Town of Mamaroneck, New York Building Permit Guide

In the Town of Mamaroneck, building permits for the unincorporated area come from the Building & Code Enforcement office at Town Center, 740 West Boston Post Road (914-381-7830). Every application is filed on the town’s Viewpoint Cloud (OpenGov) portal with sealed plans and the contractor’s Westchester County license. Under the fee schedule the Town Board updated on May 4, 2026, a residential permit is $150 for the first $1,000 plus $17 per $1,000 of construction cost. Larchmont and the Village of Mamaroneck issue their own permits.

What requires a building permit in the Town of Mamaroneck?

Chapter 106 of the Town Code requires a separate permit for each building or structure that is erected, enlarged, altered, converted or changed in use; only ordinary repairs that are not structural are excluded, and cutting walls, removing beams or changing exits never counts as an ordinary repair. The department’s own list shows how far that reaches:

Separate town permits often ride alongside: erosion and sediment control from the Engineering Department, highway work permits from the Highway Department and tree removal permits from the Environmental Planner.

What the town decides and what the state sets

The Uniform Code governs construction, but the town has used its option to go further on energy: under Local Law 10 of 2021 the NYStretch Energy Code 2020 (except section R403.6.2) is enforced in full in the unincorporated area, and the department’s page, updated for the 2025 codes that took effect on December 31, 2025, tells applicants to apply whichever of NYStretch or the 2025 Energy Code is more restrictive for each component. Zoning (Chapter 240), wetlands and watercourses (Chapter 114), flood damage prevention (Chapter 110), trees (Chapter 207) and coastal zone management (Chapter 8) are town law.

Town of Mamaroneck building department: who handles permitting

The Town Board governs the unincorporated area, and its Building & Code Enforcement office, led by Building Inspector Richard Polcari, permits only that area. Of the town’s 31,479 residents (Census 2025 estimate), 12,586 live there; everyone else is in one of two villages with their own building departments. The Village of Mamaroneck straddles the town line, with 12,143 residents in the Town of Mamaroneck and 7,753 in the Town of Rye, and one village office covers both parts.

Larchmont’s staff first decide whether a project needs its Planning, Zoning or Architectural Review board and otherwise issue permits administratively. The Village of Mamaroneck handles building, plumbing, electrical, demolition, sign, tree and dumpster permits and writes the certificate letters buyers and lenders ask for.

Town of Mamaroneck permit types and filing rules

Residential permits

All applications go through the Viewpoint Cloud (OpenGov) portal; you create an account the first time you log in. The February 25, 2026 filing instructions list what to upload: plans signed and sealed by a New York design professional (manufacturer’s specifications may replace plans for air conditioners, generators, fences and similar work), a survey of existing conditions and a plot plan of the proposed work (neither needed for interior jobs), the contractor’s Westchester County home improvement license and insurance certificates naming the Town of Mamaroneck as certificate holder and additional insured, with disability on form DB-120 and workers’ compensation on C-105.2 or a CE-200 exemption.

The town also posts a zoning data form, residential bulk and dimensional tables, minimum drawing requirements, an owner authorization form, a cost affidavit used when requesting a certificate, and requirement sheets for pools, HVAC, demolition, blasting and rock removal. Revised plans must have every change clouded, numbered and dated, with a narrative if the scope changes; after a permit issues a revision costs $125.

Building or remodeling a home here? Alliance handles residential permit applications, so the crew isn't waiting on the counter.

Commercial permits

Commercial work follows the same portal route at the commercial rate ($200 for the first $1,000 plus $25 per $1,000). Site plan approval costs $350 plus $25 for each required parking space, and a new business uses the town’s New Business Review Form. Commercial demolition is $250 for the first $1,000 plus $25 per $1,000.

For tenant improvements and new commercial builds, Alliance handles commercial building permits through issuance. More on this: commercial building permits explained.

What comes before the building permit

• Zoning Board of Appeals: $300 for the first area variance and $125 for each extra variance; a use variance is $300.
• Board of Architectural Review: $125 per application.
• Residential site plan under Chapter 178: $400, plus $25 per parking space beyond two where zoning requires them.
• Wetlands and watercourses: $200 permit application under Chapter 114.
• Flood zones: a floodplain development permit costs a $100 filing fee plus up to $1,500 to cover review costs.
• Erosion control: for an existing one- or two-family home, a $250 filing fee and $200 permit, plus $100 per inspection; fees double if work starts first.
• Septic: any new septic system needs a Westchester County Department of Health permit.

Town of Mamaroneck building permit fees

Fees sit in Chapter A250 of the Town Code. On May 4, 2026 the Town Board approved the 2026 update to the A250 fee schedule, adding the revised-plan and failed-inspection fees; the codified chapter online still shows the older 2022 figures, so budget from the 2026 sheet.

The schedule does not say whether the $17 rate applies to the first $1,000 as well, so ask the department to price a large project before you budget.

Trade permits and who may pull them

Electrical. The A250 schedule charges $150 for an electrical permit, letter of completion included, and the town says most work on fixed wiring needs a compliance certificate from a private electrical inspection service. Chapter 90 deputizes New York Board of Fire Underwriters inspectors at no cost to the town, and Westchester County requires every non-government electrical inspector to hold a county license (county list of approved agencies). The code lets only a licensed electrician do the work, or the owner-occupant of a one-family house working on that house.

