional double-pane window the numbers would look way, way less favorable, because we'd be spending over $1k per window.

[grantmeaname]

It seems like the ROI on the upgrade from a dirty replacement to a green one is almost always there. There are few projects so good that the ROI is there even when the existing systems work (air sealing, attic insulation) and we're definitely doing every one of those that we can find.

[rockeTree]

think it's our responsibility to make pro-environment moves, with poor ROI, or outright losing money.

sounds like it would not be a huge strain on you

now that we have minimal low-interest debt and a million dollar portfolio I would feel like such the miser to declare the ROI to be too low.

It's unfair to reach into someone else's pocketbook and spending and say this should be an easy decision. This is 20-25% of my investment portfolio or 15-20% of my entire adult lifetime spending. This is a massive decision and it would be reasonable to pause savings or divert a big chunk of net worth to fund it if the ROI was there. If it's not there, then it's much more like a consumption decision - do I want to spend an unbelievable pile of cash today for a moderate impact on my already modest ecological footprint, and throw away a reasonably efficient and sound roof, furnace, hot water heater, and air conditioner while I'm at it?

Said another way, when a ton of carbon costs ~$100 in the minority of the world where it's priced and I'm putting out 10-14 tons of carbon a year heating/cooling/driving, it's arguably ridiculous to tie up $80-100k today for an annual annuity return of $1000 and $1400 of carbon savings. If the roof needs to go anyway, or the furnace goes anyway, and the financial case is there too, it's a decision I'd happily make in a second.

Edit: I guess the last thing I'll add is that last summer and fall I read two books that were very influential on my thinking here,  Less is More: How Degrowth Will Save the World and Plenitude. We don't just have a CO2 crisis or greenhouse gas crisis, we have a total stuff crisis. Too much mining, too much developed land, too much freshwater usage, too much pressure on the biosphere. The material intensity of our economy is inexorably increasing and has been relatively tightly linked with GDP growth the whole way. The problem with measuring a project solely on CO2 reduction is that something that uses a huge quantity of other resources can grade out better than it should - this is what Syonyk is talking about when he suggests using fossil fuels for a couple hours a year of outage usage rather than $10k of lithium batteries. The solution? erm, idk, not sure I've seen a good rigorous way to think about this, but throwing away four perfectly good mechanical systems to improve one metric smells bad from this perspective.

That's fair. I didn't take all that from your earlier post, more of an "oh well doesn't pencil out as a great investment so no dice", but I could have read more carefully and I apologize. I didn't realize it was a big of a part of your total plan as it is, or that all your existing systems were in good shape.

We do have a "stuff" problem and I think it came up earlier on this thread - if you reuse/give away the old system, is it serving someone whose needs would not be met? Displacing a new efficient unit someone would otherwise buy? Replacing an even older and crummier one? Should I get an electric car and all its embedded materials if I drive so little the environmental impact of reduced emissions takes 30 years to make up for the impacts of its production? As you say, not easy answers when you get to the marginal decisions on some of these.

[grantmeaname]

That's fair. I didn't take all that from your earlier post, more of an "oh well doesn't pencil out as a great investment so no dice"

I hope that wasn't the impression I gave! I would love to do all these projects. If anything my attitude now is not-so-secretly hoping the furnace/roof will go so the math makes sense! These will definitely be upgrades I make as each component reaches the end of the lifespan. If the last gas furnace were to go into service today and it was all geothermal from here on out that would still be a stupendous outcome from my point of view... I'm just sad that I was primed to believe that they were worth it even as mid-life upgrades and when I ran the math a little more critically that assertion isn't close to true.

We do have a "stuff" problem and I think it came up earlier on this thread - if you reuse/give away the old system, is it serving someone whose needs would not be met? Displacing a new efficient unit someone would otherwise buy? Replacing an even older and crummier one? Should I get an electric car and all its embedded materials if I drive so little the environmental impact of reduced emissions takes 30 years to make up for the impacts of its production? As you say, not easy answers when you get to the marginal decisions on some of these.

Very well said. I think the Tesla Model X and F150 Lightning are obscene, but as someone who wants less CO2 out into the world, I'm thrilled to keep hypermiling a Honda Fit 7k miles a year while somebody who's between an Escalade and a Model X chooses the X for their 15k. I'll tread lightly with old dirty tech until there is any case to be made for the new stuff at even my reduced usage.

[rockeTree]

Yeah if my own aging Fit dies the decision would be between no replacement/cargo ebike and shed purchase and an electric replacement - I will not buy another ICE. But the car adds a lot of convenience to life and I would spend a good bit more on rideshares etc than I do on maintenance, so keeping it makes sense but buying an all electric car to mostly just sit does not. I work to use it less. This also means that I get closer to the time when the avoided emissions by biking instead make up for the carbon footprint of having my existing ebike made and shipped to me. Not there yet and I find myself wondering how many ebikes ever get there.

