The information contained in this article is not intended as legal advice and may no longer be accurate due to changes in the law. Consult NHMA's legal services or your municipal attorney.
What do you call a land use (activity or structure) that was legal when it began but that would not be allowed to begin today because local land use ordinances or regulations have changed? In the past, we might have referred to this as a “grandfathered use.” A better and more accurate way to refer to it is as a “legally pre-existing nonconforming use.”
Planning boards, zoning boards of adjustment, building inspectors, selectmen, code enforcement officers—all may be called upon from time to time to determine whether certain land uses are allowed, whether they may continue, and in what form. Often, these officials are met with the assertion that a building or activity existed before the rules changed and therefore must be allowed to continue.
Is this true? If it is, what does that mean? Can local officials regulate a legally pre-existing use at all? Or, is it time to throw up our hands and walk away? This article attempts to explain what a legally pre-existing nonconforming use really is, and to dispel a few of the most common myths about how it works. Admittedly, many aspects of this subject are complex and have no simple solutions. There are far more questions than there are answers. However, a firm understanding of the basic meaning of the term is a great place to begin.
Myth #1: There is a law somewhere saying “thou shall not touch a legally pre-existing nonconforming land use."
Sort of, but it isn’t that simple. Legally pre-existing nonconforming uses of land are protected from many later-enacted prohibitions, but it doesn’t work in every situation.
This kind of protection balances the private property rights of land owners against the public need to regulate land use. Both the New Hampshire Constitution and state land use laws protect property owners by prohibiting the government from unreasonably depriving them of a vested right to use their property. See N.H. Const. pt. I, arts. 2, 12; Hampton v. Brust, 122 N.H. 463 (1982); RSA 674:19. When the government does unreasonably deprive an owner of a vested right, we say that a “taking" has occurred, and the Constitution requires the government to compensate the property owner reasonably for that loss. Quite understandably, governments would like to avoid this scenario if possible. Thus, the law provides that a “zoning ordinance adopted under RSA 674:16 shall not apply to existing structures or to the existing use of any building." RSA 674:19.
In other words, zoning ordinances and land use regulations are not supposed to be retroactive; they usually apply only to new or altered uses of land going forward. However, this protection is not absolute. “A use of land which, at the time a restriction on that use went into effect, was established (or ‘vested’), and has not been discontinued or abandoned, can continue indefinitely, unless it includes activity which is a nuisance or harmful to the public health and welfare; but the use cannot be changed or substantially expanded without being brought into compliance." Cohen v. Henniker, 134 N.H. 425, 427 (1991). This is, in a nutshell, the law of legally pre-existing nonconforming uses.
The questions to ask are: (1) did the use lawfully exist at the time the restriction was adopted, and (2) has it continually existed since that time? See, for example, Dartmouth Corp. of Alpha Delta v. Town of Hanover, 169 N.H. 743 (2017); Seabrook v. Vachon Mgmt, Inc., 144 N.H. 660 (2000); Derry v. Simonsen, 117 N.H. 1010 (1977). The nonconformity might be the type of activity (e.g., residential use, retail store, wedding venue, short-term rental) or a type of dimensional factor (e.g., setbacks, size restrictions, frontage). It is not enough for a landowner to have constructed a building or conducted an activity before local zoning would have restricted it; those activities also had to be lawful at the time they occurred or began. See Monadnock Rod & Gun Club v. Town of Peterborough, 177 N.H. 70 (2024).
For example, assume Joe Smith built his home 20 feet from the street in 2015. The zoning ordinance required a minimum 20-foot setback at that time, so he was in compliance. If the ordinance had been amended in 2025 to require a 25-foot setback from the front property line, Mr. Smith’s home generally would have been protected from that tighter restriction because (a) the house met the setback requirement when it was built, and (b) it had continued to exist in place since that time. If either of those two pieces had been missing, however, the house might have been in violation of local zoning and not protected. If, say, Mr. Smith had built his house only 15 feet from the street in 2015, it would have violated the ordinance from the start. Since the house would not have been “lawfully existing" when the ordinance was amended to increase the setback to 25 feet, the house probably would have no protection from the new requirement. See Quirk v. Town of New Boston, 140 N.H. 124 (1995).
Myth #2: The owner of a legally pre-existing nonconforming structure or activity can continue that use in any way they want to.
Not necessarily. The right to continue a nonconforming activity or maintain a nonconforming structure may continue for quite a long time in some cases, but there are at least two significant limitations.
