Full-Service ADU Construction
Design. Permits. Build. One Team From Start to Finish.
Keep Family Close
Create a private, fully independent living space for a parent or grandparent without sacrificing privacy.
Create AirBnB Income
Turn unused space into a short-term rental designed for comfort, durability, and long-term returns.
Build for Long-Term Renting
Add a compliant, high-quality rental unit that increases property value and generates consistent monthly income.
Get A Free Quote For Your ADU
Why Homeowners Choose Republic Building Contractors
- ADU specialists
- Fully licensed and insured
- Local zoning and permitting expertise
- Transparent pricing and clear timelines
- One point of contact from design to completion
What Is an Accessory Dwelling Unit (ADU)?
An Accessory Dwelling Unit (ADU) is a fully independent living space built on your existing residential property. ADUs can be attached to your home, detached as a separate structure, or created through garage or basement conversions.
ADUs are commonly used for:
In-law suites or multi-generational living
Rental income or Airbnb opportunities
Guest houses or private home offices
Increasing property value without moving
We help you determine what is allowed, what makes financial sense, and how to build it correctly the first time.
How Our Process Works
Plan & Approve
We review your property, confirm zoning and feasibility, and create a clear ADU plan with realistic pricing and timelines.
Design & Permit
Our team handles architectural design, engineering, and all permitting so everything is approved before construction begins.
Build & Deliver
We construct your ADU from the ground up, manage inspections, and deliver a move-in-ready space with a final walkthrough.
Full-Service ADU Design & Construction
Most ADU projects fail because homeowners are forced to coordinate designers, engineers, and contractors themselves. We eliminate that risk.
Republic Building Contractors is a true design-build ADU contractor. That means we manage the entire process under one roof.
Our ADU Services Include:
Feasibility and zoning review
Architectural design and engineering
Permit management and approvals
Site preparation and utilities
Full construction and inspections
Final walkthrough and close-out
One team. One contract. One partner.
ADU Options We Build
Not sure what works for your property? We will walk you through your best options during your consultation.
Detached ADUs
Standalone units built on your property, ideal for rentals, privacy, or long-term income.
Attached ADUs
Connected additions that blend seamlessly with your existing home.
Garage or Basement Conversions
Transform underused space into a fully functional living unit.
Explore the Common Questions We're Asked About Accessory Dwelling Units
Can I legally build an ADU on my property?
Currently, accessory dwelling units are allowed ‘by right’ on single-family lots in Massachusetts & New Hampshire. Republic Building Contractors ensures your ADU fully meets all local building codes, so you don’t have to worry about compliance.
Can my ADU be used as a rental or Airbnb?
In many cases, your accessory dwelling unit can be used as a rental or Airbnb. We help you understand local rules and design your new ADU to align with your goals.
Do you handle the entire ADU process from design to completion?
Accessory dwelling units require expert oversight to ensure proper design, efficient permitting, and code-compliant construction. Republic Building Contractors manages the entire process from design and permitting/zoning to construction and final delivery, providing a streamlined, fully compliant, move-in ready ADU.
Should I build an attached or detached ADU?
Many homeowners build an attached accessory dwelling unit because it generally costs less. However, others build a detached one because it offers more privacy, higher rental income, and greater property value. We’ll help you determine which option is the best fit for your property, budget, and long-term goals.
How much does an ADU cost?
Most of our ADUs range from $290-390 per square foot, depending on size, layout, finishes, and site conditions. Our pricing includes design, permitting and construction.
Costs can vary or increase based on:
- Utility trenching distance
- Foundation type
- High-end finishes
- Sloped lots
- Separate utility meters
- Variances if required
- Storm Water Management (varies by town)
How long will my ADU project take?
A typical ADU project takes 6 - 9 months from start to finish, depending on permitting timelines and scope.
Here’s what that usually looks like:
- 2–4 weeks: Initial consultation & feasibility review
- 4–8 weeks: Design & architectural plans
- 4–6 weeks: Permitting (varies by municipality)
- 4–6 months: Construction
We provide a detailed project timeline before construction begins so you know exactly what to expect.
Ready to Build Your ADU?
If you are considering an ADU, the first step is understanding what is possible for your property. Schedule a free consultation with Republic Building Contractors and get clear answers, realistic timelines, and expert guidance.