ConCORD ADU RESOURCES

Considering an Accessory Dwelling Unit (ADU) in Concord?

Your Concord ADU Experts: Design, Navigate, Build.

With Chris Bailow's 25 years of architectural leadership, Bailow Architects is your trusted partner for Accessory Dwelling Units in Concord. We specialize in crafting innovative, beautifully designed ADUs that honor New England's timeless aesthetic while expertly navigating Concord's specific zoning (allowing up to 1,200 sq ft by-right). Whether it's for family, rental, or a dedicated workspace, our lean model ensures exceptional quality and value, from concept to completion. Ready to explore the possibilities? We're here to help.

Infographic: Building an ADU in Concord, MA

A New Era for ADUs in Concord

The Massachusetts Affordable Homes Act has streamlined the rules for Accessory Dwelling Units (ADUs). Here's what homeowners in Concord need to know.

A Statewide Push for Housing

The new state law is designed to significantly boost housing supply. The change is expected to be impactful across the Commonwealth.

8,000-10,000
Projected New ADUs in MA in the Next 5 Years

The Core Conflict: State Law vs. Concord's Bylaw

The state sets a baseline for "by-right" development, but Concord's proposed rules create a key point of difference. State law likely preempts local rules where they conflict.

Maximum "By-Right" Size Comparison

The state mandates by-right approval for ADUs up to 900 sq ft. Concord's proposed 1,000 sq ft bylaw might still require a special permit for units between 901-1,000 sq ft due to state preemption.

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Owner Occupancy

Both state law and Concord's proposal eliminate the requirement for the owner to live on the property, increasing rental flexibility.

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Parking Requirements

Both align: 0 spaces required if within 0.5 miles of transit, and a max of 1 space otherwise.

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Short-Term Rentals

The state allows local control. Concord's bylaw prohibits using ADUs for tourist/B&B purposes.

Concord's ADU Journey: A Timeline of Change

1974

Special Permits Begin

Concord first allows ADUs, but the process is discretionary and requires a special permit.

2020

Bylaw Modernized

Rules are updated, allowing 750 sq ft by-right and removing the clause that expired permits on property sale.

2024

State Law Passes

The MA Affordable Homes Act is signed, mandating by-right ADUs up to 900 sq ft statewide.

2025

Regulations Align

The state law becomes effective, and Concord discusses Article 39 to align local bylaws.

The Reality Check: Navigating Practical Hurdles

Streamlined zoning is a huge step, but building an ADU is still a major project with real-world financial, environmental, and community challenges.

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Financial Investment

Be prepared for significant costs. New construction can range from $300k to $500k, and your annual property taxes will increase.

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Environmental & Site

All projects must comply with Title 5 (septic) and Wetlands Protection laws. Site constraints can limit or complicate development.

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Community & Abutters

Neighbors may have valid concerns about privacy, density, and character. Proactive communication and thoughtful design are key.

Your Path Forward: A Simplified Checklist

1. Verify Final Bylaw

Contact the Concord Planning Dept. to confirm the official outcome of the Article 39 vote. This is your most critical first step.

2. Conduct Site Analysis

Assess your property for setbacks, environmental constraints (wetlands, septic), and potential impacts on neighbors.

3. Engage Town Departments

Talk to Planning, Building, Health, and Conservation officials early to understand all requirements for your specific lot.

4. Assemble Your Team

Engage an architect, engineer, and contractor. Their expertise is crucial for navigating design, compliance, and construction.