First, if the use is abandoned, it may be lost. “Abandonment" happens when the owner (a) intends to abandon or relinquish the use, and (b) takes some overt act, or fails to act, in some way that implies that the owner neither claims nor retains any interest in that use. See Lawlor v. Salem, 116 N.H. 61 (1976). For example, a grandfathered pig farm was abandoned (and the right to use it as a pig farm was lost) when the farmer sold all his pigs (an overt act). Salem v. Wickson, 146 N.H. 328 (2001). The use might also be abandoned if the structure is destroyed and the owner waits decades to replace it (fails to act). These are easy examples; most real-world situations are more complex and depend upon all the facts involved. The question can become quite difficult when the use is terminated involuntarily (such as when a building burns down) or only temporarily (a business is closed but the owner intends to reopen after remodeling or obtaining additional financing). The local zoning ordinance might also define what “discontinuance” or “abandonment” of a nonconforming use means, which can help to answer the question. See, for example, Pike Industries v. Woodward, 160 N.H. 259 (2010).
In addition, some local ordinances include a specific time period within which a use must be re-established to avoid abandonment (a “use-it-or-lose-it" provision). The New Hampshire Supreme Court has upheld a zoning ordinance under which a nonconforming structure is considered abandoned if it has not been replaced within one year after being destroyed. McKenzie v. Eaton, 154 N.H. 773 (2007). However, in a separate opinion, one justice indicated that this sort of provision might constitute a “taking" for which an owner must be compensated, and that if the question is presented to the Court that way in the future, the result might be quite different.
Second, the idea behind the concept of legally pre-existing nonconforming uses is to permit property owners to keep what they have where they have it, but tightly control expansion or extension of that use. RSA 674:19 states that a zoning ordinance “shall apply to any alteration of a building for use for a purpose or in a manner which is substantially different from the use to which it was put before alteration." For example, the footprint of a building that already violates setback requirements generally may not be expanded unless the owner obtains a variance, even if it was legal when built. See, for example, Shopland v. Enfield, 151 N.H. 219 (2004). Likewise, construction of additional floors on a nonconforming building may also be a prohibited extension even if there is no expansion of the building’s footprint. Granite State Minerals, Inc. v. Portsmouth, 134 N.H. 408 (1991).
Closer questions may arise when an owner wishes to change or expand the scope of an activity or structure. Even if the new use would be less nonconforming than the original use, if the zoning ordinance does not permit that activity in that district, the change may not be allowed if the new use is “substantially different" from the original use. However, natural expansion of a nonconforming use may be allowed, but “enlargement or expansion may not be substantial and may not render premises or property proportionally less adequate.” New London Land Use Assoc. v. New London Zoning Board, 130 N.H. 510, 516 (1988). The expansion must also not be so great that it really amounts to an entirely new use. Courts will look at whether: (a) the expansion reflects the nature and purpose of the original nonconforming use; (b) the expansion is merely a different manner of exercising the same use and is not different in character, nature and kind; and (c) the expansion will have a substantially different effect on the neighborhood. See Dovaro 12 Atl., LLC v. Town of Hampton, 158 N.H. 222 (2009); Severance v. Epsom, 155 N.H. 359 (2007).
The terms of the zoning ordinance are also very important. For example, in the Severance case, the Town’s zoning ordinance did not distinguish between seasonal and year-round residential use. As a result, a legally pre-existing nonconforming seasonal home could be converted into a year-round home. Zoning ordinances might also define what constitutes a “substantial change in use" of a grandfathered structure or use. The lesson? Zoning ordinances should be carefully drafted to reflect what the municipality really intends to do.
Myth #3: The owner of a substandard lot (smaller than current zoning allows) has a protected right to use it for any purpose or structure allowed in that district.
This is not true. Remember from Myth #1, the law protects lawfully pre-existing nonconforming uses. A vacant lot may have existed before zoning made it substandard, but it isn’t being “used" yet. This means the lot can continue to exist, but the owner is not protected from the operation of other land use provisions. There are three ways an owner might build on a substandard lot. The first and most straightforward is if there is a “lot of record" savings clause in the zoning ordinance. These clauses exempt pre-existing lots from later-enacted frontage and/or lot size requirements, or in some cases, allow buildings on those lots by special exception. If there is a savings clause, then the owner can exercise whatever rights that clause provides for substandard lots. (Here again, the terms of the ordinance are really important.)
If there is no savings clause in the ordinance, then the owner must obtain a variance from the zoning board of adjustment (ZBA) as well as whatever other approvals that municipality normally requires to build any structure on a substandard lot. The purpose of a variance is to protect the Constitutional rights of the owner by preventing them from being deprived of the viable economic use of the property. However, even the Constitution does not provide that every lot, regardless of size, must support at least one single-family home. The ZBA must apply the five variance criteria to determine whether the variance is appropriate for that particular lot under all of the facts and circumstances. For example, an owner of a substandard shorefront lot was denied a variance for a seasonal home because there was no adequate place for a septic system. Carter v. Derry, 113 N.H. 1 (1973).
Third, the owner may still be able to build if the lot is part of a vested subdivision, which brings us to…
Myth #4: An owner with planning board approval is protected from later changes in zoning ordinances or regulations.
