Guiding Builders specializes in ADU construction, offering design, permitting, and building services. Projects include detached ADUs, garage conversions, in-law suites, granny flats, and casitas—custom-built to add value and living space.
read more
Mass ADU is a Massachusetts-based ADU contractor offering full-service accessory dwelling unit construction. Services include free consultations, permitting, design, and build. They serve homeowners statewide with a clear 3-step process.
read more
Massachusetts ADUs are now legal by right statewide after 2024 legislation. MBA Builders offers full-service ADU construction across Greater Boston, with structured preconstruction planning and builds starting around $450/sq ft.
read more
Trust Contractors designs and builds ADUs, including detached units, garage conversions, basement ADUs, and in-law suites. Services cover zoning, permits, and construction, helping homeowners add rental income, family housing, or flexible living space.
read more
Acorn Deck House builds luxury prefab ADUs in MA, featuring exposed beams & large windows. Options include 900 sq ft & 730 sq ft models. ADUs boost property value by 25–34% & generate rental income.
read more
River City Construction is a Boston-based ADU contractor specializing in home additions, garage conversions, in-law suites & detached backyard cottages. They manage design, permitting & full construction under one roof.
read more
FiveTen Construction & Design is a Massachusetts ADU contractor offering design, permitting, and construction services. They build detached, attached, basement, and garage ADUs, ensuring full compliance with MA building codes and zoning regulations.
read more
Post Woodworking builds custom Accessory Dwelling Units (ADUs), including detached ADUs and in-law suites. They offer flexible involvement, from full construction management to building only, ensuring seamless integration with your existing home.
read more
North Shore ADU Home Builders LLC builds custom ADUs up to 900 sq ft across Massachusetts. Services cover design, permits & construction. Rental income ranges $1,800–$3,500/month. Property values may rise $100K–$250K.
read more
Turkel Design offers custom-designed accessory dwelling units (ADUs) using a prefab process. Highlights include expert cabinetry, smart storage, and high-quality finishes, ensuring ADUs feel purposeful and cohesive with the main residence.
read more
Patco Homes offers full-service ADU construction, managing feasibility, design, permits, and build. Ideal for granny flats, in-law suites, or detached ADUs, they guide homeowners through every step with one dedicated team.
read more
Allan Tran's Exterior Finish Work (AJT Properties) specializes in residential exterior services including deck construction, porch railing installation, storage structures, and CertainTeed siding. Known for reliable communication, on-budget delivery, and durable craftsmanship.
read more
Pro's Edge Small Homes is a licensed ADU contractor in MA & NH with 20+ years experience. They offer turnkey design, permitting & modular construction of granny flats, in-law suites & backyard cottages, including a free property evaluation.
read more
Landform Build is a Portland, Maine design-build firm specializing in infill development, ADUs, and residential projects. Services include zoning analysis, architectural design, feasibility studies, permitting support, and general contracting for accessory dwelling units and multi-family housing.
read more
Top-Pro Construction, Inc. is Greater Boston's trusted ADU builder with 25 years of experience. Specializing in detached ADUs, attached units, garage conversions & basement ADUs to boost property value and rental income.
read morePortsmouth, New Hampshire is one of the oldest cities in the United States, founded in 1623 along the Piscataqua River. This rich history means that many neighborhoods feature historic homes and protected districts, which creates unique challenges for ADU contractors working in the area. If you are considering adding an Accessory Dwelling Unit to your Portsmouth property, working with experienced local ADU contractors who understand the city's specific zoning codes, historic preservation guidelines, and building regulations is absolutely essential.
Portsmouth has made efforts to encourage ADU development as part of addressing the region's housing needs. Under Portsmouth's zoning ordinance, ADUs are permitted in most residential zones, including single-family and multi-family districts. However, there are important rules that your ADU contractor must navigate carefully:
A significant portion of Portsmouth's residential properties fall within or near designated historic districts, such as the Strawbery Banke neighborhood. ADU contractors working in these areas must obtain a Certificate of Approval from the Historic District Commission before construction can begin. This means that exterior materials, window styles, rooflines, and overall design must be compatible with the historic character of the surrounding neighborhood. Skilled ADU contractors in Portsmouth are familiar with these requirements and can help homeowners design units that satisfy both modern functionality and historic preservation standards.
Hiring a contractor with direct experience in Portsmouth is a significant advantage. Local ADU contractors understand the nuances of working with the Portsmouth Planning Department, the Building Division, and the Historic District Commission. They are also familiar with the city's infrastructure, including older utility connections and foundation types common in New England homes, which can affect ADU construction costs and timelines.
Whether you are planning a garage conversion, basement ADU, or a new detached backyard cottage, working with qualified ADU contractors in Portsmouth, NH ensures your project meets all local codes and historic guidelines while maximizing your investment.