Buying Land in Hillsborough County, New Hampshire

A dense urban corridor wrapped around a real rural fringe

Hillsborough County is where New Hampshire's population actually lives: roughly one resident in three in the entire state calls this county home, packed into 876.5 square miles anchored by Manchester (the state's largest city, 115,644 residents at the 2020 Census) and Nashua (its second-largest, with an estimated 2025 population near 92,000). Reported 2023 density figures put the county at around 491 people per square mile -- by a wide margin the highest of any county in northern New England. If your search is for a farm parcel, a wooded lot to build a first house on, or acreage to homestead, the Manchester-Nashua corridor itself is simply the wrong place to look; what you're shopping for there is a house, a commercial parcel, or an infill lot inside an already-dense zoning code, not raw land.

That said, don't write off the county entirely. Hillsborough's outer towns -- Mont Vernon, New Boston, Francestown, Greenfield, Hancock, Antrim, Bennington, Deering, Weare, Lyndeborough, Wilton, Temple, Mason, New Ipswich, Greenville, Hollis, and Brookline among them -- retain the low-density, agricultural, and rural-residential zoning typical of the rest of southern New Hampshire, and a genuine (if limited, and increasingly commuter-pressured) raw-land market exists there. The gradient from Manchester's dense urban core to these outer towns' working farms and woodlots happens over a surprisingly short distance, which is exactly why confirming a specific parcel's zoning district directly with its town -- rather than assuming anything from the county's overall urban reputation -- matters here more than almost anywhere else in the state.

Zoning is still a town matter, even in New Hampshire's biggest county

Nothing about Hillsborough's size or urban character changes the basic New Hampshire rule: zoning, subdivision regulations, and site plan review are set by each city or town under RSA Chapter 674, not by the county. Manchester and Nashua each run their own planning and zoning departments -- unsurprising for cities their size -- but so does every one of the county's smaller outer towns, each with its own zoning ordinance, planning board, and permitted-use table that can differ sharply from its neighbor. There is no Hillsborough County zoning office to call as a fallback or a shortcut; the specific municipality is always the first call, in Manchester exactly as much as in Mont Vernon.

For any rural parcel, the same state septic and subdivision rules apply

A raw parcel in one of Hillsborough's outer towns is subject to the same statewide layer that applies everywhere else in New Hampshire, covered in more depth on our state hub: any lot under 5 acres needs its own state Subdivision Approval from NHDES confirming the land can support a septic system or sewer connection (RSA 485-A:29-44, Env-Wq 1000), on top of and separate from the town's own subdivision approval. Septic design and permitting for any new system runs entirely through NHDES's Subsurface Systems Bureau, using a state-permitted septic designer -- not a Hillsborough County health department, which doesn't exist. Given the county's numerous small lakes and ponds (Franklin Pierce Lake, Powder Mill Pond, and others scattered through the hillier outer towns), also check a parcel's distance from any qualifying waterbody against the Shoreland Water Quality Protection Act's 250-foot protected zone before assuming a build or clearing plan is unrestricted.

Nashua's Inclusionary Zoning ordinance is a real cost factor for multi-unit land

Anyone evaluating multi-unit residential land in Nashua specifically should know the city runs an active Inclusionary Zoning ordinance under its Land Use Code (Section 190-48), requiring a share of units in qualifying new residential development to be affordable, in exchange for a density bonus that lets the project build more market-rate units than its base zoning would otherwise allow. The affordable units carry a 99-year deed restriction (for-sale) or a deed restriction and city lien (rental) -- a permanent feature of the project's economics, not a one-time approval cost. Manchester, the county's other large city, does not appear to run a comparable requirement under its own newly adopted Land Use Code (effective March 2026). See our dedicated housing-mitigation-requirements page for this county for the specific percentages, tiers, and bonus ratios involved.

Separately, Weare -- one of Hillsborough's outer, more rural towns -- hosts the Everett Dam half of the Hopkinton-Everett Lake flood-control system, a still-active U.S. Army Corps of Engineers project. The system's other dam and its larger flood-storage footprint sit in neighboring Merrimack County, where this project's dedicated flood-zones standalone for that system is developed in full; a Weare parcel near Everett Lake can still be affected by the same kind of federal flowage easement described there, so check that page if you're looking at land in Weare specifically.

What this means for a Hillsborough County land search

Start by being honest about which Hillsborough County you're shopping in. Near Manchester or Nashua, expect dense municipal zoning, sewer and water utility connections rather than septic and well, and land-buying that looks like ordinary urban or suburban real estate rather than raw-acreage purchase. Farther out -- Mont Vernon, New Boston, Francestown, Greenfield, Hancock, and the rest of the outer towns -- expect the state's standard rural due-diligence sequence: confirm zoning and lot-size minimums with the town, check whether the parcel needs an NHDES sub-5-acre subdivision approval, budget for a state-permitted septic designer's site evaluation, and check shoreland status if any water is nearby. All deeds for the entire county, regardless of which town, record at the single Hillsborough County Registry of Deeds in Nashua.