[Weisass]

Yeah if my own aging Fit dies the decision would be between no replacement/cargo ebike and shed purchase and an electric replacement - I will not buy another ICE. But the car adds a lot of convenience to life and I would spend a good bit more on rideshares etc than I do on maintenance, so keeping it makes sense but buying an all electric car to mostly just sit does not. I work to use it less. This also means that I get closer to the time when the avoided emissions by biking instead make up for the carbon footprint of having my existing ebike made and shipped to me. Not there yet and I find myself wondering how many ebikes ever get there.

I never thought about the carbon footprint of my ebike…. I bought the floor model from my local bike shop, and have put a thousand miles on it over 22 months…. How would I go about figuring out the carbon footprint for that?

[grantmeaname]

How many batter charges is that, how many kWh is that, and what is your state's grid power made out of?

Plus the embodied energy of making the bike itself, probably googleable or you could take an EV's footprint times their relative weights

[rockeTree]

Hmm I looked up some life cycle analyses on the production and shipping of a battery powered bike from China to the east coast, and the carbon gains per avoided gallon of gas, plugged in the mileage of my car, rounded and hand waved and figured by 1200 miles I was confident the embodied energy etc had been made up for by reduced gas and all subsequent miles are net gains. I feel like at some point I looked up the carbon intensity of PJM’s mix, maybe to decide which end of a range of some sort to use. I can try to find the paper again if you want to play with it yourself!

[rockeTree]

I am not finding the analysis I remember using but there are lots of ways to back of the envelope it.  A quick and dirty approach might be to use the Rad folks emissions analysis for ride vs drive https://www.radpowerbikes.com/blogs/the-scenic-route/electric-bike-emissions-calculator

And see how many miles it takes to get to the embodied CO2 in the bike.  You're looking for a ballpark here; no need to go into the time of day you charge your bike or the amount you pedal vs let the motor work (or the extension of the life of some but not all car parts due to lowered mileage) - for me I just wanted to say "I am using this instead of driving my existing car, which we will take as given. When has it covered its production and thus net reduced my emissions?"

The good people at BOSCH say production/transport/disposal of the bike itself is 300kg CO2-eq https://www.bosch-ebike.com/en/help-center/what-is-the-co2-footprint-of-an-ebike-187252   At Rad's "a net total of about 400 grams of CO2 for every car replacement mile" you get 750 miles before you come out ahead on the bike - lower than what I recall from my earlier guesstimate but Rad and BOSCH of course have their own incentives and one study may be older or based on different assumptions (looks like the EPA study they linked to assumes a typical car gets 22mpg, I get more like 33 on average, but then the short errands the bike replaces are likely lower fuel efficiency miles etc etc etc), or "the five U.S. states with the most Rad Power Bikes customers" may be cleaner parts of the grid than mine. I think it's safe to say that if you plan to put a couple thousand miles on the bike before it's trash you are on net saving the planet a little bit.

Also fun in this area: https://www.pearlizumi.com/pages/pedal-to-zero These folks tell you how many displaced car miles until the co2 to make your bike gear is made up (I have a ten year old version of that bright yellow jacket - if the number hasn't changed much since then I think I have covered the 25 miles long ago).

[grantmeaname]

Question for the mustachian hivemind

My walls were uninsulated and I got them filled with dense packed blown cellulose - 4 inches time R3.5 per inch for an R-Value of 14, minus the impact of the studs' thermal bridging. The bottom floor of the house is brick and the top floor is vinyl siding. I'm wondering about taking the siding off and adding rigid board insulation over the top of it on the top floor, if the math makes sense. I'm having trouble finding 1) how much does this cost and 2) how much energy savings would I see going from (less than) R14 to something in the 20s.

Any thoughts?

[Glenstache]

Question for the mustachian hivemind

My walls were uninsulated and I got them filled with dense packed blown cellulose - 4 inches time R3.5 per inch for an R-Value of 14, minus the impact of the studs' thermal bridging. The bottom floor of the house is brick and the top floor is vinyl siding. I'm wondering about taking the siding off and adding rigid board insulation over the top of it on the top floor, if the math makes sense. I'm having trouble finding 1) how much does this cost and 2) how much energy savings would I see going from (less than) R14 to something in the 20s.

Any thoughts?

There are a number of online building efficiency calculators for different types of wall and insulation construciton. That should be able to get you to a rough idea of the number of BTUs saved through efficiency at a given thermal gradient. If you have not already, look at the attic space first as that is usually easier and more efficiency gain per dollar spent. For the cost, I'd say you are basically looking at the cost of residing your entire house including trim around all the windows/doors. Tens of thousands of dollars unless your house is very small.

[grantmeaname]

Yep, attic is done, up to R49.

[nereo]

Question for the mustachian hivemind

My walls were uninsulated and I got them filled with dense packed blown cellulose - 4 inches time R3.5 per inch for an R-Value of 14, minus the impact of the studs' thermal bridging. The bottom floor of the house is brick and the top floor is vinyl siding. I'm wondering about taking the siding off and adding rigid board insulation over the top of it on the top floor, if the math makes sense. I'm having trouble finding 1) how much does this cost and 2) how much energy savings would I see going from (less than) R14 to something in the 20s.

