Custom-built Cape home exterior with dormers and two-car garage — new construction by J&M Contracting in Barrington, NH

Built Once. Built Right.

J&M Contracting is a full-service general contractor serving homeowners across New Hampshire and Massachusetts. We manage every detail of your project — from initial planning through final walkthrough.

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5-Star Rated on GoogleWe respond to every quote request within one business day.

Full Project Oversight
Licensed & Insured
Serving NH & MA

What We Do for Homeowners in NH and MA

Remodels, additions, decks, roofing, siding, and custom builds — managed from start to finish.

Custom kitchen with large center island, pendant lighting, and stainless appliances

Kitchen & Bath Remodels

Transform your kitchen or bathroom with expert design coordination and quality craftsmanship.

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Dining room added onto a Dover, NH home, with shiplap ceiling, custom built-in bench seating, and an open view through to the kitchen

Additions & Expansions

Add space to your home with seamless structural additions managed from permits to finish.

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Finished composite deck with bench seating beside a cottage's blue back door, golden afternoon light

Decks & Patios

Composite and pressure-treated decks built to last — ground-level, side-entry, and multi-level, with the framing done right underneath.

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Renovated mudroom with new exterior door, custom built-ins, and refinished ceiling

Full Home Renovations

Complete whole-home transformations with phased project management and minimal disruption.

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Front exterior of a custom-built colonial with navy siding, white trim, and attached two-car garage

New Construction / Custom Homes

Custom homes and detached ADUs built from the ground up, with full project management at every stage.

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Attached two-car garage on a custom home built by J&M Contracting in Barrington, NH

ADUs & Accessory Buildings

In-law suites, detached ADUs, pool houses, garages, and outbuildings — permitted, built to code, and managed like any other build.

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Granite entry steps and paver walkway installation, Newburyport MA

Exterior & Hardscape

Siding and exterior repair, paver walkways, granite steps, and patios — the outside of your house, built to last through New England winters.

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Front elevation of a yellow colonial in Kingston, NH with a new Dual Black asphalt shingle roof

Roofing

Full tear-off and asphalt shingle replacement, managed start to finish - most homes done in a single day.

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Recent Projects Across NH + MA

Browse recent projects from across New Hampshire and Massachusetts.

Finished dining room with shiplap ceiling, custom built-in bench seating, dining table, pendant light, and open view through to the kitchen

Dining Room Addition & Open-Concept Renovation

Dover, NH

Long view of the finished mudroom — built-in bench with brass hooks on the left, new 9-lite exterior door at the back, and built-in desk with cabinets on the right

Mudroom Renovation & Custom Built-Ins

Newburyport, MA

Finished side-entry composite deck styled with woven chairs, side table, planters of flowers, and a dog resting in the corner

Side Entry Deck Build

Merrimac, MA

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“J&M Contracting did a whole home renovation and got us moved into our beautiful new home in NH. They made a big undertaking feel stress free and did an amazing job. J&M coordinated the full scope of work including new kitchen, bathroom, windows, doors, flooring, drywall, lighting, and painting. They listened to our needs and delivered the work. Could not be happier with J&M Contracting — would highly recommend.”

Casey D.

Barrington, NH · Full Home Renovation · October 2025

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