Massachusetts 10th Edition Building Code: A Guide for Commercial and Multifamily Building Owners

Authored by: Rimkus Built Environment Solutions Marketing Team

Massachusetts’ 10th Edition building code does not require every existing building to be brought fully up to current code. A permit-triggering project, such as an alteration, addition, or change of occupancy, can require targeted upgrades beyond the immediate work area, depending on scope, compliance path, and use.

The 10th Edition of the Massachusetts State Building Code (780 CMR) took effect on October 11, 2024, and building permit applications filed on or after July 1, 2025, must comply with it..

This guide covers who governs what, how Chapter 34 classifies compliance paths, what actually changed in the 10th Edition, and which fire and accessibility obligations still apply regardless of edition.

Key takeaways: what changed under Massachusetts’ 10th Edition

Massachusetts’ 10th Edition applies to filings on or after July 1, 2025, but it does not require every existing building to meet current code. A permit-triggering project can still expand a building’s compliance obligations beyond the immediate work area.

What applies automatically

• Permit applications and related construction documents filed on or after July 1, 2025 must comply with the 10th Edition of 780 CMR
• Lawful existing occupancy may continue, though owners must maintain regulated systems and required life safety features

What depends on the project

• Chapter 34 no longer includes a Massachusetts performance compliance method; repair, work area, and prescriptive paths govern most alterations
• Fire safety, accessibility, energy, and flood requirements arise under separate statutes, not 780 CMR alone

For help evaluating a specific building against the 10th Edition, contact us.

Massachusetts Building Code: 9th Edition vs. 10th Edition

Side-by-side comparison of 780 CMR provisions between the 9th Edition (2015 model code family) and 10th Edition (2021 model code family), covering compliance methods, structural loads, energy, flood, and provisions that carried forward unchanged.

Sources: BBRS 10th Edition of 780 CMR; M.G.L. c. 148, § 26G; Mass.gov concurrency notice (July 1, 2025); 521 CMR 3.3.2. Reflects factual corrections confirmed September 2026.

Who governs what: Building, fire, accessibility, and energy authorities

The Board of Building Regulations and Standards (BBRS) adopts 780 CMR under Massachusetts General Laws (M.G.L.) chapter 143, sections 93 through 100, and local building officials enforce it in cities, towns, and on state-owned property. Separate authorities govern separate obligations: the fire official enforces the Massachusetts Comprehensive Fire Safety Code, 527 CMR 1.00, references to which appear throughout 780 CMR but carry their own enforcement and appeals process.

Accessibility requirements fall under 521 CMR, and energy requirements fall under 780 CMR chapter 13 alongside any municipality’s adopted Stretch or Specialized Energy Code. Plumbing, electrical, elevator, and mechanical work can involve additional state licensing boards and inspection requirements, so a project touching several of these areas often needs sign-off from more than one authority before work proceeds.

Compliance paths under Chapter 34

Chapter 34 governs work on existing buildings and is built on the 2021 International Existing Building Code framework, adapted for Massachusetts use. The applicable code edition follows the permit filing date, not the design date.

Massachusetts recognizes repair, work area, and prescriptive compliance paths under Chapter 34, along with separate provisions for additions, changes of occupancy, historic buildings, and relocated buildings. The model International Existing Building Code also includes a performance compliance method, but Massachusetts struck that chapter from the 10th Edition, so it is not an available path here. The applicable path depends on project scope, and a single project can involve more than one, for example a Level 2 alteration paired with an addition or a change of occupancy.

The work area method’s three levels

The work-area method is a Chapter 34 compliance path that organizes alteration requirements according to the scale of the proposed work. It classifies alterations into three levels:

• Level 1: removal and replacement, or covering, of existing materials, elements, equipment, or fixtures with new items serving the same purpose
• Level 2: reconfiguration of space, addition or elimination of doors or windows, reconfiguration or extension of systems, or installation of additional equipment, where the work area is 50% or less of the building area
• Level 3: alterations where the work area exceeds 50% of the building area; Level 3 work must also satisfy the applicable Level 1 and Level 2 provisions

Depending on occupancy, work area, and existing conditions, Level 2 and Level 3 work can trigger requirements for egress, fire protection, alarms, sprinklers, structural capacity, or accessibility.

