In short
Sections 8.1.4.3 and 8.1.4.4 of Joint Regulation No. 9473 are what answer a multifamily project’s most frequent question: how many units fit and how many metres may be built. The number of basic dwelling units to be permitted is determined on the basis of the lot’s total area, with two separate tables and with a minimum and a maximum column. In districts R-B, R-I and R-U: lots of two thousand square metres or less, between two hundred and twenty and one hundred and twenty-five square metres per unit; over two thousand, between one hundred and ninety and one hundred; over three thousand eight hundred, between one hundred and seventy-five and ninety-five; and over five thousand four hundred, between one hundred and sixty and ninety. In districts RT-I and RT-A the figures are higher: two hundred and sixty-five to one hundred and fifty up to two thousand metres; two hundred and fifty to one hundred and twenty-five over two thousand; one hundred and ninety to one hundred over three thousand eight hundred; and one hundred and seventy-five to ninety-five over five thousand four hundred. The gross floor area follows the same size scale and is the same for all five districts: one hundred per cent up to two thousand square metres, one hundred and twenty over two thousand, one hundred and forty over three thousand eight hundred and one hundred and sixty over five thousand four hundred. Two closing rules matter as much as the tables: if the lot is later lotified into two or more lots, the units are shared in proportion to each one’s net residential area; and where a Land Use Plan or a Territorial Plan is in force, the density will be in accordance with the minimum established in that document.
What is it?
They are the two sections of Rule 8.1.4 of Chapter 8.1 of Joint Regulation No. 9473 that set the intensity of an apartment-house project in districts R-B, R-I, R-U, RT-I and RT-A. Section 8.1.4.3 brings the population density in square metres of lot per basic dwelling unit, with one table for the residential districts and another for the tourist ones, and in both with a minimum and a maximum figure. Section 8.1.4.4 brings the gross floor area as a percentage of the lot’s total area. The same rule’s other parameters — lot size and width, occupation, yards, separations, accessories, loading and unloading and projections — are in this site’s companion guide.
Who can do it?
The tables apply to apartment-house projects in districts R-B, R-I, R-U, RT-I and RT-A. The first density table applies in districts R-B, R-I and R-U; the second, in RT-I and RT-A. The gross floor area table applies to all five districts. The lotification-sharing rule applies where the lot considered for an apartment-house project is later lotified into two or more lots. And where a Land Use Plan or a Territorial Plan is in force, the density will be in accordance with the minimum established in that document.
Requirements
- Determining the number of basic dwelling units to be permitted on the basis of the lot’s total area.Verified against the official source
- In districts R-B, R-I and R-U: a density of two hundred and twenty to one hundred and twenty-five square metres per unit on lots of two thousand square metres or less; one hundred and ninety to one hundred over two thousand; one hundred and seventy-five to ninety-five over three thousand eight hundred; and one hundred and sixty to ninety over five thousand four hundred.Verified against the official source
- In districts RT-I and RT-A: a density of two hundred and sixty-five to one hundred and fifty square metres per unit on lots of two thousand square metres or less; two hundred and fifty to one hundred and twenty-five over two thousand; one hundred and ninety to one hundred over three thousand eight hundred; and one hundred and seventy-five to ninety-five over five thousand four hundred.Verified against the official source
- That the gross floor area not exceed the maximum percentage of the lot’s total area: one hundred per cent up to two thousand square metres, one hundred and twenty over two thousand, one hundred and forty over three thousand eight hundred and one hundred and sixty over five thousand four hundred.Verified against the official source
- That in no case the gross floor area of any storey above the first exceed the maximum permitted occupation percentage.Verified against the official source
- If the lot is later lotified into two or more lots: computing each lot’s units as the proportion between the new lot’s net residential area and the total net residential area of the lot originally considered, multiplied by the total units permitted on it.Verified against the official source
- Where a Land Use Plan or a Territorial Plan is in force: applying the density in accordance with the minimum established in that document.Verified against the official source
Documents you need
Information pending verification.
Cost
Step by step
Step 1: Density is counted the opposite way round
It helps to understand the unit of measure before looking at the tables. Density is expressed not in units per lot but in square metres of lot per basic dwelling unit. That is why a lower figure means more units: if the density is one hundred square metres per unit, a four-thousand-square-metre lot yields forty units; if it is two hundred, it yields twenty. The regulation says the number of basic dwelling units to be permitted is determined on the basis of the lot’s total area. And each row carries two figures: a minimum and a maximum.
