Extreme Heat Exposes Flaws in the Design of Residential Buildings Across Bulgaria

A large proportion of residential buildings in Bulgaria were not designed to provide adequate protection against record-high summer temperatures. The problem is most severe in ageing prefabricated apartment blocks, where millions of Bulgarians remain trapped by the heat, even inside their own homes.

High-rise developments, residential buildings constructed too closely together, and the widespread enclosure of balconies with glazing are among the planning mistakes that restrict natural airflow and trap heat. These shortcomings are acknowledged by Professor Krasimir Enimanev, a structural engineer who took part in the construction of two of the largest housing estates in the city of Ruse during the 1980s.

Prof. Krasimir Enimanev, structural engineer:
"Tall and low-rise buildings are not alternated. Architects broke the rules due to various directives that favoured financial interests. Some of the high-rise buildings that were approved block the movement of air. The worst decision is glazing balconies. It creates an aquarium effect."

Conditions are particularly difficult for residents living on the top floors, where overnight temperatures do not fall below 30°C and air conditioning is the only relief during heatwaves.

To cool his flat even slightly, Todor Gerov pays almost €200 in electricity bills during the summer months.

Todor Gerov:
"My flat faces south, so it's like a greenhouse. In the morning we try not to switch it on, but in the afternoon there's no alternative – it becomes unbearable."

Residents of modern buildings with glass façades also say they do not feel comfortable inside their homes, as many of the buildings lack air-conditioning systems.

Prof. Krasimir Enimanev, structural engineer:

"Between the façade and the building itself, air circulates, which allows the entire building to be cooled. There are still no properly constructed examples of this in Ruse."

The lack of green spaces, combined with extensive concrete and glass surfaces, has turned many of Bulgaria's larger cities into urban heat islands. In response to climate change, the Municipality of Ruse has begun introducing cooling systems that spray fine water mist in busy public areas across the city.