Apartment Building Insurance in Portsmouth, NH: What Owners of 5+ Unit Buildings Should Carry

Category: Commercial: Habitational · Apartment · NH
Reviewed by Jon Merwin, Founder and CEO
Published: October 22, 2026 · Updated: October 23, 2026

Apartment building insurance in Portsmouth, NH is a commercial policy that protects the owner of a 5+ unit building against damage to the building, lawsuits from tenants and visitors, and lost rent while the building is repaired. Most Seacoast owners also need equipment breakdown, ordinance or law coverage for code upgrades after a loss, and a separate flood policy near the Piscataqua or the coast. Below: what to carry, the Portsmouth and New Hampshire rules that shape it, and what to have ready for a quote.

What does apartment building insurance cover for a 5+ unit building?

At five or more units, most carriers write the building on commercial property and liability forms, often a businessowners policy (BOP) or commercial package. (For a duplex or triplex, start with dwelling fire vs. homeowners insurance.) The core pieces:

Building property

This pays to repair or rebuild the structure after a covered loss such as fire, wind, a burst pipe or snow load. The limit should reflect what it would cost to rebuild today, not the purchase price or assessed value. Ask about coinsurance, agreed value and when the valuation was last updated.

General liability

Liability covers the owner, including legal defense, when a tenant, guest or contractor is hurt on the property: an icy stairway, a loose railing, a dark parking lot. Owners of larger or multiple buildings usually add an umbrella or commercial excess liability policy on top.

Loss of rents (business income)

If a fire makes units uninhabitable, rent stops but the mortgage and taxes do not. Loss of rents replaces the income lost during repairs. Ask whether it is “actual loss sustained” or a fixed number of months, and whether that fits a rebuild that may need permits and historic review.

Equipment breakdown

Property forms generally exclude mechanical and electrical breakdown. Equipment breakdown responds when a boiler, panel, elevator or heating system fails from a power surge, short circuit or mechanical breakdown. Andover’s equipment breakdown materials, for example, say its coverage includes the periodic jurisdictional inspections of boilers and pressure vessels that most states require.

Ordinance or law

After a loss, the building official can require repairs to meet current code. A standard policy may not pay for tearing down the undamaged part, the demolition, or code upgrades such as egress or electrical work. Ordinance or law coverage fills that gap, which matters for downtown Portsmouth’s older brick and wood-frame buildings.

Core coverages for a 5+ unit apartment building: what each does and what to ask

Coverage	What it is for	Ask your agent
Building property	Repairing or rebuilding the structure after a covered loss	Is the limit based on a current replacement cost estimate? Coinsurance or agreed value?
General liability	Injury and property damage claims against the owner, plus defense costs	Are the LLC, the owners and the property manager all insured correctly?
Loss of rents	Rent lost while units are uninhabitable after a covered loss	Actual loss sustained or a fixed period? Does it fit a realistic rebuild time?
Equipment breakdown	Boilers, panels, elevators and HVAC that fail mechanically or electrically	Are boiler inspections included? Is resulting loss of rents covered?
Ordinance or law	Code-upgrade, demolition and undamaged-portion costs after a loss	Are all three parts (undamaged portion, demolition, increased cost) included, and at what limits?
Water backup	Water that backs up through drains or sewers or overflows a sump	Is it included or an endorsement? What is the sub-limit?
Flood (separate policy)	Surface water and storm surge, which property policies generally exclude	What flood zone is the building in? NFIP or private flood?
Umbrella or excess	Liability limits above the primary policy	Do the named insureds and underlying limits line up?

Where are the Seacoast’s 5+ unit apartment buildings?

Census estimates show Dover and Portsmouth with the most renter-occupied units in 5+ unit buildings in Rockingham and Strafford counties; in both, a majority of renter households live in buildings that size.