Step 2: The table for districts R-B, R-I and R-U
Four rows by lot size, in square metres per basic dwelling unit, with the minimum and maximum columns. Lots less than or equal to two thousand square metres: two hundred and twenty and one hundred and twenty-five. Over two thousand: one hundred and ninety and one hundred. Over three thousand eight hundred: one hundred and seventy-five and ninety-five. Over five thousand four hundred: one hundred and sixty and ninety. The pattern is the regulation’s usual one: the larger the lot, the fewer metres needed per unit — that is, the more intensity allowed.
Step 3: The table for districts RT-I and RT-A
The same size scale, with higher figures — that is, with fewer units permitted. Lots less than or equal to two thousand square metres: two hundred and sixty-five and one hundred and fifty. Over two thousand: two hundred and fifty and one hundred and twenty-five. Over three thousand eight hundred: one hundred and ninety and one hundred. Over five thousand four hundred: one hundred and seventy-five and ninety-five. The difference shows most on small lots: on a fifteen-hundred-square-metre lot, the maximum column gives twelve units in R-B, R-I or R-U and ten in RT-I or RT-A. On large lots the two tables nearly converge.
Step 4: Gross floor area, the same for all five districts
Section 8.1.4.4 opens by saying the gross floor area shall not exceed the maximum percentage of the lot’s total area under the table, and adds the condition repeated throughout the chapter: in no case shall the gross floor area of any storey above the first exceed the maximum permitted occupation percentage. The table is a single one for all five districts and follows the same size scale. Lots less than or equal to two thousand square metres: one hundred. Over two thousand: one hundred and twenty. Over three thousand eight hundred: one hundred and forty. Over five thousand four hundred: one hundred and sixty. A note on the source: this table’s column heading is damaged in the printing and contains the word "METROS", but the section’s own opening sentence says the figures are a maximum percentage of the lot’s total area; we publish them as percentages and record the heading.
Step 5: What happens if the lot is lotified later
This is the rule that stops a project from multiplying its units by splitting the lot. If the lot considered for an apartment-house project is later lotified into two or more lots, the number of basic dwelling units to be permitted on each lot will equal the proportion between the new lot’s net residential area and the total net residential area of the lot originally considered, multiplied by the total basic dwelling units permitted on it. In other words, the units are shared in proportion; they are not recomputed from scratch with the table. A note: the section does not define what the net residential area is; that must be looked up outside these two sections.
Step 6: Converting units and the municipality’s plan
Two provisions close the density section. The first: converting the number of dwelling units into a greater or lesser number of units is permitted under Section 6.1.1.6 of Volume VI, which is the one setting the equivalences in basic dwelling units — a studio is 0.4, one bedroom 0.6, two bedrooms 0.8 and three bedrooms 1.0. The second is the one that most surprises in practice: where a Land Use Plan or a Territorial Plan is in force, the density will be in accordance with the minimum established in that document. That is, the municipality’s plan can displace the regulation’s table.
Where to do it
These tables are applied within the construction permit or Permiso Único process before OGPe, an Authorised Professional, the Junta Adjudicativa or an Autonomous Municipality with Hierarchy I to III. The property’s qualification decides which of the two density tables applies, and is read on the Planning Board’s qualification maps. And if the municipality has a Land Use Plan or a Territorial Plan in force, the minimum density that document establishes must be consulted, because the regulation makes it prevail.
How long it takes
What to do if something goes wrong
The most frequent mistake is reading the table as if it gave units: it does not, it gives square metres of lot per unit. To get the number of units, divide the lot’s total area by the figure, and the row’s lower figure — the maximum column — is the one that produces more units. The second mistake is stopping at the first row: the scale changes on passing two thousand, three thousand eight hundred and five thousand four hundred square metres, and those jumps can justify buying a little more land. The third is mixing tables: the R-B, R-I and R-U one is not the RT-I and RT-A one, and the difference is large on small lots. On gross floor area, the scale is the same but single for all five districts, and remember the cap on each storey above the first, which may not exceed the maximum occupation percentage. Before settling the number, two checks save trouble: if the municipality has a Land Use Plan or a Territorial Plan in force, the density will be the minimum that document establishes; and if the lot is to be lotified later, the units are not recomputed with the table but shared in proportion to each new lot’s net residential area. And if the units will not all be three-bedroom ones, convert them to basic units under Section 6.1.1.6 before counting.
