Living expenses aren’t assessed the same by every bank
When applying for a home loan, the bank compares the living expenses you declare against its own minimum benchmark, known as HEM.
The bank will use their benchmark number or your expenses whichever of the two is higher, so if you are below their benchmark this can have a material impact.
For a single applicant with no kids earning $100k, the lowest lender benchmark is $1,718 per month and the highest was $2,255.
For a couple with one child earning $125k each, it ranges from $4,532 to $5,391 per month.
In a completely vanilla scenario, the lender using the lowest living expense figure also provided the highest borrowing capacity.
Just another reason borrowing capacity can vary so much from one bank to another.