I have a space on the 4th floor/attic of my 3-family and im looking to take advantage of the ADU program that Boston offers. The unit would add probably 600-800 sqf more and has 2 separate entrances with appropriate ceiling height.

Looking for any information/tips from anyone who has used this program or has any knowledge of it. Have no idea where to start but I assume an architect is the first step. Any info on costs or tips on applying for permits or anything would be helpful.