$38k is over $3000 a month. If you only need $1500 a month to live on and you make more than $3000, won't you already be at a >50% savings rate as soon as the house is paid off?
Before we get into my tips, I'll echo James: that's really fantastic work to care for a family of 5 and homeschool a sizable class on $18k a year! I'm way impressed! You're solidly in
ERE territory!
Here are some of my specific tips for savings, if you want to try and drive your expenses lower.
I'd have your husband look into hypermiling techniques. If he only drives 800 miles a month (40 miles*20 workdays), and he can hypermile the civic at 40mpg (seems reasonable based on a quick search of hypermiling forums), you've dropped his work gas use to 20 gallons a month, or $70. Even after your van driving is added to that, you should be
nowhere near $225. He could also look into a motorcycle for further savings (Bakari has a
fantastic blog post about it not being as scary as you might think).
Do you think you could cut down your $100 a month car repair expense by insourcing more of the repairs? Intuitively, as the driver of a single 10-year-old-but-unreliable car, it seems like you might be able to squeeze some money out of that category, and it is 7% of your total monthly expenses.
Your utility bills may also have room to be cut, although not knowing your prices, your market, and your home, it's hard to say.
Michael Bluejay has a great, up-to-date website for cutting electricity and natural gas usage if you can get past the 1995-era web design. MMM
has a series of posts on utility costs. And
as Michael Bluejay notes, electricity costs vary even in the same place from the same provider, so you may be able to
cut costs by switching providers (while you're at it, you could shop around for insurance). Regarding your telecom bill specifically, I'd urge you to check out I.P. Daley's now-famous
superguide.
Your grocery bill is impressively low, but you might be able to drive it even lower. How do you feel about a couple of meatless meals a week? Despite my reservations, I was pleasantly surprised how many meatless meals I can make that aren't made of painful faux-meat and meat-substitute: beef with broccoli, without the broccoli; pasta bakes with just veggies and tomato sauce; summer grilled or winter roasted mixed vegetables; eggs and pancakes. Do you grow any of your own herbs, fruits and vegetables? Could you expand your growing if so? Do you coupon? Do you
shop with your middle finger? I'm sure you already do a couple of these things based on your impressively low costs, but the ones you don't could help you feed your family even cheaper!
If you want reading recommendations, the slightly-outdated
Tightwad Gazette and
Early Retirement Extreme (author's referral link, not mine) are the first options to come to mind.
Finally, you could try and raise your income to address the other half of the savings rate fraction. It's hard to be prescriptive without knowing your situation's specifics, but MMM notes that it's easier to raise a low income than cut low expenses (pep talk
here, can't find the other relevant posts today for some reason).