Any thoughts?

Calculators are your friend here - very rough estimate on a generic home with your insulation and the wall assembly is probably around R11 (excluding heat loss from windows) with significant thermal bridging and air infiltration (see below). If you go with 2” insulation your wall will be much closer to R22, or cut your heat transmission through your walls in half, not accounting for additional benefits from air sealing.

as for what it costs, I can give a pretty decent estimates for cost, which is roughly $2 to $2.50 per square foot for materials, assuming you go with 1.5” or 2” and a rain gap between the insulation and siding. If you are hiring this out the estimates can vary wildly, but I’d expect to pay at least $5/foot and I had estimates of over $8 excluding cladding.

If you plan on replacing the siding anyway it’s a no brainer (and IMO an absolute must for lots of reasons). But it’s hard to make but the cost and (of you are doing it yourself) time if it’s a DIY

Whatever you do I’d avoid using less than 1.5” as it can give you problems with the dew point inside the wall and because the cost/labor difference is paltry between 1 and 1.5+. If your roof line (oveehang) allows it I’d absolutely do 2”

The biggest difference will be the end to thermal bridging, which is roughly 1/4 of a given wall and is roughly R5 in your wall assembly (2x4, drywall sheathing and cladding). If you go with rigid foam (as opposed to mineral wool) it will also greatly reduce air infiltration. The rain/air gap can double the life of siding, particularly anything wood, and will further reduce moisture problems in your wall.

Final thought - if you are removing siding that’s the best (and often only sensible) time to replace windows that are substandard. As it is you will have to decide whether you want to make window bucks  (“outie”) or keep your existing windows at the sheathing (“innie”) and build the insulation out from there. It’s mostly an aesthetics choice

[grantmeaname]

Calculators are your friend here - very rough estimate on a generic home with your insulation and the wall assembly is probably around R11 (excluding heat loss from windows) with significant thermal bridging and air infiltration (see below). If you go with 2” insulation your wall will be much closer to R22, or cut your heat transmission through your walls in half, not accounting for additional benefits from air sealing.

As in the past I'm having a lot of trouble finding a calculator and assumptions that comport well with reality. But I think that given that the bottom floor is brick so it would only be the top half of the house, I'd be looking at something like an R-14 or R-15 overall (before windows), or 26% lower heat loss through the walls (rule of thumb ~35% of heat loss), around a 9% overall energy savings, for a pretty substantial upgrade cost. I think that, like you say, I'll do this upgrade someday if wind or hail mean that I'm replacing my siding anyway.

I think that just leaves insulating the basement walls and floor (and as a result the rest of finishing the basement) as the last major efficiency project ahead. The ROI on that actually looks pretty good, but since we have way more space than we need above ground already I'm inclined to leave that for the future and just declare victory for the short term.

[Weisass]

I think that just leaves insulating the basement walls and floor (and as a result the rest of finishing the basement) as the last major efficiency project ahead. The ROI on that actually looks pretty good, but since we have way more space than we need above ground already I'm inclined to leave that for the future and just declare victory for the short term.

I'm curious what sort of basement you have, and how you are planning to insulate it? I have a dug basement, stone walls, and I am always interested in figuring out ways to improve efficiency. Would be interested to hear more about this part of your project.

[grantmeaname]

I'm not sure how much heat is lost through the basement wall and out the bottom of the slab - I've seen widely varying estimates from different rules of thumb, sources, and calculators. This article points to a DOE study finding a relatively meaty $300-400 of savings per year, but it points to a broken link so we can't examine its logic. The LBL energy savor calculator seems to think not much in the case of my house, even with the top insulated well and the basement insulated not at all, while many sources quote 20-30% and this calculator had incredible levels of heat loss far above my house's actual consumption just through the basement. My suspicion is that the correct answer is "not much heat at all" given the small temperature deltas between underground and conditioned air and given that recommendations and codes call for very little insulation even in new construction.

Not sure what sort of basement I have in terms of the question. It's 2/3 of the footprint of the house, so around 800 sq ft, with poured concrete walls and floor, no insulation under the slab, no insulation on the outer walls. One room is badly finished (badly enough we don't feel bad about taking it apart someday) and the remainder is unfinished. My house was built 1969 and I have an efficient natural gas furnace today with an eye towards an air source or ground source heatpump when it dies if not before. I've insulated walls and attics, air sealed the house and ducts, and gotten ceiling fans, so I'm out of 'low hanging fruit' projects.