Rockingham and Strafford County towns ranked by renter-occupied units in buildings with 5+ units (estimates)

Rank	Town / city	County	Renter units in 5+ unit buildings	Margin of error (approx.)	All renter-occupied units	Share in 5+ unit buildings
1	Dover	Strafford	4,386	±597	7,121	62%
2	Portsmouth	Rockingham	3,061	±419	5,241	58%
3	Derry	Rockingham	2,452	±473	3,871	63%
4	Salem	Rockingham	2,300	±390	3,077	75%
5	Rochester	Strafford	1,924	±392	4,740	41%
6	Newmarket	Rockingham	1,476	±216	2,048	72%
7	Hampton	Rockingham	1,368	±279	2,069	66%
8	Somersworth	Strafford	1,088	±334	2,193	50%
9	Exeter	Rockingham	1,039	±233	2,132	49%
10	Londonderry	Rockingham	811	±186	1,426	57%

Source: U.S. Census Bureau, American Community Survey 2024 5-year estimates, Table B25032 (Tenure by Units in Structure), county subdivisions in Rockingham and Strafford counties, NH. “5+ unit buildings” sums the 5-9, 10-19, 20-49 and 50+ unit categories for renter-occupied units. Margins of error are approximate, combined from the Census Bureau’s published margins. Pulled October 3, 2026 from data.census.gov. Rankings between towns with overlapping margins of error, such as Derry and Salem, are not statistically distinct.

The Seacoast’s larger rental stock is concentrated in a few cities. If you own in Dover, our Dover, NH office page covers the local team.

What do Portsmouth and New Hampshire rules mean for your coverage?

None of these is an insurance rule, but each shows up in underwriting or claims. As of October 3, 2026:

Portsmouth’s rental Certificate of Occupancy

Portsmouth’s Housing Code, Chapter 14 of the city ordinances, requires anyone renting out a residential unit to first obtain a Certificate of Occupancy from the Housing Code Inspector and post it in the unit (Section 14.102A). The inspector must find the unit meets the code’s plumbing, heating, ventilation and safety sections first. A certificate is valid for 3 years but expires if the unit becomes vacant in that period. Keep copies: they document each unit’s condition for underwriters and adjusters. The city’s Inspection Department handles the process.

Smoke and carbon monoxide alarms

RSA 153:10-a requires every multi-unit dwelling and rental unit in New Hampshire to have fire warning devices installed under NFPA 101 and NFPA 72, plus carbon monoxide detection under NFPA 720 where there is fuel-burning equipment or an attached garage. The owner of a rental unit is responsible for maintaining them. The State Fire Code rules (Saf-C 6000) bar tenants from removing batteries or disconnecting alarms, and Portsmouth’s Housing Code requires smoke detection in every dwelling unit and common hallway outside single-family homes. The Portsmouth Fire Department’s alarm requirements page explains placement. Underwriters ask about alarms early.

Boilers in apartment houses

New Hampshire’s boiler and pressure vessel law, RSA 157-A, exempts only private residences and apartment houses of fewer than 3 units from its inspection requirements (RSA 157-A:6). So a 5+ unit building’s boiler is generally subject to state inspection, one more reason to carry equipment breakdown.

Older buildings and code upgrades

Under RSA 155-A, the repair and rehabilitation of existing buildings in New Hampshire is governed by the state building code, and Portsmouth has a Historic District Commission that reviews projects in the city’s historic district. Both can add time and cost to a rebuild, which is what ordinance or law coverage and an adequate loss of rents period absorb. (The city’s housing code rests on the authority in RSA 48-A.)

This is general information, not legal advice. Ask your attorney or the city about how these rules apply to your building.

What else should Seacoast apartment owners plan for?

Flood and storm surge

Commercial property policies generally exclude flood. If your building is near the harbor, the back channel or a tidal creek, check its zone on the FEMA Flood Map Service Center and read our guide to flood insurance on the Seacoast. Lenders on 5+ unit buildings in a mapped high-risk zone will usually require it.