For projects subject to the Chapter 34 investigation requirement, the permit submission must document the proposed work’s effect on structural systems, egress, fire protection, energy conservation, hazardous materials, and accessibility, among the categories listed in section 104.2.2.1.

A separate set of fire safety statutes, addressed below, can apply independently of Chapter 34 depending on a building’s height, age, and size.

What actually changed in the 10th Edition

Several notable 10th Edition changes affecting existing buildings are structural. Fire and accessibility rules remain largely as they were and are addressed separately below.

Structural loads: wind, snow, and seismic

Wind loads are generally 5% to 15% lower in most locations under the 10th Edition, alongside new guidance on wind uplift pressure for roof-mounted solar panels. Seismic design values increase across many parts of the Commonwealth under the updated hazard maps, which can affect structural detailing and non-structural bracing requirements for some buildings, and a structural engineering review can confirm which mapped values apply to a specific site.

Snow load provisions are more explicit than in the 9th Edition. Section 1604.11 codifies local increases in design snow load at higher elevations, and the referenced ASCE 7-16 standard addresses snow accumulation on open-framed structures and adds prescriptive clearances to limit snow drift against elevated rooftop equipment.

New requirements for existing conditions

Several 10th Edition provisions reach conditions the 9th Edition left to case-by-case judgment. A repair involving substantial structural damage to snow load carrying elements must now meet current snow load requirements as part of that repair. Adding insulation to an existing roof in a way that increases the American Society of Civil Engineers (ASCE) 7 standard’s thermal factor now requires checking the structure’s capacity for added snow accumulation, and new provisions help identify roof bays at risk of ponding instability.

Masonry evaluation also changed: the 10th Edition sets prescriptive strength values for masonry, and those values apply unless more precise values are obtained through testing, other Chapter 34 provisions, or justified historical information. For major renovations in which more than 50% of the building area is reconfigured, Chapter 34 requires evaluating the anchorage of interior unreinforced masonry partitions for out-of-plane seismic forces and strengthening those without sufficient capacity.

A new requirement for frost-protected egress landings rounds out the changes: outward-swinging egress doors now need an exterior landing protected against frost heave, using non-frost-susceptible soil or below-grade insulation.

Ground improvement techniques gain code recognition

The 10th Edition adds specific design, inspection, and construction provisions for ground improvement techniques, such as rigid inclusions used to strengthen soil beneath foundations, an area earlier Massachusetts code editions addressed far less explicitly.

Flood provisions

In mapped flood hazard areas, proposed reconstruction, rehabilitation, repair, alteration, addition, or improvement can require a substantial improvement, substantial damage, or substantial foundation repair determination. Where the applicable threshold is met, the building official may require compliance with the current flood resistance provisions in section 1612, which incorporate updated ASCE 24 tables under the 10th Edition. Owners should confirm the applicable flood zone, Flood Design Class, and elevation or freeboard requirement with the local building official before finalizing project scope.

Energy code and commissioning

The base code in 780 CMR chapter 13, 10th Edition, follows the 2021 International Energy Conservation Code, up from the 2015 edition referenced by the 9th Edition. Energy requirements for existing building work depend on the scope of alteration and the applicable base, Stretch, or Specialized Energy Code; the altered component or system is often the focal point, but project-specific requirements can extend beyond the immediate work area.

Section 111.1 applies building commissioning or acceptance-testing documentation showing performance as designed to new nonresidential buildings larger than 10,000 square feet and to major reconstruction, alteration, or repair of such buildings. Those records, which document testing of the new mechanical systems, must be completed before the building official issues a certificate of occupancy.

