If it was an accident-storm, crack in foundation, etc, I would do the regular checks and rent to them provided you are fine with the pets.

@Terri-Leigh H.the hot tub is similar, bench style, to what is found at ski resort hotels.

@Nicholas Schwab You have the beginning of what could be a really interesting tax strategy.

It's good to put together a long-term plan, but I have never understood how someone with 0 properties is more worried about how to scale then how to build the foundation correctly.You are putting the cart before the horse.

Porch floor, painted foundation exterior, bathroom ceiling.

It could be an easy fix like this or a bigger problem depending on the factors at play (are the joists accessible, will it mess anything else up if you just jack it up and reinforce, is there water damage or structural damage to the foundation causing the sag instead of just old joists, anything else going on like a supporting wall or posts under the floor, wiring or plumbing runs involved etc.).

Time to build the foundation below.Check out the Start Here page http://www.biggerpockets.com/starthere Check out BiggerPockets Ultimate Beginner's Guide - A fantastic free book that walks through many of the key topics of real estate investing.Check out the free BiggerPockets Podcast - A weekly podcast with interviews and a ton of great advice.

If you have specific concerns, for example foundations concerns, you can get specialized foundation inspector.

the challenges with flips  is that there are so many angles to try and cover / consider that it is somewhat like spokes on a wheel… even if you just take it system by system… roof, plumbing, AC, foundation, subfloors, electrical, appliances, septic, materials expenses, holding costs, taxes, etc.  

You don't need to know everything to get started; you need a foundation to build on and the rest will come through experience and then refining your education.You can build a basic understanding of investing in 3-6 months.