We removed wall (plaster and lathe), added walls, re-did all electrical and plumbing, added half bath, full remodel Of existing bathroom, expanded kitchen.  

Same for the foundation, roof, electrical and plumbing systems. 

never heard of one running off propane, unlike natural gas or electric.

The insurance company may cover some or all of the restoration costs.Scope of Work and Budget:Detailed Inspection: Get a comprehensive inspection to identify all areas of damage, including hidden issues like electrical, plumbing, and HVAC systems.Cost Estimation: Obtain detailed cost estimates for the restoration or rebuilding process from licensed contractors experienced in fire-damaged properties.Environmental Hazards:Asbestos and Lead Testing: Older properties may contain asbestos or lead, which can become hazardous after a fire.

Had one that we found off-market but things fell through during the inspection (electrical and plumbing issues that we didn't have the capital to pay for and the seller wouldn't budge on). 

Last night I heard about a friend who had their electric bill go from $100 per month to $800 per month because the landlord did a repair to two of them and cross wired them causing my friend’s to short and use 8X the amount of energy for the month.

Flooring, walls, roof, electrical, egress with windows and I think there is something about having a door that exits the home... not just into the home. 

Before you spend any money, you just need to price everything out (i.e. cost of homes, moving costs, installation, hook ups such as electrical, water, etc). 

Taking some of that space for the bedroom would only require framing in a non-load-bearing wall, closet, and bedroom door, plus adding a few electrical outlets/switches, and then finishing with insulation, drywall, paint, and trim. 

It bugs me because I wasn’t going to rent to them initially because of the girlfriend’s low credit score, but he has a good job and they did own a home a few years back.