Who can build an extra floor on top of an apartment building in Peru? Air rights, extra storeys and basements

The short answer: the internal regulations decide

In a building under Peru’s regime of private and common ownership (propiedad exclusiva y común), adding a floor on top (sobreelevación) or digging below does not depend on who lives closest. It depends on who owns the air rights (aires), the roof terrace (azotea) or the basement (sótano). The building’s internal regulations (reglamento interno) or the owners’ title deeds settle that. If they are silent, the default is that these are common property.

This page covers only that question. How the owners’ association (junta de propietarios) works and votes in general is in our guide on the owners’ association and common expenses. What else the regulations can impose is in internal regulations of a building.

What «aires» means

None of the norms we read defines air rights in one sentence. They do say what can be done with them. The regulation of Ley 27157 counts them as a property unit:

«Unidades Inmobiliarias: Son los terrenos sin edificar, las edificaciones, los aires o las secciones de cualquiera de ellos que sean factibles de independizar […]» — D.S. 035-2006-VIVIENDA, article 2

(Property units are undeveloped land, buildings, air rights, or parts of any of them that can be given their own registry file.)

In practice, the air rights are the space above the top roof where new floors could go. Holding them means holding the right to build there.

The starting point is the Civil Code. Article 954 says ownership of a plot «se extiende al subsuelo y al sobresuelo» (extends to the subsoil and the space above). In a building the land is common property (article 40 of Ley 27157 and article 134 of its regulation). It follows, although it is not written in those words, that what lies above and below starts out belonging to everyone.

If the regulations say nothing: the air rights are common

Ley 27157 does not mention air rights. It mentions roof terraces and basements:

«h) Los sótanos y azoteas, salvo que en los títulos de propiedad de las secciones aparezcan cláusulas en contrario;» — Ley 27157, article 40

(Basements and roof terraces are common, unless the unit title deeds contain clauses to the contrary.)

Sunarp, the property registry, reads that rule as covering air rights. Its Directiva N.° 009-2008-SUNARP/SN says:

«De conformidad con el artículo 40, inciso h), de la ley 27157 los aires se reputan zonas comunes, salvo que en los títulos de propiedad de las secciones aparezcan clausulas en contrario por las cuales se les atribuya la condición de sección de propiedad exclusiva.» — Directiva N.° 009-2008-SUNARP/SN, section 5.7

(Air rights are deemed common areas unless the unit deeds contain clauses making them a private unit.)

What this means for you:

• If you own the top-floor flat and neither your deed nor the regulations give you the air rights, they are not yours. They belong to all owners.
• Building above is work on common property. Article 136 of the regulation requires «autorización expresa de la Junta de Propietarios» (express approval of the owners’ association), by a qualified majority if the work changes or limits the use of that property, plus a permit.
• Selling or transferring the air rights disposes of common property. Article 135 requires the vote of «cuando menos las dos terceras partes de los propietarios» (at least two thirds of the owners).

Also, roofs and structural elements serving two or more units are non-transferable common property unless the regulations say otherwise (article 134, letter b). Any new floor rests on them.

If the regulations reserved the air rights: they belong to the holder

Developers or original owners often reserve the air rights in the internal regulations. The Reglamento de Inscripciones del Registro de Predios allows that reservation to be registered in two ways:

«Cuando en el Reglamento Interno se establezca la reserva de aires de la edificación, ésta podrá independizarse como sección de dominio exclusivo siempre que se le asigne porcentaje de participación de los bienes comunes. En este caso la independización procederá, siempre que cuente con área proyectada de acceso. El Reglamento Interno puede establecer reserva de aires sin independización […]» — Reglamento de Inscripciones del Registro de Predios, article 63

(A reservation of air rights can get its own file as a private unit if it is given a share of the common areas and has a planned access area; it can also be recorded without its own file.)

Once made, the association cannot remove it alone. Sunarp’s Directiva says changing it «requerirá necesariamente el consentimiento del respectivo titular, además del acuerdo de modificación del reglamento interno» (necessarily requires the holder’s consent, besides the vote to amend the regulations) (section 5.11).

