There are 2 issues, when calculating if you can retire. First, do you have enough so that it wont run out by the time you die. Second, will you have enough cashflow at all times.
For instance the house question. If you rent, and rent is $1000/month, then you need 300k in accessible investments to cover that. If you own a house outright, the value of the house doesn't really matter, it just decreases your monthly expenses because you don't need to pay a mortgage or rent. You can go either way in your decision making, just know that you need to include your mortgage/rent in your "spending" number.
The retirement accounts are another damper on cashflow but not necessarily on "will you run out before death." The question changes to, how much do you need to last until you can access those retirement accounts? The 25x your spending number is based on your savings lasting 30 years. So if you have 25x you spending in accessible non-retirement accounts, you could probably safely retire 30 years before you can access your retirement accounts. But you better have another 25x in the retirement accounts by that point. (Note this is pretty darn conservative but it is the math for retiring in your late 20's - early30's)