At the 6th International Conference on Energy Efficiency in Historic Buildings (EEHB 2026), Guna Bebre from Riga Technical University presented a poster on improving energy performance and indoor environmental quality in a reconstructed historic municipal office building in Riga.
The poster examined an eight-storey building within the Riga City Hall complex, located in the UNESCO Historic Centre of Riga. Using energy data, HVAC audit findings, indoor environmental quality monitoring and calibrated modelling, the researchers assessed the building’s current performance and developed a heritage-compatible retrofit package.
The proposed measures combine improvements to the building envelope with HVAC optimisation and solar-control glazing. The calculations indicate that these measures could reduce total final energy use by around 35%, improve the building’s energy class from D to upper C, and lower annual CO₂ emissions by approximately 75 to 80 tonnes. They could also significantly improve indoor comfort, with comfortable temperatures expected during more than 90% of the time the building is occupied.
A key conclusion is that optimising building services can generate considerable energy savings without altering the building’s protected appearance. The research also highlights the importance of combining on-site measurements with modelling to identify operational issues that standard calculations may overlook.
As a next step, the researchers plan to monitor the building after renovation to verify the predicted energy savings and improvements in indoor environmental quality. Further work will include an hourly assessment of overheating at the south-facing façade, the exploration of heritage-compatible solar-shading solutions, and a cost-benefit analysis of the proposed measures.
The full article will be published in the EEHB 2026 conference proceedings. Read the full poster here.
