In short
Some homes and businesses exist legally even though today they do not comply with the district’s rules: these are legal non-conformities, and the Joint Regulation devotes a short chapter to them that settles many arguments. Three rules govern. First: if you discontinue a legal non-conforming use for more than two years, any future use of the property will have to conform to the district. Second: if the building is damaged and restoring it to its original condition costs more than fifty per cent of what replacing the whole structure would cost today, not counting the foundations, it may not be restored for the same purpose; if the damage was less than that fifty per cent, it may be restored, but within one year. Third: once the use conforms to the regulation through any change, it may not be devoted again to non-permitted uses. And what you may build depends on whether your non-conformity is of use, of density, or of something else.
What is it?
It is Chapter 2.4 of Joint Regulation No. 9473. A legal non-conformity is a property, building or use that was lawfully established but which today does not conform to the regulation in force for its district. The regulation allows permits to be issued for those non-conforming uses and buildings that are lawful, and provides that legal non-conformity permits will clearly state the nature and extent of the non-conformity in relation to which the building or property does not conform.
Who can do it?
It applies to non-conforming uses and buildings that are lawful, that is, those established under the rules of their time. The chapter distinguishes four situations according to what you are non-conforming in: conforming in use and population density but non-conforming otherwise; conforming in use but non-conforming otherwise; non-conforming in use and in population density; and retail shops of everyday household goods that are non-conforming in use in residential districts. There is one carve-out: legal non-conformity permits in School Zones are governed by Chapter 7.4 of Volume VII, which we did not read here.
Requirements
- That the non-conforming use or building be lawful, that is, established in accordance with law.Verified against the official source
- Not discontinuing the legal non-conforming use for a period longer than two (2) years.Verified against the official source
- That the established legal non-conforming use be determined necessary to serve the immediate sector.Verified against the official source
Documents you need
Information pending verification.
Cost
Step by step
Step 1: What it is and what the permit says
The regulation allows permits to be issued for those non-conforming uses and buildings that are lawful, considering the criteria the Joint Regulation itself specifies. And it adds a detail worth using: legal non-conformity permits will clearly state the nature and extent of the legal non-conformity in relation to which a building or property does not conform to the regulation. That is, the permit is not a generic pass: it says exactly where you fall short and how far. Keep that document, because it is the measure of what you may keep.
Step 2: The two years that change everything
This is the rule most people discover late, usually when trying to reopen. The regulation says: whenever a legal non-conforming use is discontinued for a period longer than two years, any future use of the property in question will conform to the provisions of this Regulation for the district in which it is located. In plain terms: if the business or use stands idle for more than two years, the protection is lost and whatever comes next must meet the district’s rules like any new project. There is no written exception in the chapter for closures through illness, works or lack of money: the text speaks of discontinuation, full stop.
Step 3: The one-way road
The other rule in the same section is short and final: once the use of a building or property conforms to the Regulation through any change, it may not be devoted again to non-permitted uses. If you turn the non-conforming premises into something that does comply with the district — even temporarily, even for convenience — you cannot go back. It is worth thinking twice before changing the use "in the meantime".
Step 4: The fifty per cent and the year to rebuild
Where a building devoted to a legal non-conforming use has been damaged, the question is what it costs to restore it to its original condition, as OGPe determines. If that cost exceeds fifty per cent of what it would cost today to replace the entire structure — not counting the foundations — the building may not be restored for the same purpose to the extent it was used. If the damage was less than that fifty per cent, the building may be restored for the same purpose and to the same extent, provided that restoration is carried out within one year of the damage occurring. Two details that decide cases: the calculation excludes the foundations, and it is OGPe that determines it, not the owner or the contractor. And the year runs from the damage, not from when you find the money.
Step 5: If you conform in use and density
This is the most favourable situation. For buildings conforming in use and population density but legally non-conforming in other respects, structural alterations, extensions and sanitary and kitchen installations are permitted, provided the proposed extension conforms in every respect to the regulation. That is: you may extend and add a bathroom and kitchen, but the new part must comply fully. The non-conformity stays where it is; it does not extend to what you build.
Step 6: If you conform only in use
For buildings or parts of buildings conforming in use but legally non-conforming in other respects, changing existing floors, roofs and interior walls for permanent materials is permitted. It is a licence to improve, not to grow: replacing what is already there with permanent material, yes; adding, is not in this item.
Step 7: If you are non-conforming in use and density
Here the regulation tightens. For buildings legally non-conforming in use and population density, alterations are permitted provided they involve no structural changes, no extensions, no increase in gross floor area or height, no sanitary or kitchen installations on the property, and no increase in the non-conformity as to use and population density. That is: maintaining and repairing, yes; growing, going up, or adding a bathroom or kitchen, no.