Winter water losses

Nor’easters, ice dams and frozen pipes in vacant units are classic New Hampshire apartment claims. Ask how the policy treats water backup and vacancy, and keep heat on between tenants. Our posts on vacant property coverage and the landlord property inspection checklist have more detail.

Tenants and named insureds

Your policy does not cover tenants’ belongings, so many owners require renters insurance in the lease. If an LLC owns the building, make sure the LLC, its members and any property manager are named correctly on every policy.

Which carriers write apartment buildings through Portsmouth Atlantic Insurance?

As an independent agency working with 40+ carriers, we compare more than one market for each building. For Seacoast apartment buildings, that often includes:

• Vermont Mutual. We represent Vermont Mutual and do a lot of business with them across personal and commercial lines, including apartment buildings and master condo buildings.
• Concord Group and Safety Insurance. Both write apartment buildings of 5 or more units in New Hampshire through our agency, so we can compare their options side by side with our other markets.
• The Andover Companies. Andover’s materials describe a businessowners program for investment properties, with options such as loss of business income, equipment breakdown, ordinance or law, water backup and excess liability.

Availability varies by carrier, state and property, and every policy is subject to underwriting. Size, construction, age, updates, alarms and loss history all affect which carrier fits.

What should you have ready for an apartment building quote?

Frequently asked questions

What does apartment building insurance cover in Portsmouth, NH?

A commercial apartment policy for a 5+ unit building usually combines building property coverage, general liability for the owner, and loss of rents if a covered loss forces tenants out. Older buildings often add equipment breakdown and ordinance or law. Flood is a separate policy.

Do I need a Certificate of Occupancy to rent apartments in Portsmouth?

Yes. Portsmouth Ordinances Chapter 14, Section 14.102A, says no one may let a residential unit for occupancy without a Certificate of Occupancy from the Housing Code Inspector. A certificate is valid for 3 years unless the unit becomes vacant during that period.

Who is responsible for smoke and CO alarms in a New Hampshire apartment building?

The owner. RSA 153:10-a requires fire warning devices in multi-unit dwellings and rental units, plus carbon monoxide detection where there is fuel-burning equipment or an attached garage, and makes the owner of a rental unit responsible for maintaining them.

Is a 2-4 unit rental insured the same way as a 5+ unit apartment building?

Not usually. Many 1-4 family rentals can be written on a dwelling fire or landlord policy, while buildings with 5 or more units are generally written on commercial property and liability forms or a businessowners or package policy. The right fit depends on the carrier, the building and how it is owned.

Does apartment building insurance cover flood damage?

Generally no. Flood is bought separately through the National Flood Insurance Program or a private flood market. Check your building’s zone on the FEMA Flood Map Service Center first.

Sources

• U.S. Census Bureau, ACS 2024 5-Year Estimates, Table B25032: Tenure by Units in Structure (Rockingham and Strafford County subdivisions, NH)
• U.S. Census Bureau, ACS 5-Year 2024 variable list for group B25032
• City of Portsmouth, NH, Ordinances Chapter 14: Housing Code (Sec. 14.102A Certificate of Occupancy; Sec. 14.106 smoke detection)
• City of Portsmouth, NH, Inspection Department
• City of Portsmouth Fire Department, Smoke Alarm Device Requirements in Dwelling and Sleeping Units
• City of Portsmouth, Historic District Commission
• NH RSA 153:10-a, Automatic Fire Warning Devices and Carbon Monoxide Detection Devices in Dwellings
• NH Administrative Rules, Saf-C 6000, State Fire Code
• NH RSA Chapter 157-A, Boilers and Pressure Vessels
• NH RSA Chapter 155-A, New Hampshire Building Code
• NH RSA Chapter 48-A, Housing Standards
• FEMA Flood Map Service Center
• The Andover Companies, Businessowners Insurance
• The Andover Companies, Equipment Breakdown