@Al Bigonia  sent me this link which explains the ruling: IRS Eases Repair Regulations for Small Businesses .Thanks, Al.

@Jean Paul Rousseau There are additional regulations that need to be complied with and additional calculations to apply toward credits and such.

Regulated or registered lenders don't have the issues that private investor/lenders have.Financing then goes much deeper than drafting an note that is agreeable between two parties and the unknown, unknowns will determine what may be safe, predatory, intentional, lawful, enforceable or prudent.  

We as general contractors, get normal penalties of $500/day if we are delayed, of course, considering the client is strict on their deadline.

While California has strict laws, they are also great because it is black or white!

Looks like it hasn’t been updated since 2015 unfortunately.I’ve found the city departments mentioned to be less than helpful when it comes to answering questions about regulations and requirements for Airbnb.TJ

Also re licensing - here there are strict guidelines contractors must follow concerning acceptance of payment prior to the rendering of services.

As others have already nailed it, yes, you are responsible.You can call your local building regulations office and ask what is required to meet local code which will also be in compliance with federal and HUD requirements.Stairs should also be uniform where each step has the same rise and run, an exception would be at landings.

I am researching on how I can rent out single family houses by the room but it seems like every single HOA rules and regulations prohibits this.

.- always have strong reserves for repair, factor in everything from tree to fences- make sure your HVAC is caged- when you purchase OOS, make sure you understand the city regulation, is there a permit issue or something like that.