One unit is fully renovated: hardwood floors, updated kitchen/baths, new paint, electrical, furnace, hot water tank, and roof.The other unit needs full rehab: plumbing, furnace, flooring, drywall, paint, kitchen, baths, tank, and misc.We estimate $40K in rehab with an ARV of $250K–$255K.Rent Potential:Market: $1,300–$1,400/unitSection 8: Up to $1,600–$1,700/unitStrong cash flow potential.

I was happy about this but then the sellers disclosed underground oil tank on the day of the inspection, found out that half of the house’s backyard falls is wetlands that is part of a conservation area and high radon level in the well water.

One unit is fully renovated: hardwood floors, updated kitchen/baths, new paint, electrical, furnace, hot water tank, and roof.The other unit needs full rehab: plumbing, furnace, flooring, drywall, paint, kitchen, baths, tank, and misc.We estimate $40K in rehab with an ARV of $250K–$255K.Rent Potential:Market: $1,300–$1,400/unitSection 8: Up to $1,600–$1,700/unitStrong cash flow potential.

The ceiling tiles were wet and water came out onto the floor. 

From our experience, success comes down to a few key factors:Amenities: Hot tub, fire pit, water access, kayaks, and a well-equipped kitchen all go a long way.Bedroom count: Aim for 4+ bedrooms to appeal to larger groups and families.Year-round appeal: Properties that work for both summer and winter (e.g., near ski resorts or with cozy winter vibes) help maintain strong occupancy.Happy to chat or share more if you're seriously exploring STR investments.

I'm not talking about slums, or cold water flats, which are illegal but simply apartments that have some wear on them. 

My thought for this was to give more detail on the expense side, giving rough estimates for things like: insurance, elec, water, gas, internet, maintenance, cap ex, landscaping, and cost to furnish. 

I fear you got yourself into some hot-water on this. 

We never had one cause water damage, as there is never more water in it than can fit in the tub.

Is it on the lake with direct water access or across the street with water access through a common way within the development?