While they are legal from a building department view point, if there are complaints from neighbors about you renting it long term, it could create issues with zoning.  

We meet monthly in Long Beach with panels or presentations from other investors, or affiliated professionals like attorneys, managers, contractors, insurance brokers, etc....Check it out.

The only people who benefit are the long term tenants which ultimately hurts investment in the area.  

A year in and lots of progress made but still a long way to go.

Can they prove how long it takes to rent a vacant property?

We have great long term residents in our POH rentals and do very well financially with them. 

Long-term goals could involve building a diverse portfolio, achieving financial independence, or even transitioning into real estate full-time.Ultimately, the journey in real estate investing is both challenging and rewarding.

Check for how long the current tenants have been in the property and assess the property condition.

This means that as long as the sellers’ title is vested correctly then I should be clear to deliver a warranty deed when the borrower completes their end of the CFD agreement.

Estimating construction and remodeling has been around a long time, people who do this are called estimators.There's books, software and even courses on estimating.