The environmental regs changed around that time as well as many local codes like fire access, sewer (preferred over septic due to clean water act), water availability etc.So when you look at the requirements vs. the value created it becomes financially infeasible...or another development like SFR or a medium density MFR is more feasible.

There's also the question of whether the contractor would even replace and warranty the unit without the other components being replaced too.

I do all that, in addition to income requirements, employment verification, tenancy history verification and credit/criminal background checks, I also put weight on some components that are more subjective in nature. 

Are you obtaining an inspection, an appraisal, a survey, environmental report etc.? 

It’s important to underwrite using your own projected expenses (hopefully you can at least get utilities/ opex from the seller then calculate capex by looking at the age and condition of major components, cost to replace divided by expected hold period).

Environmental health indicated that the septic tanks are 4/6 1987 and 2/6 2001 but there is sewer to fall back on

An added component to think about is the forced appreciation/ARV of the home, this "bonus value" will be calculated into the refinance when you do decide to. 

In order to control that you need to know the remaining life of every component of the property and include that in your financial model: roof, plumbing, HVAC, flooring, kitchens, windows, siding etc etc In light of this you really need a home inspection, and it better be a really good inspector (many are not) not only to identify present issues, but also to understand your anticipated expenses over the next years.

Once you have two full time incomes, you can move into a different property, maybe a multi-family property, and grow your portfolio.I think a big component of finding a primary home is you want it to be a nice home.

If you're out of state or less knowledgable about this component, it will be very tough to verify good work vs bad until it's too late.A GC costs more, but if they're good at their job, it's worth it!