The theoretically correct answer is to dig a trench on the outside of the basement, put on insulation and waterproofing out there, and then fill it back in. That's prohibitively expensive out here in the real world, so the next best answer is to insulate the inside. In an above-grade wall you want the wall to dry outwards so you have a vapor barrier - in a below grade wall the water is coming from the outside, so all you can do is 1) put in a vapor barrier to trap a bunch of moisture and mold right on the outside of the vapor barrier, or 2) use no vapor barrier, moisture permeable insulation like rock wool polystyrene, and moisture rated (purple or green) drywall. If you put foam in, you have to cover it with a fireproof layer (drywall) to be up to code, so I think that means do nothing until you're ready to finish the basement - and for us that involves an egress window and moving the HVAC system a bit, so it's longer term project.

This article is very, very good. There's also a ton to read here, not just on basements...

[NorCal]

I'm not sure how much heat is lost through the basement wall and out the bottom of the slab - I've seen widely varying estimates from different rules of thumb, sources, and calculators. This article points to a DOE study finding a relatively meaty $300-400 of savings per year, but it points to a broken link so we can't examine its logic. The LBL energy savor calculator seems to think not much in the case of my house, even with the top insulated well and the basement insulated not at all, while many sources quote 20-30% and this calculator had incredible levels of heat loss far above my house's actual consumption just through the basement. My suspicion is that the correct answer is "not much heat at all" given the small temperature deltas between underground and conditioned air and given that recommendations and codes call for very little insulation even in new construction.

Not sure what sort of basement I have in terms of the question. It's 2/3 of the footprint of the house, so around 800 sq ft, with poured concrete walls and floor, no insulation under the slab, no insulation on the outer walls. One room is badly finished (badly enough we don't feel bad about taking it apart someday) and the remainder is unfinished. My house was built 1969 and I have an efficient natural gas furnace today with an eye towards an air source or ground source heatpump when it dies if not before. I've insulated walls and attics, air sealed the house and ducts, and gotten ceiling fans, so I'm out of 'low hanging fruit' projects.

The theoretically correct answer is to dig a trench on the outside of the basement, put on insulation and waterproofing out there, and then fill it back in. That's prohibitively expensive out here in the real world, so the next best answer is to insulate the inside. In an above-grade wall you want the wall to dry outwards so you have a vapor barrier - in a below grade wall the water is coming from the outside, so all you can do is 1) put in a vapor barrier to trap a bunch of moisture and mold right on the outside of the vapor barrier, or 2) use no vapor barrier, moisture permeable insulation like rock wool polystyrene, and moisture rated (purple or green) drywall. If you put foam in, you have to cover it with a fireproof layer (drywall) to be up to code, so I think that means do nothing until you're ready to finish the basement - and for us that involves an egress window and moving the HVAC system a bit, so it's longer term project.

This article is very, very good. There's also a ton to read here, not just on basements...

I have to admit ignorance on the basement specific topic, but my general experience is that insulation is important, but rapidly suffers from declining marginal returns.

If you have ~R40+ in the attic, some level of insulation in the walls, and double pane windows, most other projects are going to get you sub-10% energy efficiency improvements.  This means the projects that will pencil out are usually cheap things like weather sealing, caulking around windows, etc.  If you're entire HVAC bill for the year is $1,000 (as an example), it's going to be hard to justify something that costs multiple thousands of dollars.

Obviously the details vary based on your utility costs and climate.  But at some point you're going to get better returns by just throwing up a few additional solar panels. 

[nereo]

It may be hard to justify it from a strictly economic, reduction of energy bills standpoint,  ust that’s not the only relevant measure. There’s a harder to quantify but still  very important comfort factor, your societal impact of needed less from the grid particularly during the highest energy needs, and of course the environmental consideration  that’s so tightly aligned with this thread and this forum.
What also gets overlooked at “R-gazing” is that green energy building and renovation is about more than reducing thermal transfer and getting super small energy bills. Done right it makes materials like siding and roofing last much longer, can improve health conditions (eg vapor management reduces mold, material choice limits formaldehyde and other toxins) and  at its absolute best encourages physical activity. Most of these benefits last for several decades.

A lot of projects won’t have a high ROI from a bean counting perspective, but that ignores the broader good.

[NorCal]

It may be hard to justify it from a strictly economic, reduction of energy bills standpoint,  ust that’s not the only relevant measure. There’s a harder to quantify but still  very important comfort factor, your societal impact of needed less from the grid particularly during the highest energy needs, and of course the environmental consideration  that’s so tightly aligned with this thread and this forum.
What also gets overlooked at “R-gazing” is that green energy building and renovation is about more than reducing thermal transfer and getting super small energy bills. Done right it makes materials like siding and roofing last much longer, can improve health conditions (eg vapor management reduces mold, material choice limits formaldehyde and other toxins) and  at its absolute best encourages physical activity. Most of these benefits last for several decades.

A lot of projects won’t have a high ROI from a bean counting perspective, but that ignores the broader good.

I have no disagreement in principle.  It's probably just where I put the dividing line.  I'm generally happy doing things where it will cut energy use and make things more pleasant & efficient, even if it's not a positive ROI project.  I just usually keep those in the couple hundred dollar range.  I don't think I'd personally go to the level of thousands of dollars in groundwork.

