I just completed an inspection on a small older home with a detached 2 car conversion. I have confirmed through the local Assessor and Building Department that the conversion is not permitted. The conversion features a kitchenette including a gas stove/range, a full bath, and a bedroom. Similar un-permitted additions are not typical in the subjects market. Although not typical, there is little market data suggesting any adverse effect on market value. Normally, I would give a cost to cure to remove all contents of the kitchenette, remove all interior walls, remove the bathroom, and re-install a garage door. This would restore the garage back to its original design and value would still be given to the garage. Does this sound correct? Any other recommendations on how to handle this??
Appraise as is, since lender does not want it subject to retrofit. Based on your comments above, this illegal (illegal as in non permitted), conversion to living area is not typical of area. Check with RE agents, but it is more probable, since it is atypical, that most buyers want a garage that functions as a garage, not as non permitted living area in this market.
First thing is to interview some agents..how do they think most buyers would react? Would most buyers want a working garage? Which means, depending on C2C (if motor and tracks are still in place, etc), a good many buyers might pay a bit less for this since they have to pay to put it back to functional garage, or at best not pay any more for it.
I would provide a cost to cure estimate, even if it is appraised "as is". IF nothing else, will help you determine market reaction to a degree...if C2 C is $1000 to remove drywall and kitchen, that is marginal, and might not affect value much, if C2C is $5000 to install motor, tracks get it re inspected to working condition and possibly replace garage door, that is an amount that might affect value if most buyer preference is for a working garage.
The area has some value in market as a garage, albeit a garage with some repair issues to typical buyer perhaps. ( and if most lenders would require retrofit to working garage if a sale, could affect value to buyers)