Extension, new storey or mansard on an existing house in Romania (2026): permit, expertise, steps

An extension, a new storey and a mansard that changes the roof shape need a building permit and a technical expertise of the existing house, and a firm has to build them, not you. What can still go on a notification, which plot limits remain, what a SIP storey brings, and what follows the works.

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Published: November 3, 20267 min read

The short answer: a ground-floor extension, a new storey and a mansard that changes the roof shape are interventions on an existing building and need a building permit (Law 169/2026, art. 372 and art. 245). The project must rest on a technical expertise of the house (art. 437 para. 2 let. a), and you may not build it yourself (art. 285 para. 1).

The notification route for a house of up to 150 m² is for new houses only, not for extensions. Below are the works that can still go on a notification, the steps for the permit and what changes afterwards.

What work you are doing and which regime applies

Work	Regime	Where it is written
Roof repairs without changing its shape and look	No formality	Art. 299 para. 2 let. a point 2
Roof replaced in the same shape, or reconfigured and raised by at most 0.50 m, within the heights of the urban plan	Notification	Art. 294 para. 2 let. b point ii
Mansard fitted out in the existing loft, without changing the volume and without strengthening	Notification	Art. 294 para. 2 let. b point iii
Bathroom or technical room of at most 25 m²	Notification	Art. 294 para. 2 let. b point x
Ground-floor extension	Building permit	Art. 372 para. 2 let. d; art. 245 and 294
New storey	Building permit	Art. 372 para. 2 let. e; art. 245 and 294
Mansard with a change of roof shape	Building permit	Annex 1 to the Code

The Code calls an extension work that enlarges the house’s footprint and volume, and a supraetajare the addition of a whole or partial storey while keeping the entire existing building. If you do not keep the house whole, the intervention counts as partial demolition and rebuilding. When you change the roof shape to turn the loft into a mansard, the work is called mansardare (art. 372 para. 2 let. d, e and l).

The notification works in the table are allowed only outside protected built-up zones. On a notification, tacit approval comes 15 working days after filing, and works may start 15 calendar days after it (art. 296).

The alternative: a separate building

In the countryside, inside the built-up area and outside metropolitan zones, a separate outbuilding can be the easier route: garages, covered terraces, summer kitchens and other outbuildings totalling no more than 50 m² go on a notification (art. 294 para. 2 let. a point i). Temporary outbuildings of at most 20 m² and at most 2.5 m high, without a foundation, demountable and on a wood or metal structure, need no formality at all, but are declared for tax (art. 299 para. 2 let. c and para. 12). A room joined to the house, however, is not an outbuilding but an extension.

Technical expertise: mandatory, even for a light storey

A technical expertise of the existing house is mandatory for any intervention project and for assessing the work’s effect on the neighbours (art. 437 para. 2 let. a and d). Only a certified technical expert may do it, within the fields of their certificate, and the conclusions go into the house’s technical book (art. 437 para. 4 and art. 439). The permit project also includes, where relevant, a measured survey of the existing house (art. 282 para. 1).

If the intervention significantly changes how the structure works, as a new storey may, the expertise is a general one. In zones with a ground acceleration of at least 0.15 g, it also sets the seismic risk class of the house in its proposed form (Annex 2 to the Code, point 1.4.4).

A storey made of SIP panels is light, so it loads the old house and its foundation less; what low mass means in an earthquake is covered in our guide to earthquake resistance. Low weight does not exempt you from the expertise, though: how much the house can take and what strengthening it needs is the expert’s call, not the material’s.

Besides the expertise, an energy audit may be needed (art. 285 para. 2). Interventions must stay within the maximum energy use allowed by the technical rules (art. 402 para. 1). If the works on the envelope and/or the building services cost more than 25% of the house’s taxable value, land excluded, the law treats them as a major renovation, with energy performance requirements (Law 372/2005, art. 3 point 9 and art. 11).

