ADU Design in Lebanon, NH
Torch Engineering provides accessory dwelling unit design and permitting for projects in Lebanon, New Hampshire. Projects in Lebanon are served by our Concord team — same engineers, same permit-ready drawings, anywhere in New Hampshire.
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ADU Design in New Hampshire: what governs your project
New Hampshire's 2017 law (RSA 674:71 through 674:73) requires every municipality to allow at least one attached accessory dwelling unit by right wherever single-family homes are permitted. Municipalities may still regulate size, aesthetics, and separate entrances, but they cannot ban ADUs outright.
Energy code
Local rules typically cap the ADU at a fraction of the primary home's size, may require owner occupancy of one unit, and use the standard residential building-permit path. Sewer and water connections follow the local utility's normal process.
Permitting & plan check
Permitting is municipal, handled by planning boards and building departments in each city and town. There is no broad state building-permit layer, but NHDES wetlands and shoreland reviews run alongside local approvals for affected sites.
Good to know
- New Hampshire's Shoreland Water Quality Protection Act regulates development within 250 feet of public waters.
- Mount Washington has recorded some of the highest surface wind speeds ever observed on Earth.
- New Hampshire levies no general sales tax and no tax on wage income, which shapes commercial development economics.
Every discipline, one team
MEP Engineering in Lebanon
mechanical, electrical, and plumbing design — permit-ready drawings, best price.
Structural Engineering in Lebanon
structural design, analysis, and PE stamping — permit-ready drawings, best price.
Civil Engineering in Lebanon
site civil engineering and land development — permit-ready drawings, best price.
PE Stamping in Lebanon
licensed professional engineer stamping — permit-ready drawings, best price.