Boston Landmarks Commission: Historic Preservation Authority

The Boston Landmarks Commission (BLC) is the city agency responsible for identifying, evaluating, and protecting Boston's historically and architecturally significant properties. Established under Massachusetts General Laws Chapter 772 of the Acts of 1975, the BLC operates as the principal regulatory body for historic preservation within Boston's city limits. Its decisions directly affect building permits, exterior alterations, demolitions, and long-term stewardship of properties ranging from individual landmark buildings to entire historic districts.

Definition and scope

The Boston Landmarks Commission holds authority under Boston's municipal preservation ordinance and the enabling state legislation that created it. The agency's primary function is to designate landmarks and local historic districts, then enforce design review standards for any proposed changes to designated properties.

Two distinct designation categories define the BLC's scope:

1. Individual Landmark Designation — Applied to a single structure, object, or site of historical, architectural, or cultural significance. Designated landmarks receive the full protection of the city's preservation review process.
2. Local Historic District (LHD) Designation — Applied to a defined geographic area containing multiple contributing properties. Boston maintains 9 local historic districts, including the Beacon Hill Local Historic District — one of the oldest in the United States, established in 1955 — and the Bay Village, Fort Point Channel, and Back Bay Architectural Districts.

The BLC also maintains a Preliminary Landmark Designation status, which provides interim protection for properties under active study before a final vote. This status prevents demolition or incompatible alterations from proceeding while the commission completes its evaluation.

Scope, coverage, and limitations: The BLC's jurisdiction applies exclusively to properties within the City of Boston's municipal boundaries. It does not cover Cambridge, Somerville, Quincy, or any other municipality in the broader metropolitan area — those cities maintain their own local historic preservation bodies. Properties listed only on the National Register of Historic Places are not automatically subject to BLC review; National Register listing is an honorary federal designation that does not carry local regulatory authority unless the property is also locally designated. State-owned properties within Boston may fall under the Massachusetts Historical Commission's jurisdiction rather than the BLC's, depending on the nature of the project and funding sources. The Boston Planning & Development Agency handles zoning and large-scale development review separately from the BLC's historic preservation mandate.

How it works

The BLC process follows a structured sequence from initial study to regulatory enforcement:

1. Petition or Staff Initiation — A landmark study may be initiated by petition from a property owner, a civic organization, or directly by BLC staff. The commission votes whether to accept the study.
2. Research and Evaluation — Staff prepare a written report documenting the property's historical associations, architectural significance, and physical integrity against established criteria derived from the Secretary of the Interior's Standards for Evaluation (National Park Service, 36 CFR Part 60).
3. Public Hearing — The commission holds a noticed public hearing at which owners, abutters, and interested parties may testify. Hearings are governed by Boston's Open Meeting Law requirements.
4. Designation Vote — A majority vote of the nine-member commission is required for designation. Commissioners are appointed by the Mayor of Boston (Boston Mayor's Office) and serve staggered terms.
5. Design Review (post-designation) — Any proposed exterior alteration, addition, demolition, or new construction affecting a designated landmark or contributing structure within a local historic district requires a Certificate of Appropriateness (COA) from the BLC before a building permit may be issued by Boston Inspectional Services.

The Certificate of Appropriateness is the primary regulatory instrument. Without an approved COA, the Boston Building Permits office cannot legally issue a permit for covered work. This creates a hard sequencing requirement: BLC review precedes permit issuance, not the reverse.

Common scenarios

Property owners, developers, and contractors encounter BLC jurisdiction in predictable contexts:

• Window and door replacement on a designated landmark or within a local historic district requires COA review. Replacing original wood windows with vinyl units is typically found incompatible; in-kind wood replacements or aluminum-clad wood substitutes may be approved.
• Masonry repointing using Portland cement mortars harder than original lime-based mortars can cause long-term damage to historic masonry. The BLC frequently conditions approvals on use of softer, compatible mortar mixes consistent with NPS Preservation Brief 2.
• Additions and new construction adjacent to designated structures are reviewed for compatibility in scale, massing, materials, and setback. The BLC does not require new construction to mimic historic styles but does evaluate whether additions are distinguishable yet subordinate.
• Demolition review for any structure over 50 years old within Boston triggers a separate Demolition Delay Ordinance review by BLC staff, regardless of landmark designation status. The delay period can extend up to 18 months for properties found to be preferably preserved, providing time to explore alternatives.
• Signage and storefront alterations in commercial historic districts require review when changes affect primary facades.

The Back Bay neighborhood — which falls within the Back Bay government services area — sits within the Back Bay Architectural District, making storefront and facade alterations in that neighborhood among the most frequently reviewed project types in the BLC's annual caseload.

Decision boundaries

The BLC's authority has defined limits that distinguish it from adjacent regulatory bodies.

BLC authority applies to:
- Exterior alterations visible from a public way on designated individual landmarks
- All exterior changes to contributing and non-contributing structures within local historic districts (standards differ by contributing status)
- Demolition of structures subject to the Demolition Delay Ordinance
- Relocations of designated structures

BLC authority does not apply to:
- Interior alterations, which remain entirely outside BLC jurisdiction unless the interior space itself carries a separate interior landmark designation (rare)
- Routine maintenance that replicates existing materials exactly in kind
- Emergency stabilization work ordered by city inspectors for public safety
- Federal undertakings, which instead trigger Section 106 review under the National Historic Preservation Act of 1966 — a process coordinated through the Massachusetts Historical Commission

The distinction between the BLC and the Boston Zoning Board of Appeal is operationally significant. The ZBA reviews variances and special permits under the Boston Zoning Code; the BLC reviews design compatibility under preservation standards. A project may require approvals from both bodies independently, and approval by one does not substitute for the other.

The /index for this site provides an overview of Boston's full municipal governance structure, situating the BLC within the broader network of city agencies and commissions that shape land use, development, and neighborhood character across Boston's 23 recognized neighborhoods.

References

• Boston Landmarks Commission — City of Boston
• Massachusetts General Laws, Chapter 772 of the Acts of 1975
• National Park Service — National Register Criteria for Evaluation, 36 CFR Part 60
• National Historic Preservation Act of 1966 — National Park Service
• Secretary of the Interior's Standards for the Treatment of Historic Properties — NPS
• NPS Preservation Brief 2: Repointing Mortar Joints in Historic Masonry Buildings
• Massachusetts Historical Commission