what tax year? the instructions for form 8829 say its only to be used for schedule C see below
in forms mode for schedule C for 2023 there are separate asset entry worksheets other than auto, home office (no M or N) and asset entry worksheet for home office types M and N this also requires entries for the 8829 worksheet
the proration of cost for depreciation purposes comes from the entries on the 8829 worksheet
in step mode when you come to schedule C > business expenses page the last item listed is home office expenses
if you read the 8829 instructions it says this
Use Form 8829 to figure the allowable expenses for business
use of your home on Schedule C (Form 1040) and any carryover
Who cannot use Form 8829. Do not use Form 8829 in the
following situations.
• You are claiming expenses for business use of your home as a
partner or you are claiming these expenses on Schedule F ( i would also assume schedule e rentl/royalty}
(Form 1040). Instead, complete the Worksheet To Figure the
Deduction for Business Use of Your Home in Pub. 587. (You
cannot claim expenses for business use of your home as an
employee.)
https://www.irs.gov/pub/irs-pdf/p587.pdf