I'll also look at it different if I'm doing something new versus a retrofit.  For example, if I'm putting in new windows anyways, getting the most energy efficient windows possible is a great strategy.  But replacing builder grade dual pane windows with more expensive triple pane windows won't be a great use of resources.

[grantmeaname]

Anything that returns at least 4% (and isn't a declining/finite life asset like a furnace) is accretive compared to throwing the money in your stash and just paying the energy bills out of the earnings, right? I'm perfectly happy to do a project with a 10-15 year payback (6-10% post tax risk free ROI). Of course nothing else will have the stratospheric ROI and tiny payback periods of air sealing and a house's first insulation...

[A mom]

at its absolute best encourages physical activity.

Besides staircases, how can a house encourage physical activity? This is intriguing.

[NorCal]

Anything that returns at least 4% (and isn't a declining/finite life asset like a furnace) is accretive compared to throwing the money in your stash and just paying the energy bills out of the earnings, right? I'm perfectly happy to do a project with a 10-15 year payback (6-10% post tax risk free ROI). Of course nothing else will have the stratospheric ROI and tiny payback periods of air sealing and a house's first insulation...

I did the math on solar panels for my house, and the savings is about a 5% real return. So I use 5% instead of 4%, but your solar numbers may vary.  Essentially, if it has less than a 5% return, it’s cheaper to add another solar panel or two.

4% is a good number to use if solar is a less-good option, and you are comparing real returns instead of nominal returns.  I would even include a things like HVAC in this, as they are long lived assets where energy savings is protecting you from inflation.

 I also add in a personal mandate to eliminate anything that directly burns hydrocarbons, so my menu of options is a bit shorter, and does sometimes require low ROI projects.

[grantmeaname]

I agree with all of that. I just find it hard to affirmatively remove a working natural gas furnace if the ROI is 2% instead of 4%... while the ROI will be quite good if the furnace ever dies or energy prices go up to where they need to be to underwrite the green transition.

[rockeTree]

I for one am hopeful that the transition policy world will lead to permitting changes reflecting improved tech and smart controls that will allow me to replace my (highly efficient, not that old) gas furnace without structural additions or de-finishing the basement where my kid lives :-)

But I will surely size my roof solar to max generation even if absent the electric HVAC it is not the recommended choice.  Hoping to get that going within the next year.

[NorCal]

I agree with all of that. I just find it hard to affirmatively remove a working natural gas furnace if the ROI is 2% instead of 4%... while the ROI will be quite good if the furnace ever dies or energy prices go up to where they need to be to underwrite the green transition.

That's a fair point.  I did my HVAC changeover because Denver provided some especially good rebates that weren't going to last.  So it made sense at the time, and I wouldn't have done it without those incentives.

This is also an item that has less urgency. 

Every state is a bit different, but my electricity here in Colorado produces about 1lb of emissions per kWh.  Natural gas produces 11.7lbs per therm.  Based on my heat pump usage so far, the emissions are roughly break-even between the two today.

Except my utility is getting to ~80% renewables by 2030 and shuttering all of their coal power by then.  So while my heat pump will have much lower emissions over its lifecycle, there are negligible emissions savings today.

It's fair to say (in CO at least) that you're doing the right thing as long as you aren't installing new gas-fired appliances.  But there is no rush to replace them.

Search for your utility and "emissions intensity" to see where your utility stacks up.  The answers to this vary heavily by location.  Some place in the Pacific Northwest have incredibly low emissions intensity because of the massive amounts of hydropower, while coal fired states like Wyoming and West Virginia are around 2lb/kWh.  Most states seem to cluster around the 0.8-1.2lb/kWh mark

Edit: Here's some sources of numbers on the topic.  I like the EPA's visualization tool for electricity, although it is based on where electricity is produced and not sold.  Trying to find a number for your individual utility would give you a better answer.  I also linked the emissions associated with various other fuels from the EIA.

https://www.epa.gov/egrid/data-explorer
https://www.eia.gov/environment/emissions/co2_vol_mass.php

[grantmeaname]

Yep - a very good analysis to do, and agree that those factors all look pretty good in CO. I'm in a red state with little nuclear energy, very little renewable contribution, no green incentives, and in fact financial penalities in some cases (like an EV registration surcharge so big it offsets ~20% of the annual gas savings).

[Indio]

Indoor air quality has been nagging at me for 1.5 yrs so I fell into the trap of purchasing two air monitors. One measures CO2 and the other measures indoor AQI, PM2.5, TVOC, HCHO, temp and humidity. I live in a 100 yo home that has been insulated over the years, but not massively because I've always felt that homes need to breathe to avoid radon buildup. It's not a rational perspective because I have a radon remediation system but it doesn't remove all basement radon. the lack of an airtight home doesn't bother me since we usually put on extra layers. Here's the rub -- these air monitors have altered my reality about air quality.

