Realise the last post was a little negative towards your model. I hope it is clear that it is only a view, rather than criticising what you are trying to do. Sometimes models can be incredibly powerful (e.g. classic MMM of looking at owning a <3 year luxury car for the next 20 years) and demonstrate how crazy it is and how much more quickly you can FIRE if you don't. That is powerful stuff and even if investment returns on the saved cash are 3% or 6% the maths is still powerful. Unfortunately I don't think the buy/rent models can be so compelling for the reasons outlined before as in the end, one is a bet on house prices and one a bet on stock markets.
At least when I evaluate these things I look at things more personally. I know I have two young kids and am not likely to move for a long time and don't mind / quite like doing things around the house. I know I cannot quite rid myself of the 'my home is my castle' mentality. I don't want a landlord to tell me what I can and cannot do. I know interest rates are very low and I can borrow very cheaply (real rate zero presently) and if this changes, I can pay down my mortgage using other funds. I believe house prices will remain supported by the fact that we are still not building enough houses in the UK, although I don't think they will rise much more than inflation. I know that my mum lives in our extension so few rentals would be suitable!
However, fast forward 10+ years and at 50 the kids will be heading out the door. I know we will want to travel and will value flexibility. I also know I don't want to be maintaining a big family house with no kids in so will sell then. Feels like you see too many older people struggle financially and physically to stay in that 4/5 bedroom 'forever home' once the kids have gone. Seems weird to me. Cash the house in, get a great smaller place in a different location which suits who you are now, not the family you were.
Wow. Turned into another rant. I have been up since 4am sorry!