I am a new construction and remodeling contractor.
I do plans, but only for my own projects.
Have you verified with your building department that this will get approved? Sometimes these things look straightforward but are not. If you don’t know already make sure that the project won’t encroach on any setbacks or easements.
Is the architectural style unique or pretty standard? The roof framing/roofing material replacement and interior and exterior finish work are a few of the biggest variables. I am assuming the lot is flat and no unusual soils problems exist? If the window and door openings cover a very large portion of the wall, such that the job presents structural steel or other non-prescriptive design elements, that could affect the cost significantly.
Have you considered interviewing a few drafts-persons and getting plans first? The design/ build people are possibly overbidding to cover any surprises that might come up. I think you would save money and perhaps some trouble having approved plans to bid out.At the least, you could be more confident that you are not getting taken for some simple job. If you go this route, think about a deadline sensitive pay schedule. Maybe a small retainer, half of the remainder after submittal(to be accomplished in a contracted timeframe) and the rest at approval.If you do this, make sure to go to the building department and ask what the approximate plan check duration would be for a well prepared set of plans for a small addition. Turn around should be pretty quick right now.
