In 2023, gross ROI for flips averaged 27.5%, but net ROI (after all costs) is usually 10-20%, calculated on the total investment (purchase price + repairs). 

So, they could also force the municipality to pay them some profit that way as well since those sales usually go for more than you might think is market rate.

how long does it usually take?

There is also usually a map of the ongoing and finished developments.

You will usually have about 6-8% of what you purchased the property for in taxes you won't have to pay in the first year or few years.

Usually EMD is submitted with a title company that way you are not physically handling cash @Luis Herna

We used a service and a proven letter, I mailed every month for 6 months, actually alternating 500 every two weeks, so I had more time to follow up with the usually 30-ish responses. 

Normally there is some sort of onboarding or start up costs however usually PMs charge based on how much revenue they received hence if no revenue is produced due to the property being vacant, no funds are collected.

Prepayment penalties- usually 1-5 year terms.

@Fahima Hilal an architect usually only outlines mechanicals, plumbing & electrical on their blueprints.Your contracts should be creating appropriate drawings showing where their stuff would go and submit to city with their permit application.