The plot limits still apply

The enlarged house must fit the zone’s planning rules: POT, CUT, height and setbacks from the plot boundaries are in the urban planning certificate and come from the local regulation, not from the Code (art. 245 para. 1 and art. 314 para. 5). A mansard counts as a storey, its usable area counts toward the CUT, and new mansards are allowed only where the local planning regulation permits them. The one exemption: if you fit out the existing loft without changing its geometry and that takes you over the CUT, you do not need a zonal plan (PUZ) (Annex 1 to the Code).

The Code requires the neighbours’ consent, as a notarised act, only when the expertise shows the work needs safety measures on their buildings (art. 261). Separately, the Civil Code requires at least 60 cm between a building and the boundary, unless the local regulation says otherwise, and at least 2 m for a window or balcony overlooking the neighbour’s land; a shorter distance can be agreed only by a notarised act with the neighbour (art. 612 and art. 615).

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Who builds and who checks

You may not build an extension or a new storey yourself, even if you built the house yourself: for existing buildings, the law allows self-build only for maintenance and routine repairs (art. 285 para. 1). Insurance for the works is mandatory, but an owner who lives in the house is exempt for one intervention on it (art. 285 para. 4 and 5).

A single-family house with a ground floor, or a ground floor and one upper floor, is in consequence class CC1, and its project does not have to be checked by a certified project checker (Annex 6 and art. 440 para. 3). For extensions and extra storeys the class may, however, be changed with reasons (art. 370 para. 17), and a mansard added above an upper floor is one more storey, which the CC1 row no longer names. In that case, ask the designer which class the house falls into.

The steps, in order

1. Ask for the urban planning certificate for construction and learn the zone’s rules and the approvals required (art. 249). 2. Order the technical expertise of the house and, where relevant, the energy audit. 3. The designer makes the measured survey and the permit project, based on the expert’s conclusions. 4. Obtain the approvals and file the permit application. 5. Receive the permit and have it noted in the land book before works start (art. 314 para. 7). 6. A firm carries out the work, to the project. 7. Notify the end of works and hold the reception, with a town hall representative (art. 280).

After the works

The reception is mandatory for interventions too, and without it the work is not considered finished (art. 280 para. 1 and 8). The house’s entry in the land book also has to be updated. The Code does not say which documents the land registry office (OCPI) wants for an extended house, so ask OCPI or a cadastral surveyor before the reception; the steps for a new house are in our guide to registering a new house.

On tax, one trap: the Fiscal Code rule requiring a declaration within 30 days of an extension now applies only to non-residential buildings (art. 461 para. 6 of the Fiscal Code). For your house, ask the local tax office how and when to declare the new area.

If you have already extended without a permit

For work done without a permit you apply for a regularisation permit (art. 301 para. 1). It is available for single-family houses with a ground floor, or a ground floor and one upper floor, with a total built floor area of at most 150 m², outside protected zones; for other buildings only until 25 August 2027, at 10 times the fees. The law does not say clearly whether the limit refers to the whole house or only to the new part. You need a technical expertise for each quality requirement, and the work must also meet the planning rules and environmental law. If it does not, demolition follows or, depending on the case, a partial-demolition permit or compliance works (art. 301).

The fine for building without a permit is 50,000–1,000,000 lei (art. 357 para. 4). If you exceed the height regime in the permit, 50,000–500,000 lei is added for each unauthorised storey (art. 357 para. 5). The building tax rises by 100% from the moment the breach is found until regularisation or demolition (art. 301 para. 11). Details are in our guide to building without a permit.

Frequently asked questions

Short answers to what people ask most often about extending a house.

Can I build a small extension on a notification only?

Only a bathroom or a technical room of at most 25 m², outside protected zones. A living room, however small, needs a building permit.

Do I need an expertise for a light SIP storey?

Yes. A technical expertise is mandatory for any intervention project on an existing building, whatever the material. Low weight helps the old house, but how much it can take is the expert’s call.

Can I build the extension myself?

No. For existing buildings, the law allows self-build only for maintenance and routine repairs; an extension or a new storey is built by a firm, to the project.

Do I need my neighbours’ consent?

Under the planning code, only if the expertise calls for safety measures on their buildings. Under the Civil Code, if you want to build less than 60 cm from the boundary or open a window towards the neighbour less than 2 m away, you need their consent by notarised act.

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