The best additions don't look like additions. Dihedral Builders is a Sandpoint home addition contractor that ties new construction into your existing home so cleanly that visitors can't find the seam.
An addition is half new construction, half surgery on an existing building — and the surgery is the hard part. Matching rooflines, foundations, floor heights, siding profiles, and trim so the new work reads as original takes a builder who has done it many times. Chad Gailey has spent about twenty years doing exactly this across the Pacific Northwest, including additions to older homes where the match had to be convincing up close.
Dihedral Builders now works from a permanent office in Sandpoint, and home additions Sandpoint homeowners actually need — a primary suite, a bigger kitchen wing, a garage with living space above, an ADU for family or rental income — are squarely in our wheelhouse. Our completed addition work is in Washington, and we say so; the craft transfers.
We run additions design/build: our preferred designers and engineers work out the structure and the match up front, we handle permits, and you deal with one person from the first sketch to the last coat of paint.
Primary suites, family rooms, and expanded kitchens built out from the existing footprint. We tie the foundation, framing, and roofline into the original structure so the addition performs and reads as one house.
Going up instead of out when the lot is tight. These are engineering-heavy projects — the existing structure has to carry the new load — and we plan them with engineers before anyone falls in love with a floor plan.
Detached and attached accessory dwellings, garages with storage or living space above, and shops. Useful square footage for family, guests, or rental income, permitted and built to the same standard as the main house.
The first question for any Sandpoint addition is where the property lines and setbacks actually sit. Inside city limits, the City of Sandpoint's zoning sets setbacks, lot coverage, and height limits that decide whether you build out, up, or not at all; outside town, Bonner County's rules apply, and waterfront properties near Lake Pend Oreille bring their own shoreline considerations. We sort out what the parcel allows before design starts, because an addition drawn for a spot you can't build in is wasted money.
The second question is structure. New work in the Panhandle gets engineered for Bonner County snow loads, and when an addition ties into an older roof, the connection point — valleys, step flashing, where two roof planes shed snow into each other — is where careless work fails. We design the tie-in so snow and meltwater have somewhere to go, and so the older structure isn't asked to carry loads it was never built for.
Then there's the match. Much of the housing stock here dates from the 70s through the 90s, and lumber dimensions, siding profiles, and window styles have all changed since. Making a 2020s addition look native to a 1980s house takes deliberate choices — matching or intentionally complementing rooflines, aligning floor and ceiling heights, sourcing siding that takes the same shadow line. On rural parcels, we also confirm septic capacity early if the addition adds bedrooms or baths, since that can shape the design more than the floor plan does.
Dihedral Builders recently did a room addition to our house. Chad came out to take measurements and to put together an estimate. Their estimate came in the middle of our other estimates. What made us decide to go with Dihedral Builders instead of the other contractors was the personal service that we received. Most of the other builders emailed us the estimate. Chad made an appointment to go over the estimate himself and answer any questions that we might have had. After getting all of the bids in and deciding on hiring Dihedral Builders we received a schedule of work. Dihedral Builders kept to the schedule and to our budget. Chad was very easy to reach and returned all calls and emails before, during and after the build.
Darby Darrow · Yelp review
Such a great experience working with Chad and his team. They are true craftsmen and stand by their work. They helped us design and replace a huge multistory deck, and were helpful and responsive throughout the process. We will definitely be using them again on future projects, outstanding quality and service.
Sarah A. · Yelp review
Yes. Additions require building permits — through the City of Sandpoint for in-town properties or Bonner County for parcels outside city limits — and zoning rules on setbacks, lot coverage, and height determine what you can build where. Dihedral Builders researches what your parcel allows before design begins and manages the permit process through final inspection.
It should, and that's the standard Dihedral Builders works to. Matching an addition to an existing home means aligning rooflines, floor heights, siding profiles, and trim details — harder on older homes because materials have changed over the decades. We plan the match during design rather than improvising it during construction.
Only an engineer can say for certain, which is why Dihedral Builders involves one before design gets far. The existing foundation and framing have to carry the new loads, and in Bonner County that includes serious snow loads on the new roof. If the structure needs reinforcement, it's far better to know that at the planning stage than mid-build.
It can. Septic systems around Sagle, Dover, and the Selle Valley are rated for a certain capacity, and adding bedrooms or bathrooms may exceed it or trigger permitting requirements. Dihedral Builders checks septic capacity early in planning for rural additions so the design fits what the property can support.
If your home is right but too small, an addition may beat moving. Call (208) 714-0250 and we'll look at what your property allows.
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