So the CO2 levels are difficult to control in winter. The bedrooms aren't large so when we wake up in the morning the CO2 sensors have super high reading. A rating over 800 is considering unsafe from a cognition perspective. I usually sleep with the window open a crack and the heat pump off because I prefer being under lots of blankets. The kiddos like the heat on at night and the windows closed. The reading in their rooms is in the 2000+ range. I've figured out that if I turn on the central bathroom fan and open all the windows, I can get the house back to the 450 range every morning.

The air monitor that measures toxins uncovered lots of issues, even though I thought we had good levels because I've always been cautious about no VOC paint, new furniture without glues, mattresses, no MDF furniture, etc. The heat pumps, old hair dryer, ammonia in compostable kitty litter, hair straightening products, cooking on an electric stove, perfumes, and numerous other things I didn't used to think about are all spiking the toxins and it takes about 24 hours to "clean" the air. Since we spend most of our time in the living room, I installed a permanent hepa air filter but thinking I may need to put in a larger filtration system to remediate faster. Looked at this system that uses a box fan with 5 hvac filters around it. Haven't gotten there yet but it's in the back of my mind that I may need to make other changes.

If you're interested in a little light reading on the topic, check out this article. https://www.theatlantic.com/health/archive/2023/02/carbon-dioxide-monitor-indoor-air-pollution-gas-stoves/672923/

[RWD]

I live in a 100 yo home that has been insulated over the years, but not massively because I've always felt that homes need to breathe to avoid radon buildup. It's not a rational perspective because I have a radon remediation system but it doesn't remove all basement radon. the lack of an airtight home doesn't bother me since we usually put on extra layers.

I believe the correct way to get air exchange in a more airtight home is with ERV (energy recovery ventilation) or HRV/MVHR (heat recovery ventilation/mechanical ventilation heat recovery.

[eyesonthehorizon]

at its absolute best encourages physical activity.

Besides staircases, how can a house encourage physical activity? This is intriguing.

Not sure if this is what others have in mind, but my activity levels peak in spring & fall when my house is naturally in a comfortable temperature range, then trough in summer & when it gets genuinely cold in winter when I accept less than ideal indoor temps in exchange for energy conservation. You're simply more likely to want to get up & move around when it's not unpleasantly warm indoors, or when doing so doesn't mean emerging from the comfort of a blanket cocoon (possibly disturbing pets along the way.) Not having asthma from mold growth or other air quality issues also promotes physical activity.

There's also the up-front activity of doing the installation work on the home, I suppose, but that's one-off.

[NorCal]

Indoor air quality has been nagging at me for 1.5 yrs so I fell into the trap of purchasing two air monitors. One measures CO2 and the other measures indoor AQI, PM2.5, TVOC, HCHO, temp and humidity. I live in a 100 yo home that has been insulated over the years, but not massively because I've always felt that homes need to breathe to avoid radon buildup. It's not a rational perspective because I have a radon remediation system but it doesn't remove all basement radon. the lack of an airtight home doesn't bother me since we usually put on extra layers. Here's the rub -- these air monitors have altered my reality about air quality.

So the CO2 levels are difficult to control in winter. The bedrooms aren't large so when we wake up in the morning the CO2 sensors have super high reading. A rating over 800 is considering unsafe from a cognition perspective. I usually sleep with the window open a crack and the heat pump off because I prefer being under lots of blankets. The kiddos like the heat on at night and the windows closed. The reading in their rooms is in the 2000+ range. I've figured out that if I turn on the central bathroom fan and open all the windows, I can get the house back to the 450 range every morning.

The air monitor that measures toxins uncovered lots of issues, even though I thought we had good levels because I've always been cautious about no VOC paint, new furniture without glues, mattresses, no MDF furniture, etc. The heat pumps, old hair dryer, ammonia in compostable kitty litter, hair straightening products, cooking on an electric stove, perfumes, and numerous other things I didn't used to think about are all spiking the toxins and it takes about 24 hours to "clean" the air. Since we spend most of our time in the living room, I installed a permanent hepa air filter but thinking I may need to put in a larger filtration system to remediate faster. Looked at this system that uses a box fan with 5 hvac filters around it. Haven't gotten there yet but it's in the back of my mind that I may need to make other changes.

If you're interested in a little light reading on the topic, check out this article. https://www.theatlantic.com/health/archive/2023/02/carbon-dioxide-monitor-indoor-air-pollution-gas-stoves/672923/

I have a few anecdotal points of things we've seen around this.  I installed an Airthings air quality monitor as well.  I like it as it also picks up Radon.  It turns out that one of the energy wasters in my home was a comically oversized radon fan which I was able to replace with an energy start model for about a 65% energy reduction.

Cooking always kicks up the PM2.5 levels to a bad amount.  But having the monitor helped a lot.  I can both run the vent fan for a better amount of time and I try to mostly use the rear burners.

My old furnace had the standard type of air filter.  Which didn't do much to the PM 2.5 levels, even with filters that supposedly got them.  It would take a few hours for the levels to go down.

