My only challenge was a 1 month delay in construction because the units in this building (1975 high-rise construction) didn't have individual water shut off valves, so in order to do plumbing work, we had to wait for the building to shut down water to the entire tower.

Also, does anyone have thoughts on using a home inspector vs. hiring inspectors based on specialty (plumbing, roofing, etc.)?

Building a budget: Roof, electrical, exterior siding/paint, gutters, plumbing, heat, flooring, kitchen, bathroom, paint. 

Hey Kayla,As @Ned Carey stated, by adding all of these additional rooms and running plumbing & electrical himself, you are putting yourself at a huge risk.

Unfortunately, we are now in the midst of the COVID-19 pandemic and leasing is very slow but we do get the first few residents set up in their new apartment homesJuly 2020: Community is 95% occupied with average rents at $675/month (range from $613 - $735)Rehabilitation included: Rebranding and signage, exterior pavement and concrete, fencing around the community, restoration of the brick and masonry, weatherproofing, gutter and roof repair, landscaping and lawn care, security surveillance, interior renovations included new flooring, paint, appliances, sinks and countertops, low flow facuets, repairs to the plumbing and electrical systems, new water heater. 

Purchase price: $47,500 Cash invested: $37,500 A tri-plex we purchased from what I would politely call a slumlord, over the course of 2 years we gutted and renovated a 2 bedroom unit, completely rewired, re-plumbed, and redesigned the other two 1 bedroom units.

Homeowners can pull building permits and then Electrical Plumbing Mechanical need to pull their own permits because they have their own licenses

New electric, plumbing, and heating systems were added, and cosmetic updates like new flooring, cabinets, and paint.

New plumbing, new tile, new AC unit.

The last five years has been a cluster f of naive, inexperienced, poorly capitalized and unprepared wanna be real estate investors ( feeling fully “empowered” by obtaining information via books, video, on line websites, seminars, etc) buying properties that can’t possibly cash flow positively, especially in the long run when worn systems, such as HVAC systems, roofs, plumbing, electrical will need to be replaced or upgraded.