Sometimes tenants ask the landlord to build in the furniture. I was working with a client who wanted a built-in reception desk, walls and then desks behind the walls. I suspect he thought this was going to be free as it was part of the build out. The client was miffed when the landlord wanted to charge more for the rent.
Landlords will build out the space. Generally, they have a specific number they are willing to invest in improvements and anything beyond that is on the tenant’s dime.