Drafter for Residential Additions

We are adding two things to an existing 1990s residence. 1. A new front entry approximately 10' x 15' that will be added to the existing structure. 2. A new "great room" approximately 25'x 30' that will be added to the back of the existing structure. We are hoping to minimize invasiveness to the existing structure (basically pop on an entry and a great room). We have sketches of this and know exactly what we want it to look like. We have done TONS of remodeling and have a very capable contractor waiting to start. We do need a permit and we need help with the permitting process. We do need this process started ASAP. THANKS!