Common mistakes
- Reading the table as if it gave units per lot, when it gives square metres of lot per basic dwelling unit.
- Using the minimum column believing it is the maximum number of units, when the row’s lower figure is the one that produces more units.
- Applying the two-thousand-square-metres-or-less row to a larger lot, ignoring the jumps at two thousand, three thousand eight hundred and five thousand four hundred.
- Using the R-B, R-I and R-U table in an RT-I or RT-A district, or the reverse.
- Counting each flat as one basic dwelling unit without Section 6.1.1.6’s conversion by number of bedrooms.
- Ignoring that where a Land Use Plan or a Territorial Plan is in force, the density will be in accordance with the minimum established in that document.
- Recomputing the units with the table after lotifying the lot, when they are shared in proportion to each new lot’s net residential area.
- Applying the one hundred and sixty per cent gross floor area to a three-thousand-square-metre lot, when that figure starts over five thousand four hundred.
- Designing a storey above the first with a gross floor area greater than the maximum permitted occupation percentage.
- Looking in these sections for the yards, the occupation or the separations between buildings, which are in Sections 8.1.4.2, 8.1.4.5, 8.1.4.6 and 8.1.4.7.
Frequently asked questions
How many flats fit on a three-thousand-square-metre lot?
It depends on the district and on which column applies. In R-B, R-I and R-U, a lot over two thousand square metres has a density of between one hundred and ninety and one hundred square metres per basic dwelling unit; three thousand divided by one hundred gives thirty units and by one hundred and ninety gives fifteen. In RT-I and RT-A the same row is two hundred and fifty to one hundred and twenty-five, that is, twelve to twenty-four units.
Why does the table give metres and not units?
Because the density is expressed in square metres of lot per basic dwelling unit. The number of units to be permitted is determined on the basis of the lot’s total area divided by that figure, which is why a lower figure means more units.
What gross floor area do I have?
By lot size, the same in all five districts: one hundred per cent on lots less than or equal to two thousand square metres, one hundred and twenty over two thousand, one hundred and forty over three thousand eight hundred and one hundred and sixty over five thousand four hundred. In no case shall the gross floor area of a storey above the first exceed the maximum permitted occupation percentage.
What happens to my units if I later lotify the lot?
They are shared. The number of basic dwelling units to be permitted on each lot will equal the proportion between the new lot’s net residential area and the total net residential area of the lot originally considered, multiplied by the total units permitted on it.
Does this table govern, or my municipality’s plan?
The plan. The regulation says expressly that where a Land Use Plan or a Territorial Plan is in force, the density will be in accordance with the minimum established in that document.
Official sources
These are the government pages this guide is based on.
- Junta de Planificación de Puerto Rico (JP)
Junta de Planificación
docs.pr.gov
- Planning Board
jp
jp.pr.gov
- OGPe Single Business Portal
ogpe
www.permisos.pr.gov
Last verified
September 6, 2026
MiPRFácil is an independent informational website and is not affiliated with, endorsed by, or operated by the Government of Puerto Rico or any government agency.
MiPRFácil does not submit applications on your behalf.
Was this guide helpful?
Did you find out-of-date information?
Apartment houses: yards, separation between buildings and loading bay
Fifty per cent occupation, yards of three metres or one fifth of the height, and one loading space per forty units above fifteen.
If your lot is smaller than the district requires: the tables that do apply
How much may be occupied, what rear yard is left and when you may build up to the boundary, plus the conversion to basic dwelling units.
Terraced houses: six units per building, ten if the façade changes
A 150-square-metre minimum lot, six metres of frontage per unit, and the front yard that rises to six metres if there is no parking on the lot.
Residential districts R-B, R-I and R-U: what can be built and to what measurements
The minimum lot, width, occupation, density and yards of the three residential districts, and the uses that come only by exception.
Master Plan: how it is filed, adopted and how long it lasts
Twelve initial contents, twelve filing requirements, a public hearing, a Governor’s Executive Order and five years’ validity.
Changing a lot’s qualification: maps, maximum sizes and effective dates
Table 7.1’s maximum sizes by district, what is filed, and the fifteen days from publication to effect.