Plumbing and gas. Chapter 158 limits plumbing in the town to plumbers licensed by Westchester County; the permit application is signed by a licensed master plumber, and house sewers to the street line are laid by a licensed plumber. Fixtures, water lines, drain and vent lines, furnaces and water heaters need a plumbing permit.

Home improvement contractors. The county’s Department of Consumer Protection, 148 Martine Avenue, Room 407, White Plains (914-995-2155), licenses home improvement contractors, master plumbers and master electricians; the home improvement application fee has been $750 since January 1, 2026. The town’s filing instructions require a copy of that license.

Sewer discharge certificate. After a sale closes, a house in the unincorporated town cannot be occupied until the town issues a discharge compliance certificate ($150) confirming that sewer and storm connections meet code and that no pumps, hoses or leaders discharge toward the street.

How to apply in the Town of Mamaroneck

Review, corrections and what causes delay

The town publishes no review time; Chapter 106 says applications are approved or disapproved within a reasonable time, and a denial on zoning grounds goes to the Zoning Board of Appeals. Missing licenses or insurance certificates, plans without a New York seal and unclouded revisions are the common holdups. A permit lasts one year; the Building Inspector may grant up to two six-month extensions, but each must be requested before the permit or the previous extension runs out.

Inspections and certificates of occupancy

Request inspections from the Building Department at 914-381-7830 as each stage is ready; a failed or missed inspection costs $100 under the 2026 schedule. Electrical work is inspected by the private agency, and its compliance certificate is needed before the job can close.

A new building cannot be used until the town issues a certificate of occupancy, and an altered building that stayed occupied during work may be used for no more than 30 days after completion without one. Before the certificate, the architect or engineer who filed or supervised the work (or the superintendent of construction) files an affidavit that the work matches the approved plans. New construction placed to meet setbacks also needs an as-built survey signed and sealed by a New York land surveyor. The certificate is issued within 30 days of a complete written application; small jobs close with a letter of completion instead.

New York building code

New York builds on one statewide code, the Uniform Code, outside New York City; the 2025 edition and 2025 Energy Code took effect on 31 December 2025 (the all-electric provisions remain suspended by court order). Cities, towns and villages administer it, and local standards stricter than the code need Code Council approval. The Uniform Code in New York

Town of Mamaroneck permit FAQ

Does the town Building Department cover Larchmont?

No. The Village of Larchmont has its own Building/Engineering Department at 120 Larchmont Avenue, and the Village of Mamaroneck has its own at 169 Mount Pleasant Avenue. The town office covers only the unincorporated area.

Can I file on paper?

The town has switched to online permitting: applications and documents are uploaded to its Viewpoint Cloud (OpenGov) portal.

Do I need a permit for a fence, patio or generator?

Yes. The town lists fences, generators and exterior impervious surfaces such as driveways, patios, sidewalks and retaining walls among the work that needs a building permit; manufacturer’s specifications can replace plans for fences and generators.

Which energy code applies to my addition?

Both the 2025 Energy Code and the 2020 NYStretch Energy Code, which the town adopted in 2021; the department asks you to meet whichever is stricter for each building component.

Can a homeowner do their own electrical work?

Chapter 90 allows the owner-occupant of a one-family house to do electrical work in that house; otherwise the electrician must be licensed. The work still needs a private inspection agency’s compliance certificate.

What happens if I start before the permit issues?

A legalization permit costs three times the normal permit fee, and erosion control fees double when work begins early.

I just bought a house. Do I need anything from the town?

Yes, in the unincorporated town: a discharge compliance certificate ($150) after the title transfer, issued after an inspection of the sewer and stormwater connections.

Is the town in the federal flood insurance program?

Yes. FEMA lists the Town of Mamaroneck, the Village of Larchmont and the Village of Mamaroneck as participating communities, all on the Westchester County flood map effective September 28, 2007. In the unincorporated town, building in a mapped flood zone needs a floodplain development permit under Chapter 110 ($100 filing fee plus up to $1,500 toward review costs).

Permit search and official resources

Open permits can be followed on the OpenGov portal. Building property files are available in electronic format for $30, and a copy of a certificate of occupancy or letter of completion costs 25 cents; ask the Building Department at 914-381-7830 how to request them.

• Town of Mamaroneck Building & Code Enforcement
• Viewpoint Cloud (OpenGov) permit portal
• Application requirements, forms and instructions
• Instructions for filing a building permit (Feb. 25, 2026)
• A250 fee schedule, 2026 update
• Town Board minutes, May 4, 2026 (fee schedule approval)
• Town FAQs on building, electrical and plumbing permits
• Town of Mamaroneck Code
• Village of Larchmont Building/Engineering Department
• Village of Mamaroneck Building Department
• Westchester County plumber and electrician licenses
• Westchester County home improvement license fees
• Westchester County Health septic and well permits
• FEMA Community Status Book, New York
• NYS code adoption notice

Simplify Town of Mamaroneck permitting with Alliance Permitting

Alliance Permitting is a permit documentation and submission company in New York. We prepare your paperwork, file it correctly and coordinate with the permitting authority through issuance. We are not a contractor and we do not perform licensed plan review or inspections; that work stays with your licensed team and the jurisdiction.

This guide is provided by Alliance Permitting for general information about Town of Mamaroneck permitting. Requirements, fees, and procedures change; confirm details with the permitting authority before relying on them.