COLUMBIA, NEW HAMPSHIRE · COÖS COUNTY

BUILD AN ADU IN COLUMBIA.

✓ Allowed by-right · RSA 674:71-73

New Hampshire's HB 577 lets you add one accessory dwelling unit on your single-family lot in Columbia — by-right. A detached ADU can be up to 950 sf, and ADU setbacks match your lot's single-family setbacks.

Columbia setback reference

ADU setbacks in Columbia follow your lot's single-family setbacks for its zoning district. Scan your address in the visualizer and we'll pull your exact parcel and confirm Columbia's front, side, and rear requirements — or just ask us.

Note: Columbia is beyond ~1 hour from our Madbury home base, so a travel-time allowance may be added — we'll spell it out in your quote.

Confirm your zoning

Columbia zoning ordinance ↗NH GRANIT GIS (parcels & zoning) ↗

📍 SEE AN ADU ON YOUR COLUMBIA LOT →GET A QUOTE

Columbia ADU FAQ

Can I build an ADU in Columbia, NH?

Yes. Under NH RSA 674:71-73 (HB 577), one accessory dwelling unit is allowed by-right on single-family lots statewide, including Columbia (Coös County). A detached ADU can be up to 950 sf.

What are the ADU setbacks in Columbia?

ADU setbacks in Columbia match your lot's single-family setbacks for its zoning district. We pull your exact parcel and confirm Columbia's requirements before locking your price.