Premium ADU Builder in Massachusetts
Custom Accessory Dwelling Units Designed and Built for Massachusetts Homes
An accessory dwelling unit is more than an additional room—it is a fully integrated living space designed to expand the possibilities of your property. Provost Companies is a premier ADU builder in Massachusetts, providing comprehensive design, planning, permitting, construction, and finishing services for homeowners throughout the state.
What is an ADU?
An Accessory Dwelling Unit is a secondary residential unit on your property. ADUs can be attached to your home, stand-alone, or built over a garage, offering versatile living solutions while preserving your lot’s character and zoning compliance. Unlock your property’s potential with a custom Accessory Dwelling Unit from Provost Companies. Contact us today for a consultation and let’s design the perfect space for your needs.
Our ADU Services Include:
Building an ADU requires more than simply adding square footage. The best results come from careful planning that considers the property, existing home, site conditions, utilities, structural requirements, local regulations, and how the space will ultimately be used.
- ADU Design & Planning
- Detached ADU Construction
- Attached ADUs & Home Additions
- In-Law Suites
- Basement ADUs
- Garage Conversions & Garage ADUs
- First-Floor ADUs
- ADU Permitting & Pre-Construction
- Structural Modifications
- Plumbing, Electrical & HVAC Coordination
- Interior & Exterior Finishes
- Complete Design-Build ADU Construction
Provost Companies provides a comprehensive approach to ADU construction, coordinating the many moving parts of the project through a single experienced team. Our construction professionals can help evaluate your property, develop a practical design, navigate permitting and approvals, coordinate trades and materials, and oversee construction through completion.
Types of ADUs We Build in Massachusetts

Detached ADUs
A detached ADU is a fully independent living space built separately from the primary residence. Often designed as a backyard cottage or small guest house, detached ADUs offer excellent privacy and flexibility while allowing homeowners to create a completely customized living environment that complements the existing property.

Attached ADU Additions
An attached ADU is built as an addition to the primary residence, creating a separate living space while sharing a wall or other structural connection with the main home. This approach can make efficient use of the property while providing an independent kitchen, bathroom, living space, and entrance.

Garage Conversion ADUs
An existing garage can often be transformed into a comfortable, fully equipped ADU without constructing an entirely new building. We can reimagine underutilized garage space as a private apartment, guest suite, or independent living area while addressing the structural, mechanical, insulation, and interior requirements of a residential conversion.

Above-Garage ADUs
Building an ADU above a garage creates living space without requiring additional ground-level footprint. Whether incorporated into a new garage or added as part of a larger construction project, an above-garage ADU can provide a private apartment, guest suite, or multigenerational living space while making efficient use of the property.

Interior Basement ADUs
A basement can provide an excellent opportunity for an ADU when existing conditions allow. We transform underutilized lower-level space into a comfortable, independent residence with living areas, bedrooms, kitchens, bathrooms, dedicated entrances, and the necessary upgrades for safe and efficient residential use.

Interior Upper-Level ADUs
Unused or underutilized upper-level space can sometimes be converted into a private ADU without expanding the home's footprint. Attic and upper-floor conversions can create a separate living environment while taking advantage of existing structure and utilities, making them an appealing option for properties where an exterior addition isn't ideal.

First-Floor & In-Law Suite ADUs
A first-floor ADU can be an especially practical solution for aging parents, caregivers, adult children, or anyone who benefits from convenient, stair-free living. These spaces can be designed as accessible in-law suites with their own living areas, kitchens, bathrooms, bedrooms, and entrances while remaining connected to the main home.
ADU Information and Resources
Why Choose Provost as Your Massachusetts ADU Builder?
With Massachusetts ADU regulations evolving and more homeowners exploring the potential of accessory dwelling units, choosing the right builder is an important first step. Provost Companies combines construction experience, project management, design-build capabilities, and local knowledge to deliver ADUs that are built around the property, the homeowner, and the intended use of the space.







