Merrimack County

Need a permit for a carport in Merrimack County? Usually yes, and it comes from the city or town where your land is, not from Merrimack County itself. In Concord, the city's residential building permit guide lists sheds and garages as work that needs a building permit, and it only exempts accessory structures and sheds of 60 square feet or less. Hooksett's zoning ordinance adds its own setback rules for accessory buildings, with stricter placement once a building goes over 200 square feet. Call or visit your local building office with the size and location of the building before you order it.

Permit office: Merrimack County does not issue building permits, so start with the building or code office in your own city or town. Here is one we were able to confirm:

• City of Concord Code Administration, Building Safety
  Concord Building Construction Requirements & Resources page

When a permit is required

• Concord: the Residential Building Permit Application Guide names sheds and garages among the projects that need a building permit.
• Concord's small building exemption is only 60 square feet. Accessory structures and sheds no larger than that skip the permit. A typical carport or metal garage is well past that size.
• Concord: every application goes through zoning and site review before the permit is issued. If a project needs relief from the zoning rules, it can go to the Zoning Board of Adjustment.
• Hooksett: under the town's zoning ordinance, an accessory building over 200 square feet has to meet the same setbacks as the house.
• New Hampshire rule: the state building code amendments let a one-story detached accessory building of 200 square feet or less go without a building permit. Towns are allowed to be stricter, and Concord is. Zoning setbacks still apply at any size.

Zoning and setbacks

Setbacks are set by each town's zoning ordinance, so the same carport can fit on one lot and not on another. Hooksett's ordinance lets an accessory structure of 200 square feet or less and no taller than 17 feet sit as close as 10 feet to the property line, but not in front of the line of the house facing the street. Anything bigger follows the main building setbacks for its district. In Hooksett's Low Density Residential district that means 35 feet from the front, side yards that add up to 50 feet with at least 20 feet on each side, and 25 feet from the rear. In Concord, the plot plan you submit is how the city checks setbacks, so it has to show the distance from the building to the front, side and rear lines.

What to bring

• A plot plan showing where the new building goes, its distance to the front, side and rear property lines, and the driveway location (Concord requires this for new accessory buildings).
• Scaled drawings at 1/4 inch to 1 foot, including floor plan, foundation plan, elevations and framing or structural details (Concord's residential guide).
• For small outbuildings in Concord, the city's Shed Design Worksheet and sample plot plans show what the office expects.

Farm buildings

Farm buildings in Merrimack County still go through the normal building permit process. New Hampshire has no blanket exemption, though the state adopted IBC Appendix C for Group U agricultural buildings. On zoning, RSA 674:32-a treats agriculture as allowed where a town's zoning says nothing about it, and RSA 674:32-c lets the local board waive setbacks or other dimensional rules that are unreasonable for a farm use. Ask about both when you apply.

Good to know

Concord takes permit applications through its Citizen Self Service (CSS) Permit Portal. Once the application is approved, the city emails you to pay the fees and then emails the permit after payment. Snow load matters here: Concord's structural loads sheet sets a ground snow load of 70 pounds per square foot at 600 feet of elevation, changing about 2.1 psf per 100 feet, so roughly 61.6 to 75.8 psf across the city. It also lists a 90 mph design wind speed and frost depth of at least 48 inches below grade. Ask for a building rated for those numbers.

Common questions

Do I need a permit for a carport in Merrimack County?
Most likely, yes, but the county does not issue it. Your city or town building office does. Concord exempts only sheds and accessory structures of 60 square feet or less, and Hooksett's zoning ordinance sets setbacks for accessory buildings of every size.

Does a metal garage or shed need a building permit in Concord?
Yes, unless it is 60 square feet or smaller. Concord's residential guide lists sheds and garages as permit work, and the application needs a plot plan and scaled drawings. You apply through the city's Citizen Self Service Permit Portal.

What snow load does a carport need to handle in Concord?
Concord's structural loads sheet uses a ground snow load of 70 psf at 600 feet of elevation, ranging about 61.6 to 75.8 psf across the city. Roof snow load is then worked out from that number under ASCE 7. The same sheet sets a 90 mph wind speed and 48 inch frost depth.

Sources

• City of Concord: Building Construction Requirements & Resources
• City of Concord: Residential Building Permit Application Guide
• City of Concord: Structural Loads for Concord, NH
• Town of Hooksett Zoning Ordinance (2021 revised)
• NH RSA 155-A, State Building Code
• NH RSA 674:32-c, Agricultural Uses of Land

Rules and fees change. Call the office to confirm before you order.

See the full New Hampshire permit guide for statewide rules, farm exemptions and wind and snow ratings.

Looking at buildings? See our metal carports, metal garages and metal buildings.

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Design it yourself in 3D with the button below, or call 919-725-8176 and we'll help you figure out what your county needs.