If someone buys those air rights, the transfer is registered «siempre que se constituya reglamento interno y se adjunten planos de independización y memoria descriptiva autorizada por ingeniero o arquitecto colegiado» (section 5.6): there must be internal regulations, plus subdivision plans and a technical description signed by a registered engineer or architect.

If the regulations forgot to reserve them

This happens often: the developer meant to keep the air rights, but the regulations never said so. The Directiva gives a way out:

«Para efectos registrales la clausula en contrario consta en el reglamento interno, o en una modificación posterior en el que se apruebe el acto de reconocimiento de la propiedad preexistente de los aires, y que había sido omitida en la declaración inicial del reglamento interno. Para ello se requiere la votación favorable de 2/3 del porcentaje de participación de los propietarios.» — Directiva N.° 009-2008-SUNARP/SN, section 5.7

(A later amendment can recognise the pre-existing ownership of the air rights that the original regulations left out, with a favourable vote of 2/3 of the owners’ participation percentage.)

There is a limit. If the regulations expressly declared the air rights common, that is not an omission: article 135 of D.S. 035-2006-VIVIENDA (disposal of common property) applies, «salvo que el reconocimiento de la propiedad preexistente se realice por unanimidad de los propietarios» (unless the recognition is unanimous).

Watch how votes are counted. Article 135 speaks of two thirds «de los propietarios» (of the owners). The Directiva speaks of 2/3 «del porcentaje de participación» (of the participation percentage). In a building with flats of very different sizes, those are not the same. Your regulations may set their own rules; read them before voting.

Even if the air rights are yours, you need a permit and the association’s input

Holding the air rights does not exempt you from building rules. Article 133 of the regulation of Ley 27157 says:

«Tratándose de ejecución de obras, deberán obtener previamente la Licencia de Obra de la municipalidad correspondiente y comunicar oportunamente su fecha de inicio a la Junta de Propietarios. Si la obra alterase la volumetría, el estilo arquitectónico o el aspecto exterior de la sección donde se ejecuta, o del inmueble matriz, el propietario deberá obtener previamente la aprobación de la Junta de Propietarios.»

(Before building you need the municipal permit and must tell the association when work starts; if the work changes the volume, style or exterior of the unit or the building, you need the association’s prior approval.)

A new floor almost always changes the building’s volume. Expect to go through the association even if the reservation is yours. The work also must not harm «las condiciones de seguridad y funcionamiento de la edificación» (the building’s safety and operation) or the rights of other owners.

What the municipality asks for today is in our guide on the building permit. If you already built without one, read building without a license.

Building downward (basements)

Ley 27157 treats basements the same as roof terraces: common unless the deeds say otherwise (article 40, letter h). Sunarp’s Directiva applies its air-rights rule, «en lo que fuese pertinente» (as far as relevant), to other areas that are common only because the regulations were silent (section 5.8). And the land is non-transferable common property unless agreed otherwise or a surface right (derecho de superficie) is created (article 134, letter a). Digging a new basement touches all of that, so the association and the permit come in just as they do for building up.

After building: the registry

Registering the new floor with Sunarp is a separate process this page does not cover. How the building declaration, internal regulations and unit subdivision fit together is in our guide on the building declaration, internal regulations and unit subdivision.

A new law that is not in force yet: Decreto Legislativo 1568

Decreto Legislativo 1568 (2023) creates a new horizontal-property regime, but it is not in force yet: as of 30 September 2026 its regulation has not been published. That is why this page applies Ley 27157 and its regulation. We explain what would change in «Possible changes ahead» below.

What this page does not cover

• How the Tribunal Registral or the courts have ruled on specific air-rights cases.
• Surface rights as another way to build on land you do not own.
• The technical requirements for the permit (structure, zoning parameters, maximum height).
• What Sunarp needs to register the extended building and the new floors.
• Municipal and registry fees.
• Quintas and complexes under the independización y copropiedad regime.
• How common expenses are shared once floors are added.