The company that installed my heat pump quoted me an ERV at $3k.  I liked the idea of it, but it was more than I wanted to pay.

But they did install an Aprilaire filter.  Which is just a bigger fancier HVAC air filter for ducted systems.  This thing clears the air in under 20 minutes as long as the air handler is running.

https://www.aprilaire.com/whole-house-products/air-purifiers/model-2410

[Glenstache]

Indoor air quality has been nagging at me for 1.5 yrs so I fell into the trap of purchasing two air monitors. One measures CO2 and the other measures indoor AQI, PM2.5, TVOC, HCHO, temp and humidity. I live in a 100 yo home that has been insulated over the years, but not massively because I've always felt that homes need to breathe to avoid radon buildup. It's not a rational perspective because I have a radon remediation system but it doesn't remove all basement radon. the lack of an airtight home doesn't bother me since we usually put on extra layers. Here's the rub -- these air monitors have altered my reality about air quality.

So the CO2 levels are difficult to control in winter. The bedrooms aren't large so when we wake up in the morning the CO2 sensors have super high reading. A rating over 800 is considering unsafe from a cognition perspective. I usually sleep with the window open a crack and the heat pump off because I prefer being under lots of blankets. The kiddos like the heat on at night and the windows closed. The reading in their rooms is in the 2000+ range. I've figured out that if I turn on the central bathroom fan and open all the windows, I can get the house back to the 450 range every morning.

The air monitor that measures toxins uncovered lots of issues, even though I thought we had good levels because I've always been cautious about no VOC paint, new furniture without glues, mattresses, no MDF furniture, etc. The heat pumps, old hair dryer, ammonia in compostable kitty litter, hair straightening products, cooking on an electric stove, perfumes, and numerous other things I didn't used to think about are all spiking the toxins and it takes about 24 hours to "clean" the air. Since we spend most of our time in the living room, I installed a permanent hepa air filter but thinking I may need to put in a larger filtration system to remediate faster. Looked at this system that uses a box fan with 5 hvac filters around it. Haven't gotten there yet but it's in the back of my mind that I may need to make other changes.

If you're interested in a little light reading on the topic, check out this article. https://www.theatlantic.com/health/archive/2023/02/carbon-dioxide-monitor-indoor-air-pollution-gas-stoves/672923/

I have a few anecdotal points of things we've seen around this.  I installed an Airthings air quality monitor as well.  I like it as it also picks up Radon.  It turns out that one of the energy wasters in my home was a comically oversized radon fan which I was able to replace with an energy start model for about a 65% energy reduction.

Cooking always kicks up the PM2.5 levels to a bad amount.  But having the monitor helped a lot.  I can both run the vent fan for a better amount of time and I try to mostly use the rear burners.

My old furnace had the standard type of air filter.  Which didn't do much to the PM 2.5 levels, even with filters that supposedly got them.  It would take a few hours for the levels to go down.

The company that installed my heat pump quoted me an ERV at $3k.  I liked the idea of it, but it was more than I wanted to pay.

But they did install an Aprilaire filter.  Which is just a bigger fancier HVAC air filter for ducted systems.  This thing clears the air in under 20 minutes as long as the air handler is running.

https://www.aprilaire.com/whole-house-products/air-purifiers/model-2410

Note on sub-slab depressurization fans (ie, some radon fans). If these are properly installed, the method includes drawing vacuum with a fan and measuring pressure drop at different distances from the fan location under the target slab. The fan is then sized/selected for installation to create that pressure drop. The size of the fan and radius of influence is controlled by the vapor permeability of the subslab soils. I obviously have no way to know if the installer did this or just chose a big fan and called it good at your place. However, if the proper protocol was followed, reducing the fan size could make the system less than fully effective.

[nereo]

at its absolute best encourages physical activity.

Besides staircases, how can a house encourage physical activity? This is intriguing.

Not sure if this is what others have in mind, but my activity levels peak in spring & fall when my house is naturally in a comfortable temperature range, then trough in summer & when it gets genuinely cold in winter when I accept less than ideal indoor temps in exchange for energy conservation. You're simply more likely to want to get up & move around when it's not unpleasantly warm indoors, or when doing so doesn't mean emerging from the comfort of a blanket cocoon (possibly disturbing pets along the way.) Not having asthma from mold growth or other air quality issues also promotes physical activity.

There's also the up-front activity of doing the installation work on the home, I suppose, but that's one-off.

Oops, I completely failed to respond @A mom - sorry. This falls into one of my favorite niche subjects

Basically, layout and design can alter how we move and interact with our surroundings. As examples, if you built bicycle storage someplace between your door and the road you become far more likely to take your bike than if you keep them stored in a garage in front of your cars (the car then becomes “easier” to take than the bike). If you want to facilitate dining Al fresco then have as few barriers between the kitchen and your outdoor eating area, including making the transition between inside and outside as seemless as possible. This includes have no steps, a low/no threshold, few turns and having a covered awning or roof line as you transition between inside and outside. For any activity you want to encourage, provide lines-of-sight and remove barriers. Make a convenient and clean space to transition gear (eg boots, coats, hats) that’s out of the weather.

