Just caught up reading the discussion about housing - it definitely makes sense to me to account for future potential house maintenance expenses, such as boiler replacement, roof, etc. As long as I haven't FIREd yet then for me personally that is accounted for by having at least 2 years' worth of typical expenses available in a format I can access right away if needed, and then potentially doing OMY or trying to earn more income to recover the amount.
I'm a bit unconventional for this board - I'm not actually sure when/if I will properly FIRE, since I became disabled after I discovered FIRE but before I started working and have always had such a low income. I wanted to do the 5-10 years to FIRE originally, but without full time work, I wasn't able to. Actually, for me, the main thing applying FIRE principles is doing is allowing me to live well at *all* on the amount I'm able to learn. Even though my expenses are so low, because of the low income it's still only 30-40% savings. But I avoid a lot of the financial stress and/or being forced to live with people they hate that I see a lot of disabled people I know experience. (Specifically the ones who, like me, also can't work full time.) And I'm hoping to improve my income at some point if I can, so that I can actually do the RE part of FIRE sometime.
But yes, in light of my FIRE goal being unconventional that way, I'm lightyears ahead of most disabled part time workers in that I *can* actually afford major work on the house if I need to.
About rent, it definitely doesn't make sense for me to always write my expenses as *if* I was paying mortgage or rent. What I want to know is am I doing enough work this year in particular or not, mostly. My new job (starting in January) is 18.5 hours a week and a bit less than £9000 a year. If I were renting I'd need to side-hustle an extra couple of thousand, but since I'm not, then I can rest safe in the knowledge that any side hustling I try is out of fun and not necessity and I don't need to wear myself out over it.
We don't really get most natural disasters in the UK, but if the house burnt down in a fire, then a) we have house insurance, and b) I have enough saved to rent somewhere right away while I figured out what I was doing, and to pay the amount needed for a rental lifestyle for over a year. Plus, I'd try to find somewhere where I wasn't renting alone, which would bring my expenditure back down again. It's only if I were solo renting that I'd be over the £9000 figure.
So yes, for most people who aren't renting or paying a mortgage, it doesn't really make sense to calculate all their expenses as if they were, as long as they have enough liquidity to cover themselves to rent for a while if they needed to while they reassessed the situation.