Fire safety and accessibility obligations that continue to apply

Fire safety and accessibility requirements are largely carried forward from prior editions rather than changed by the 10th Edition, though they remain some of the most consequential triggers owners encounter. Sprinklered buildings still need the alarm and signal transmission features required by 780 CMR sections 903.4.2 and 903.4.4, and exterior stairs and fire escapes still need certification every five years under section 1001.2.2.

M.G.L. chapter 148, section 26G generally requires adequate automatic sprinkler protection throughout certain nonresidential buildings, structures, additions, or major alterations that exceed 7,500 gross square feet, subject to the statute’s water supply and pressure condition and its stated exceptions, which exclude agricultural buildings and buildings or additions used for residential purposes. Separate statutes address certain high-rise buildings and certain pre-1975 high-rise buildings, and applicability depends on the building’s height, age, use, and work scope rather than a single trigger.

Under 521 CMR 3.3.2, work, including exempt work, totaling 30% or more of a building’s full and fair cash value can require the entire building to comply with 521 CMR, subject to the regulation’s sub-30% and dollar-threshold provisions and its other terms and exceptions. A fire code review can help evaluate existing sprinkler coverage and accessibility exposure against these requirements.

Evaluating compliance for a proposed project

A targeted code review can help identify documented compliance gaps or capacity gaps in older systems once a permit trigger arises. For a filed application, 780 CMR states that the building official shall issue or deny the permit in writing within 30 days, and the code separately provides a 30-day response period for the acceptability of any proposed compliance alternative, a substitute safety measure offered in place of a strict code requirement. Neither timeline guarantees approval of an incomplete submission.

A property condition assessment serves a different purpose and should not be treated as a code compliance certification: American Society for Testing and Materials (ASTM) standard E2018-24 identifies its section 12.2 as addressing warranty, guarantee, and code compliance exclusions. Rimkus offers a property condition assessment service for owners who need that separate review.

For condominium boards

Condominium boards allocating code upgrade costs should review the association’s master deed, bylaws, budget, reserve policies, and applicable provisions of M.G.L. chapter 183A before setting a scope, since required approvals and assessment authority can vary with the work and the governing documents. A condominium consulting review addresses code triggers, a separate exercise from a reserve study, which addresses funding.

Owner checklist before starting a permit application

Before scoping a project under the 10th Edition, an owner or design team typically works through a short sequence of confirmations.

• Confirm which code edition applies to the filing date
• Confirm the building’s occupancy, use, and proposed work scope
• Identify every authority having jurisdiction over the project
• Determine the applicable Chapter 34 compliance path and work area
• Obtain the required investigation and evaluation report where Chapter 34 applies
• Check fire safety, accessibility, energy, and flood triggers separately
• Preserve permits, plans, inspection reports, and certificates of occupancy

For help evaluating an existing building against the 10th Edition, contact Rimkus to discuss specific requirements.

Frequently asked questions about Massachusetts building code compliance

When did the Massachusetts 10th Edition building code take effect?

The 10th Edition of the Massachusetts State Building Code (780 CMR) took effect on October 11, 2024. During a concurrency period that ended June 30, 2025, applicants could file under either the 9th or the 10th Edition, but not a combination of both. Building permit applications filed on or after July 1, 2025, must comply with the 10th Edition.

What records should property owners keep to support code compliance?

Property owners generally maintain permit files, approved stamped plans, final inspection certificates, contractor licenses, dated construction photographs, and correspondence with code officials. These records can help owners document that authorized work underwent required inspections and can support compliance reviews during sales, claims, or enforcement matters.

How does a condominium board determine a project’s work level before filing?

The board typically starts by measuring the proposed work area against the total building area, since a work area exceeding 50% of the building area places the project in Level 3 rather than Level 2. It then arranges the Chapter 34 investigation and evaluation report required by section 104.2.2.1 for submission to the building official as a condition of permit issuance.

This article is intended to provide general information and insights into prevailing industry practices. It is not intended to constitute, and should not be relied upon as, legal, technical, or professional advice. The content does not replace consultation with a qualified expert or professional regarding the specific facts and circumstances of any particular matter.