This is only true if the owner meets some conditions. A lot that is (a) part of an approved and recorded subdivision may be protected from later changes in local zoning if (b) “active and substantial construction" has begun on the project within 3 years after the approval, and if (c) the project is also “substantially completed" within 7 years after approval. RSA 674:39; Chasse v. Candia, 132 N.H. 574 (1989). These rights can also be passed on to subsequent owners of the lots. Morgenstern v. Rye, 147 N.H. 558 (2002). Of course, as with everything else involving nonconforming uses, it is slightly more complicated than that. A vested subdivision or site plan only provides protection for the actual lot divisions and other specific improvements that are part of the approved plan (not every possible use that was allowed at the time of the original approval). In addition, if the subdivision plan was never recorded, as happens from time to time, then RSA 674:39 does not protect the owner. Such an owner might find themselves in limbo between RSA 676:12 (protecting some applicants from proposed zoning changes) and RSA 674:39 (protecting those who have received approval and have recorded the plan). Furthermore, even lawfully pre-existing nonconforming properties are not protected from later-enacted or increased impact fees. RSA 674:39.
Myth #5: Lawfully pre-existing nonconforming properties are immune from all other local regulation.
This is a very common misconception. Although a lawfully pre-existing nonconforming land use may generally continue, there are several ways in which it may be impacted by later-enacted restrictions.
Local Approvals: We explained in Myth #2 that a nonconforming use might be allowed to expand in a few very narrow circumstances. However, even if expansion is allowable, the owner is still required to obtain all other local approvals that are required for that particular expansion project, such as site plan approval, a building permit, septic or driveway approval. See Bio Energy, LLC v. Hopkinton, 153 N.H. 145 (2005).
State Fire Code: Unlike zoning ordinances and regulations, the State Fire Code can apply to existing buildings, plants or equipment, which were not previously but then become used for flammable liquids, and to existing buildings, plants, structures or equipment now used for flammable liquids when the state fire marshal determines the conditions constitute a fire hazard. RSA 153:5. It also applies to new construction, additions and alterations that might be permitted under zoning as an expansion of a legally pre-existing nonconforming use/structure, but which the State Fire Code may not permit. Even a lawfully pre-existing nonconforming building which is otherwise protected from local zoning changes but which presents a condition that is hazardous to life or property may have to be modified within a “reasonable time" as determined by the State Fire Marshal to bring it into compliance with the fire code. See RSA 153:14.
Driveway Regulation: No property owner has the legal right to maintain a driveway access that constitutes a potential threat to the integrity of a public road or to the safety of the public on that public road. RSA 236:13, VI gives planning boards “continuing jurisdiction over the adequacy and safety of every existing driveway, entrance, exit, and approach to a [municipal] highway" regardless of whether the driveway ever received planning board approval. Property owners have continuing responsibility for driveway connections to municipal highways, including grades, culverts and any other related structures that impact the public road, whether they are located within the highway right of way or outside of it. It may come as a surprise to property owners that the planning board has the authority to order the owner to make any repairs or otherwise modify a driveway (even one that has existed since before RSA 236:13 was enacted) if it “is or becomes a potential threat to the integrity of the highway or its surface, ditches, embankments, bridges or other structures, or a hazard to the safety of the traveling public."
Myth #6: Municipalities cannot regulate legally pre-existing junkyards.
Yes, they can, and more importantly, they should. While there are many ways to define “junkyard," in this case we refer to a junkyard under RSA 236:112. Since 1965, this law has required municipalities to license junkyards, including motor vehicle junkyards and salvage yards, machinery junkyards and other similar collections of material (even if they are not businesses).
There are two parts to a local junkyard license: initial approval of the location, and ongoing approval of the operation. If a yard existed before 1965, it is generally protected under the junkyard statute as to its location. RSA 236:125. However, regardless of when a yard was established, it must continue to comply with all other operational requirements under this statute, including, among other things, the Best Management Practices (BMPs) for the automobile salvage industry established by the NH Department of Environmental Services. RSA 236:115, :121. Owners must obtain a license from the municipal governing body and must renew it annually, certifying that they are in compliance with the latest BMPs and all operational conditions. In other words, a junkyard owner may have a vested right to continue the operation where it is, but not a vested right to any particular manner of operation.
In addition, junkyards are also subject to local zoning regulation. Municipalities may prohibit junkyards through local zoning, but lawfully pre-existing junkyards are protected from later-enacted restrictions in the same way as other pre-existing land uses, and expansion and modification of those junkyards are similarly limited. Difficult questions may arise when a junkyard owner is required to change its operations to comply with the ongoing local licensing conditions and the BMPs (for instance, building a structure to store certain hazardous fluids safely), but finds that local zoning prohibits such a structure in that location. As with all nonconforming use issues, often there are more questions than answers in these situations.