Most renovation work inside a flat needs no paperwork from the municipality. There is, however, a clear line beyond which the work becomes "construction" in the legal sense, and without a permit it is unlawful. Here is where that line runs and what else you have to respect when you live in an apartment block.
Under Art. 151(1)(1) of the Spatial Development Act (ЗУТ), no building permit is required for routine repair (текущ ремонт) of buildings and installations. The Act defines routine repair (§ 5, item 43 of its Additional Provisions) as improving and maintaining the building in good order, including internal alterations that:
In practice this covers painting and plastering, new flooring and tiles, new sanitary ware, electrical and plumbing work inside the flat, new windows and doors, a new kitchen and built-in furniture, and moving light (non-load-bearing) partition walls.
Art. 151(1)(6) also expressly exempts glazing in balconies and loggias from the permit requirement. For listed cultural heritage buildings and their protection zones, even this work must be cleared under the Cultural Heritage Act (Art. 151(2)).
As soon as the work affects the structure (a load-bearing wall, column, beam or floor slab) it is no longer routine repair. It becomes an alteration, a major repair (§ 5, item 42) or a reconstruction (§ 5, item 44), and the general rule applies: construction may only be carried out if permitted (Art. 148(1)), with the permit issued by the municipality's chief architect (Art. 148(2)).
Typical examples:
Work done without a permit is unlawful construction (Art. 225(2)(2)) and can be stopped and ordered removed. It also causes trouble when you sell. Banks and notaries look at the documents, and a gap between the approved drawings and what is actually there becomes a point of dispute.
Whether a wall is load-bearing cannot be judged by eye. It depends on the building's structural system. Before anyone picks up a hammer, get a site visit and a written opinion from a fully licensed structural engineer. If they confirm that the wall is not load-bearing and the loads do not change, the work stays routine repair. If not, they will prepare the structural part of the design needed for the permit.
For a change of use (office, practice, shop), Art. 38(7) expressly requires a reasoned structural engineer's opinion. See our guide to change of use.
Load-bearing walls, floor slabs, columns, external walls, the roof and the main lines of the installations are common parts of the building (Art. 38 of the Property Act). Any alteration that touches them therefore needs the neighbours' consent as well as a permit:
Even routine repair is subject to ЗУЕС. An owner must not damage other units or the common parts, and must not impair the architectural appearance, load-bearing capacity or fire safety of the building (Art. 6(1), items 2 and 5). This applies to balcony glazing and window replacement too: neither needs a permit, but neither should change the façade arbitrarily. It is good practice to tell the building manager and your neighbours in advance.
In Sofia, the City Council ordinance on public events, municipal property and noise in residential buildings bans noise from construction and repair work on working days between 22:00 and 08:00 and between 14:00 and 16:00 (Art. 19(1)). On weekends and public holidays noisy work is banned altogether unless the affected residents agree (Art. 19(2)).
The fine for an individual is €51 to €102, and the penalty for a company is €102 to €204 (Art. 29(1)). Other municipalities have their own ordinances, so check yours.
According to Sofia Municipality:
If the skip has to stand on a pavement or street, check with the district administration beforehand whether a permit is needed and on what terms.
A leak into the flat below is the most common renovation dispute. Under ЗУЕС, an owner must compensate damage caused to other units while fixing faults in their own (Art. 6(1)(14)). After an alteration under Art. 185 ЗУТ, the owner must repair all damage caused by the works (Art. 185(6)). Check whether your home policy covers third-party liability and what cover your contractor carries. There is more in our guide to home insurance.
Sign a written contract with the contractor covering scope, timeline, price and warranty, and keep the invoices and handover records. The Ministry of Finance has proposed that payments in construction be made only by bank transfer from 2027. For now this is a draft, not a rule in force; details are in our news piece.
This article is general information, not legal or technical advice for a specific case. Verified October 2026.
If you are planning a renovation before selling, or buying a flat that has already been altered, call us or visit our office. We will go through the documents with you and tell you what to check.
