Expect a custom ADU to take 9–18 months, with 3–6 months for design and permitting and 6–12 months for construction, depending on complexity and contractor availability, and the speed of processing permits.

While we faced minor delays with contractor scheduling, strong project management minimized impact.

Hire an HVAC contractor to go check it out, of course. 

So when you need to go check on things, rent units, meet contractors, etc, you're jumping in the car for 6 hours, spending 1hr there, and I'm thinking after a full days's work. 

Hey @Chi Lo - I actually have a video on my YouTube page about this (lookup ClosedByMo on YouTube).Regarding walls being damp and waterproofed, it means there needs to be waterproofing on the basement retainer walls (this is something you can do post-construction and the contractors would need to dig around the house exposing the basement/foundation to apply the waterproofing). 

Quote from @Kody Smith: without getting too deep into my finances, what my strategy is...1. take loans to buy properties (leverage)2. fix/flip for day to day cash flow income3. use some of the fix/flip income to buy consistent cash flow through:- business acquisition, - commercial properties (MF and store fronts),I have no intention of doing ALL of the management myself, I will hire management as needed (medium term goal)my expected core role is money provider, evaluating the numbers, making decisions, and connecting with investors, wholesalers, lenders, contractors, and property owners.while I am just on step 2 of the journey, I am looking toward step 3 to stabilize, and not worry about if house prices drop mid project or not (or not worry as much) So to be fair this is more about obtaining and growing a real estate business not simply buying rentals for cashflow.

In a city like Philly, you will face many challenges - you need to learn the market and know the neighborhood and the block and make sure all of your numbers are within reason, you need very reliable contractors, you need a to understand the permit process, you need to be familiar with market expectations. 

---FYI: licensed contractors in our area charge $95-$125/hour.

If there are changes you want to make then send your tenants official notice of those changes via in person delivery or certified and regular mail along with a copy of the new lease.

@Dani Murai, while I can't give you a name of anyone in your area (I am not from there), when you are interviewing contractors, here are a couple things I have seen:I avoid any contractor that has a draw schedule based on percentages, i.e. 1/3 up front, 1/3 at halfway completed and 1/3 at completion.