Step 8: The neighbourhood shop: the exception with a public hearing
The regulation makes room for a very Puerto Rican case. For buildings occupied or used as retail shops of everyday household goods, legally non-conforming in use in residential districts, alteration, reconstruction or horizontal extension in concrete or any other permanent material of the non-conforming part is permitted. But with conditions. Public hearings will be held to consider the project, meeting the regulation’s requirements. The exterior walls of the part being altered or rebuilt must be concrete or other permanent material, and yards no smaller than the existing ones must be kept in relation to those walls. Any horizontal extension must be for greater facilities of the existing use and meet the district’s other requirements. And there is a cap: the gross floor area to be occupied or used for the extensions shall be no greater than fifty per cent of the existing premises’ gross floor area.
Step 9: Two limits that close the chapter
The first closes a known shortcut: grouping lots will not be considered for building extensions to legal non-conforming uses. You cannot buy the lot next door and merge it to grow with the non-conformity in tow. The second is a substantive condition: it must be determined that the established legal non-conforming use is necessary to serve the immediate sector. That sentence is what supports the neighbourhood-shop exception and, conversely, what can defeat it if the use no longer serves anyone in the area.
Where to do it
Chapter 2.4 fixes criteria, not counters. Legal non-conformity permits and the works this chapter allows are processed through the Joint Regulation’s own permit system — OGPe, an Authorised Professional or the autonomous municipality with the corresponding hierarchy, as the case may be. It is OGPe that determines the restoration cost against the fifty per cent. And if your property is in a School Zone, the chapter refers you to Chapter 7.4 of Volume VII.
How long it takes
What to do if something goes wrong
If you have a legal non-conforming use and are going to close, count the days: past two years of discontinuation, any future use will have to conform to the district. If the building was damaged, do not start from the works budget but from the comparison the regulation makes: the cost of restoring it to its original condition against today’s cost of replacing the whole structure without the foundations; below fifty per cent you may restore for the same use, but you have one year from the damage. If you are going to build, first identify what you are non-conforming in, because the permit says so: conforming in use and density lets you extend and add a bathroom and kitchen if the new part complies; conforming only in use lets you change floors, roofs and interior walls for permanent material; non-conforming in use and density limits you to alterations with no structural changes, no extension, no increase in area or height and no sanitary or kitchen installations. If you have a corner shop selling everyday goods in a residential district, you may extend horizontally, but with a public hearing and a cap of fifty per cent of the existing gross floor area. Do not count on grouping lots to grow: the regulation excludes it. And bear in mind it must be determined that the use is necessary to serve the immediate sector. Three caveats: we publish no cost or timeframe because this chapter fixes none; cases in School Zones go under Chapter 7.4, which we did not read here; and the file the Board links is named "Reglamento Conjunto de Emergencia", but the document inside is Joint Regulation No. 9473 of 16 June 2023.
Common mistakes
- Closing the non-conforming business for more than two years and expecting to reopen it as before.
- Changing to a conforming use "in the meantime", losing the right to return to the previous one.
- Calculating the fifty per cent including the foundations, which the regulation excludes.
- Counting the year to restore from when the money is found rather than from the damage.
- Extending or adding a bathroom and kitchen in a building non-conforming in use and density.
- Extending the corner shop without the public hearing the regulation requires.
- Exceeding fifty per cent of the existing gross floor area in that extension.
- Buying and merging the next-door lot to extend a non-conforming use.
Frequently asked questions
How long can I close without losing the non-conformity?
Up to two years. The regulation says that whenever a legal non-conforming use is discontinued for a period longer than two years, any future use of the property will conform to the regulation’s provisions for the district in which it is located.
My building was damaged — can I rebuild it the same?
It depends on the damage. If restoring it to its original condition costs more than fifty per cent of what replacing the entire structure would cost today, not counting the foundations — as OGPe determines — it may not be restored for the same purpose. If the damage was less than that fifty per cent, yes, provided the restoration is carried out within one year of the damage.
Can I extend a non-conforming property?
It depends on what you are non-conforming in. If you conform in use and density, structural alterations, extensions and sanitary and kitchen installations are allowed provided the new part fully complies. If you are non-conforming in use and density, only alterations with no structural changes, no extension, no increase in area or height and no sanitary or kitchen installations.
What if I have a corner shop in a residential district?
Retail shops of everyday household goods that are non-conforming in use in residential districts may be altered, rebuilt or extended horizontally in concrete or other permanent material, with a public hearing, permanent exterior walls, yards no smaller than the existing ones, and a cap of fifty per cent of the existing premises’ gross floor area.
Can I merge my lot with the next one to grow?
Not for this. The regulation says expressly that grouping lots will not be considered for building extensions to legal non-conforming uses.
Official sources
These are the government pages this guide is based on.
- Oficina de Gerencia de Permisos (OGPe)
OGPe
docs.pr.gov
- Permit Management Office
ogpe
ogpe.pr.gov
Last verified
September 3, 2026
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