. - Carriage House needs a lot of work to convert buuut has a modern foundation meant for a two story house and roughed in plumbing.- Renos will take 3-4 months unless permits hold us up.- Property is in Kitchener, Ontario, Canada

I'm checking out a HUD home and the Property Condition Report states there is "Plumbing System & Drain System damage."

All houses have indoor plumbing and an outdoor cat*.

So lets start with a Cosmetic rehab-(lets say it includes) Updating everything in the bathrooms, updating everything in the kitchen, new paint, new floors throughout, new trim where needed, new int and ext doors, new light fixtures, drywall repair where needed, new outlets, landscaping clean up, putting in a few new windows, power washing the house, servicing all mechanicals, inspecting all electric and plumbing.Lets go by sqftSingle family:single story houses up to 1500 sqft- about 6-8 weeksSingle story houses 1500sqft-2500sqft- about 8-10 weeks single story houses 2500sqft- 3500 sqft- about 10-12 weeksTwo story house up to 1500sqft- about 7-9 weeks two story house 1500sqft- 2500sqft about 9-11 weekstwo Story house 2500sqft-3500sft about 11-13 weeksMulti Units:2 unit 2000sqft-3000sqft 10 weeks-14 weeks2 unit 3000sqft-4000sqft 14weeks-17weeks3 unit 3000sqft-4500sqft 15weeks-18 weeks4 unit 3000sqft-4500sqft 17weeks- 20weeksNow lets say it was a full gut rehab (all items from cosmetic) plus running all new electric from panel to the outlets, all new hvac forced air or boiler both heat and ac, and new plumbing through out.

As with any new construction, you'll have a year of shakeout where you find things that aren't quite right -- a plumbing leak, a window seal, etc. 

New roof, furnaces, carpet, paint, appliances, mostly new plumbing, etc...What was the outcome?

That would be plumbing, hvac, electrical or structural.

For example the dozens of folks that have guaranteed they will lease my unit with cash in hand "tomorrow", the numerous contractors that have said they will arrive at X time for the emergency plumbing/heating/electrical work, or the tenants who say they'll have the money in by X.

I should not have high expenses considering all systems (HVAC, plumbing, electrica) are new.

Double check.Usually you want 7’ of headroom and 6’4” under plumbing and ducts in main walkways and the main part of the room.