Southern New Hampshire spans Keene to Portsmouth. I imagine the prices in Keene are quite different from Portsmouth. What part are you interested in?

Between exit 1 and 5 off of rt 93. Thanks 🙏

What level of build are you looking for? Budget build or custom, high end everything. It very much varies.

300$

I’d like to know the budget price…trying to build an ADU for aging parents. It should match the quality of my existing home, though, which is B- grade according to my vision property card.

That seems really high, I’ve had designers/architects say it’s closer to $225 sq ft but looking for someone with an actual recent experience to get a realistic ball park. Can I ask what you’re basing that off? Thanks

With custom builds price per foot is really hard to nail down. Depends on design, size, build quality, paints, tiling, extra features, etc. Source: built a house & closed March 2020. Out of pocket cost then was $770k for ~2400 sq. ft. Was ~$25k to finish 300 sq. Ft. Room over the garage in late 2020. House appraised for just over $1m in June 2022. Personal preferences on something like that throws any form of standard cost out the window.

$300/sq ft seems to be about the going rate, maybe even higher. I had a 300 sq ft addition done right before pandemic and nearly every quote was over $100k.

Thanks, what quality would you say you went with? Was it pretty high end or middle of the road?

I’m looking to build an ADU with middle of the road materials, no crazy design. 650-800sf…

Middle or below. I did a fair amount of additional work myself to save cost.

Totally appreciate that. The cost of materials is so out of whack these days, I’d honestly just talk to a good builder up front to get the best info. I had a fantastic experience with JDL Building out of Greenland.

Thanks, are you generally in the same area I described? Off of rt 93 south of Manchester? Or in another part of the state? Just trying to get as close of an apples to apples comparison as possible.

Way too many variables. You're going to have to talk to some builders and get some guesstimates.

I'm having a 1400 sq ft + 830 sq ft garage built in NW NH. Not including land, I'm 330K into it(with most materials purchased). About 100K of that is dirt work, and the dirt work isn't done yet.

Southern NH, yes.

So the actual building itself is going to cost you $230k? I’m expecting site work to be its own cost, not built into the price per sq foot…the architects/designers I’ve talked to so far we’re saying 200-250/sq which includes all the building materials and finishes and the excavation for the foundation (and the foundation itself) and systems…hope that reduces the variables but yeah I get that it can vary widely. Thanks for the data point.

Thanks, I’ll check them out.

Did you go through with the build or just get a quote? Did you get more than one quote btw?

We are finishing our third floor. Requires a dormer. 75p sq ft for $195k

Like others have said, $300 is a good target. Contractors are going to give you a better idea of budget. Architects and designers are good at what they do, which is design. Don’t let an architect be your estimator

Oh it's going to be much more. Appliances, painting, plumbing, electric, labor, etc is all going to push the cost up.

Not to mention the well that still needs drilling.

Is it not possible to use the same well that we already have?

Dumb question but how do you get a builder to estimate the cost of the build if you haven’t already had full plans drawn up by a designer or architect? All the builders I called asked me is I had building plans, which I don’t. Which is also why I’m trying to gather more info (albeit somewhat generic) so I know what to tell the designers to design…

Not a dumb question. Start with the truth. “I’m trying to gather more info to determine if I can move forward with this project.” Then after describing what you’re thinking, ask them if they’d be willing to share what level of finish and what the $/sf was on there last few projects.

Thanks yeah, I called a few builders about a year ago when I first started my research but I basically got the impression that they were all so slammed and didn’t seem to want to even waste their time with someone who didn’t already have plans in hand. Maybe that has changed or maybe there are builders who aren’t as busy but that is how I started—I called builders first and they all told me I needed plans for them to give me a meaningful estimate. Maybe I need to think outside the box, not sure what that entails but I need to build something for my aging parents and custom design/build is really all I can think of. All this feedback is much appreciated.

You should be fine there. Good luck on your project.

$275-315

Follow up question: can a builder or someone knowledgeable about this stuff give me a rough break down (in percentages) of where the ~$300/sf gets spent on a new design/build? Like is it 10% for the foundation, 40% for the framing/shell, 30% finishes and 20% systems for heating/cooling/electric? Or are there any basic rules that apply here? Just curious as to where the money goes so I can maybe save money by doing some of it by myself or doing it in stages.

A rough estimate is $225-$300/SF but like others have said, it varies based on site conditions, design, and finishes.

My company specializes in ADU design and planning. We can provide preliminary estimates based on your project scope and help you with bidding the project out to local contractors to get the best value.

You can check us out at Buildoly - we are a New England based ADU platform that helps homeowners design, permit, and build custom ADUs in one streamlined process. If you send me a message, I'd be happy to provide a free feasibility report & cost estimate on your intended property. You can also sign up for a consultation and we'll guide you through the entire process and provide insights specific to your ADU build.

Thanks, I’ll dm you 🙏

No problem!