***NOT taking off the old shingles, is only saving you around $1K (give or take)... if you're already going through all the hassle of new system, bite the bullet and do it correctly.When you remove the old layers, you can then: do any necessary repairs; possibly install ISO boards (insulation boards) smoothly; install the good membrane (not simple felt!)

I have an employee that bought a 40X15 (600 sq ft) prefab metal building for 11,000 then spent 7,000 turning it into a home, for the 7k he was able to super insulate it , create a single bedroom, a full bathroom with laundry, and a small kitchen.

I like to point out to my potential tenants that I added insulation or replaced a FPE electric panel to show that I don't just slap lipstick on my properties to make a quick buck....I would think the same would be true of appraisers.  

We are now upon April 2024, and at the rate things have been going, still have a ways to go (finish ducting for forced hot air, insulation, sheet rock, paint, flooring, kitchens, bathrooms, finishes, and anything I am missing to bring the units to whole).

I purchased a 1 BR 900sqft condo in 2021 with a depreciable tax basis of ~$275k and spent most of 2021 and first half of 2022 renovating the property (new appliances, flooring, painting, furniture, bathroom renovation, new kitchen countertops, new electric heaters, insulation, fireplace/pellet stove).

"Buyer to receive $5000 credit at closing, Buyer agrees to replace subfloor with 3/4 plywood, mildew resistant and sound proof flooring insulator"Obvious labor is expensive, What are your thoughts on this.. the actual subfloor is fine but its in the contract to install new subfloor anywaywith the "replace subfloor", could I install new 3/4 plywood over the existing subfloor which technically i am replacing the subfloor or do i need to discard the old subfloor and install the 3/4 plywood??  

Or for minimal work, drill small holes near the pipe and spray foam insulation.

I'd like to finish it with insulation, electrical, dry wall, treaded stairs, etc. 

But from the reports I've read, a ski resort is more insulated (not free though) from declining snow pack at higher altitudes (so you can keep that in mind).

Where it comes into play here is the older buildings with asbestos pipe insulation, or asbestos in joint compound and window caulking.