Footage with room for more is always a good idea.

Flipping was good for awhile, but I hear those margins are super tight right now unless you're doing major development (adding square footage, bedrooms, bathrooms, etc.) ... that means higher renovation costs and longer hold times (not in a good way as a cash flow positive rental), so not my cup of tea.

.: ___________________________________FILE INFORMATIONPROPERTY ADDRESS___________________________________________ ______________________LEGAL DESCRIPTION __________________________________________________ ______________TAX ASSESSMENT ___________________________ TAX APPRAISAL _______________________YEAR BUILT_________________________________ SQUARE FOOTAGE ____________________ATTORNEY _________________________________ PHONE ________________________________BALANCE OWING ____________________________ LAST PAYMENT _______________________ORIG.

What square footage?  

I've hiked all of NH's 4,000' Mts., then went on to do all of New England's, but that was years ago, in my youth (late 40's). 

It's more like additional rooms, additional square footage like finishing a basement, adding things that would increase value like extra bathroom.

If there is no window, then a bath fan must be installed and properly vented.I am not familiar with your square footage, or local codes,  but looking at your numbers compared to my exposure, you under budgeted.

I just want a much more systematic and AUTOmatic way to quickly assess repair costs on a property given square footage, # of bed/bathrooms, size of kitchen, size of yard, area of roofing, etc.My question to anyone out there: is there any tool available that will do this quickly and accurately (within +/-10%)?

For water, I'd base it on number of people living there, for electricity, base it on number of bedrooms or square footage. 

Common equations to determine billing that we use are as follows:Ratio based on Square footage: = Bill total * (Unit Square Footage / Total Square footage)Example: Unit 1 has 1000 Sqft, Unit 2 (garage) has 500 sqft.