That’s the general idea, the specifics are always down to the individual, site and activity. There’s a lot of data showing how various tweaks that seem almost unnoticeable influence our behavior. I remember reading about one study that showed a patio door without a raised threshold resulted in it being used more often than one with a 3/4” high threshold. Wild. Apple Inc demonstrated something similar with productivity, and designed their flagship campus to not have these floor divisions between rooms for that reason.

[A mom]

Thanks eyesonthehorizon and nereo for your responses regarding houses and activity levels. I can certainly agree that when it gets too warm or too cold inside my activity level drops. Nereo your information about ease of access and thresholds makes a lot of sense. I’ve found that just having a garage with a person door that faces the driveway, makes biking seem much easier because I don’t have to open and close the garage door, which takes longer. Likewise, we replaced a patio with a slightly raised deck and now go out there much more often than when there was a single step down to the patio. Thanks for the info!

[NorCal]

Indoor air quality has been nagging at me for 1.5 yrs so I fell into the trap of purchasing two air monitors. One measures CO2 and the other measures indoor AQI, PM2.5, TVOC, HCHO, temp and humidity. I live in a 100 yo home that has been insulated over the years, but not massively because I've always felt that homes need to breathe to avoid radon buildup. It's not a rational perspective because I have a radon remediation system but it doesn't remove all basement radon. the lack of an airtight home doesn't bother me since we usually put on extra layers. Here's the rub -- these air monitors have altered my reality about air quality.

So the CO2 levels are difficult to control in winter. The bedrooms aren't large so when we wake up in the morning the CO2 sensors have super high reading. A rating over 800 is considering unsafe from a cognition perspective. I usually sleep with the window open a crack and the heat pump off because I prefer being under lots of blankets. The kiddos like the heat on at night and the windows closed. The reading in their rooms is in the 2000+ range. I've figured out that if I turn on the central bathroom fan and open all the windows, I can get the house back to the 450 range every morning.

The air monitor that measures toxins uncovered lots of issues, even though I thought we had good levels because I've always been cautious about no VOC paint, new furniture without glues, mattresses, no MDF furniture, etc. The heat pumps, old hair dryer, ammonia in compostable kitty litter, hair straightening products, cooking on an electric stove, perfumes, and numerous other things I didn't used to think about are all spiking the toxins and it takes about 24 hours to "clean" the air. Since we spend most of our time in the living room, I installed a permanent hepa air filter but thinking I may need to put in a larger filtration system to remediate faster. Looked at this system that uses a box fan with 5 hvac filters around it. Haven't gotten there yet but it's in the back of my mind that I may need to make other changes.

If you're interested in a little light reading on the topic, check out this article. https://www.theatlantic.com/health/archive/2023/02/carbon-dioxide-monitor-indoor-air-pollution-gas-stoves/672923/

I have a few anecdotal points of things we've seen around this.  I installed an Airthings air quality monitor as well.  I like it as it also picks up Radon.  It turns out that one of the energy wasters in my home was a comically oversized radon fan which I was able to replace with an energy start model for about a 65% energy reduction.

Cooking always kicks up the PM2.5 levels to a bad amount.  But having the monitor helped a lot.  I can both run the vent fan for a better amount of time and I try to mostly use the rear burners.

My old furnace had the standard type of air filter.  Which didn't do much to the PM 2.5 levels, even with filters that supposedly got them.  It would take a few hours for the levels to go down.

The company that installed my heat pump quoted me an ERV at $3k.  I liked the idea of it, but it was more than I wanted to pay.

But they did install an Aprilaire filter.  Which is just a bigger fancier HVAC air filter for ducted systems.  This thing clears the air in under 20 minutes as long as the air handler is running.

https://www.aprilaire.com/whole-house-products/air-purifiers/model-2410

Note on sub-slab depressurization fans (ie, some radon fans). If these are properly installed, the method includes drawing vacuum with a fan and measuring pressure drop at different distances from the fan location under the target slab. The fan is then sized/selected for installation to create that pressure drop. The size of the fan and radius of influence is controlled by the vapor permeability of the subslab soils. I obviously have no way to know if the installer did this or just chose a big fan and called it good at your place. However, if the proper protocol was followed, reducing the fan size could make the system less than fully effective.

This is why I bought the air quality monitor with radon detection for the house to begin with.  I wanted to be sure I wasn't doing something stupid. 

The inspector noted that the system wasn't installed to code when we bought the house, as the radon vent was routed through the house instead of outside the house.  I feel pretty confident the builder just slapped the cheapest components they could on it without doing anything correctly or professionally  It was a trend in my neighborhood. 

I've tested it out by turning the radon fan off when we went on vacation, and I watched the levels spike.  But they came back down with the new lower powered fan.  So I feel pretty good about it.  But yea, I don't have a professionals view on it.