So Why o Why was asked why he didn't post his net worth over his gross annual consumption rather than gross annual income. He pointed out the future was unknown, and it was easier to compute based on a known number (annual income). His own desire included a future house which was larger than the current house.For my own calculation, I am paying off the house on a 10 year note. So then one must ask- how do you compute housing into a FIRE calculation?Here are some alternatives:1) Included current housing costs, ignoring the future possible paydown. For many, especially renters, this is completely accurate (sans inflation).2) Plan your estimation based on your future FIRE date to have the place owned on that date- that is, if your FIRE date is past your note paydown date, then your housing cost is reduced to taxes and insurance. If your FIRE date is before this, then allocate the necessary funds to pay off the house as part of the FIRE fund.3) Plan your estimation where you plan to re mortgage the residence to a new 30 year plan at the date of FIRE. Thus, plan that you will refinance at the point you are FIREing, and thus will have a steady cost for your future which can be calculated now, assuming a specific interest rate. So if you own a $500,000 house and will have $200,000 paid off at FIRE date, then you will refinance for $300,000 at that future date. This reduces your forced outlay of cash by freeing up forced spending going to mortgage to allow it to go to other necessities.This all is wrapped up in the question of- how do I want to handle the future uncertainty of market returns versus my known costs of paying off a debt? I am positing that an unknown amount (of market return) can increase your required FIRE funds for larger forced outlays of cash (such as a mortgage).