Most likely all new mechanicals, windows, a fair amount of framing, insulation, etc., etc.

Roof white owned all hispanic.. hvac white owned white workers. dry wall  white owned all hispanic  insulation white owned all hispanic.. flat work hispanic owned all  hispanic workers,  floors and tile  Eastern block owned Eastern block workers speak no english do incredible work.

I hear you.I have been buying distressed real estate for 40 years now.. so I understand the moral struggles we go through.. one reason I like buying vacant foreclosures and off of auction . com your insulated your making your best offer and off you go.the second your talking to a home owner and you know the house is really worth 100k and your trying to snag it for 70k I just find it hard to equate that to doing the moral thing.. :)I had a good friend who wanted to go back to work .. very deeply religious.. and I said well lets buy foreclosures in Bend he last one day.. he said I can't do that I donate to the church to help people keep their houses and can't very well buy them..

It's reasonable to say the market is somewhat "insulated" relative to many other markets in the country. 

You have to consider insulation and heating/cooling too.

You may need to replace insulation, sheetrock, or even framing material.The only way I would touch it is to have a contractor give me an estimate for renovation, then lower the price far enough to handle that renovation.

During the last crash this town was highly insulated as well, simply because the military makes up about 15% of the total population here and they won't have any negative job ramifications and that stability trickles into the market. 

Then it's simple, build the home, find crews to do the work (you should already have them basically from the prior step), excavation, concrete, sealing, framing, roof/gutters/siding, windows, insulation drywall, plumbing, HVAC, electrical, finishes, etc. basically in that order.

Also, because most baseboard heaters do not have fans they only heat a very small area causing the tenants to set them very high and the heaters cannot keep up. 3rd is to check the insulation in the attic and sidewalls.

If it's attached , then you have to make sure it has the same heating and insulation component as in the main room.