The heating bill is one of the most disputed costs in a Bulgarian apartment block. Neighbours with identical flats pay different amounts, and an owner whose radiators are off still gets an invoice. The reason nearly always lies in how the law splits the building's heat. Once you understand it, you know which parts of the bill you can influence and which you cannot.
In a condominium building connected to one substation, heat is allocated through a heat cost allocation system (Art. 139 of the Energy Act). Total consumption is split into hot water and space heating, and space heating into three parts (Art. 142(2)):
Only the third part depends directly on how you heat your home. The first two are shared among everyone under rules that have nothing to do with your own devices.
Readings and bills are handled by a heat cost allocation company. Choosing it is a decision for the general assembly of the condominium, which also appoints a representative to deal with the heat supplier and the allocation company.
During the season you usually pay monthly estimated amounts. Once a year the company reads the devices and prepares building and individual reconciliation statements, showing whether you owe a top-up or are due a refund. Deadlines for complaints and payment options are set in each heat supplier's general terms — check them and keep your statements.
How to make the most of your radiators is covered in our guide to saving energy without a major renovation.
The pipes in the building give off heat whether or not your radiator is on, so the law does not let an individual owner opt out of this part. The method for calculating it is chosen by a general assembly decision taken before the heating season starts (Art. 143(1)).
In its judgment of 23 October 2025 in case C-760/23, the EU Court of Justice confirmed that such a national rule is permissible — even where the stairwell has no radiators — provided the calculation rules ensure transparency and accuracy. In 2026 the Ministry of Energy published a draft amendment to the heat-supply ordinance setting a default method for buildings without an assembly decision and monthly disclosure of every input.
A single flat. You can switch your radiators off, for example with thermostatic valves. However:
Your bill goes down, but it does not go to zero.
The whole building. Opting out for all properties on one substation is possible by written application from owners holding at least two-thirds of the ownership, as set out in the supplier's general terms.
Widespread removal. If the total output of connected radiators falls by more than 50% of the design value and the installation gives off more heat than the flats use, the allocation company must notify the customers, who then decide whether to stay connected at reduced load. It is a warning sign that bills in the building will keep getting less fair.
Whether the stairwell is heated is decided by the general assembly. If there are radiators in the entrance, their consumption is shared among all customers — on top of the building-installation charge, which everyone pays even in a cold stairwell.
Replacing radiators or moving or renewing risers requires a design by a qualified professional and the heat supplier's agreement. Where common parts of the installation are affected, a condominium decision is also needed. Unapproved changes lead to penalties and disputes with neighbours.
Under EU energy-efficiency rules, meters and heat cost allocators that cannot be read remotely must be upgraded or replaced by 1 January 2027, unless this is not cost-efficient. Expect device replacements in many buildings — ask the allocation company who pays and when.
After completion, record the readings in the handover report — more in our guide to transferring utility accounts.
We go through a property's running costs with the buyer before any deposit is paid. If you are looking for a flat to buy and want to know what winter will really cost, call us or come into the office.
This is general information, not legal advice. The detailed rules depend on the heat supplier's general terms and the condominium's decisions. Verified as of October 2026.
