The property may have specific costs.
Closer to the water, historic district, personal choice of quality of materials, quality of the builder, experience of the builder, and possibly the town and area within the town will all affect the per foot cost.
Averages are only for statistical news reports.
I would choose a builder or two with finished projects that you like and interview them for costs, schedule, etc.
Everything else is guessing.
(Please note: when you choose an answer as a Best Answer, or at least give a thumbs up, it helps those who answer questions here.)
I am in cost shock. Minimal costs on Cape Cod being given to me by reputable contractors are $275-$300 sq ft. new construction minimum. Your taste in trimmings/appliances etc. determines the plus factor.
I am also doing a project in Montana and have done projects in Connecticut in the country and in the city including historic district. Montana is $150,00 sq foot and in CT the Northern corner is a lot less than in Hartford or New Haven. Codes influence costs. Cape Cod is highly regulated. Building is now to the standards of a super hurricane coming through. Old house renovations are no longer a labor of love, but one for someone with extremely deep pockets. Tearing down is cheaper than renovating. What a shame. Good bye "Old Cape Cod".
The work I have done in historic districts is confining and super expensive as well as fire districts in cities.
Do your homework ALWAYS. I had 3 plain wooden steps to build off my porch on Cape Cod. I called 2 handymen advertised in the local paper. The first bid was $2,800!!!! The 2nd bid $600.
The steps in fact were worth only about $250.
Even amongst reputable builders there may be a huge difference in bid. The first bid I got was $60,000, the 2nd $12,000 and the 3rd $10,000 which turned into $12,000 when we discovered we needed to plywood the roof before re-shingling - not evident before the shingles were removed.
I decided a recent renovation was not that involved and wanted to hire builders at an hourly rate as opposed to getting a bid. All was well, they got on my calendar in May to show up in September. They never showed up. Scrambling to replace to keep on schedule, and now the contractors bidding know they have me by the !(&$&&@)(!!! Lesson learned.
One of the biggest problems of today's pricing is comparing it to building one has done years ago. I put on a whole 2nd floor of a house in the 1990s for $25,000. It was gorgeous. Today $25,000 might buy me part of a bathroom. Also back when I could climb ladders and tackle saws, hammers, etc. I did a lot of stuff myself. ($0) Funny how replacing yourself is sooooo expensive.
Good luck all you renovators - new house builders. Go for your dreams but have a fall back plan in case it breaks the bank. - Nancy T-V