If it seems to make sense, then I will visit the property take pics, measurements, etc.

Don't be discouraged and keep testing and measuring your responses.

The appraisal had 1531 sq ft listed (this included a detailed listing of how it was calculated with all the measurements).  

Modular, Manufactured- for comparable stick home, the quality for both is superior, as fewer/no  mistakes are going to be made in measurement, cutting, etc.

In particular, the cap rate should be considered as a measure of risk and NOT solely as a measure of return (when acquiring). 

It wouldn't make sense in a house like this unless you were gutting it imo though Not sure why this would have been directed to me - I suggested he submeter due to his earlier post stating that he could not do that until the lease was up; the lease probably says landlord pays water, but that does not limit the landlord from measuring consumption by submetering - it just means that he can't present a water bill to the tenant.

This way you'll be able to measure if your equity is work for you or not or if you'd be better off doing something else with it.

I have over 10 years of experience making mistakes, developing solutions, and implementing preventative measures to ensure these risks are minimized.The more experience I gain, the more I see that one of the most essential components of real estate investing is risk management, but also property management, people management, market research, investment analysis are also essential (not in order of priority).Some specifics:My tenants (customers) are new families with 1-3 children. 

I will give them lockbox combo to get detailed measurements as they might need to do.

I agree with hakchinoy, there are multiple security measures that must be taken into consideration by using your own site.