Case Study: Retrofitting of multi-apartment building Sütiste tee 45

Short Description

The renovation was started in 2000 with the basic refurbishment measures. The aim was to achieve energy saving and retrofit the building. The complex renovation was financed by apartment owners and bank loan and carried out in 2002- 2007.

Key Elements

Certification

An energy audit has been carried out for the building.

Work with Residents

An individual heat allocation system was introduced to the residents to help them to save energy in everyday life.

Funding

The renovation was started in 2000 with the basic refurbishment measures. These were financed by apartment owners who founded an association in 1999. Complex renovation started in 2003 with the support of a bank loan. Today the apartment association has invested more than 7.2 million EEK (more than €460 000), this includes the loan 5.5 million EEK (€351,000).

Thermal Insulation

The gable roof was renovated and insulated, covered with profile metal, insulation wool under roof (thickness 30-40 cm) on the top of the concrete panels. Sidewalls and facades were insulated with polystyrene blocks (EPS 100 mm). Balconies were insulated with polystyrene blocks EPS 50 mm. Technology: polystyrene blocks were fixed with glue and stabilizers covered with net and decorated with coloured parget.

Windows and Shading

New windows for apartments were installed, previous wood windows were replaced with plastic packet-windows with two glass panes. Balconies were glazed with sash windows.

Ventilation

The ventilation system was renovated during the windows replacement. There are ventilation- grids above the new windows now.

Heating and Hot Water

The heating system was renovated, with a modern district heating substation being established. A one-pipe heating system was replaced with a two-pipe system. Hot and cold water pipes were replaced with new ones. An individual heat allocation system was introduced. Radiators were replaced and thermostatic valves were installed on all radiators.

Electricity Saving Products

All electricity system was renovated.

Main Results

• A 50% energy saving was achieved. In 2001, the heat consumption was 187 kWh/m2 (845 MWh) and in 2007 it was 94 kWh/m2 (437 MWh) (all consumption data have been corrected with degree days methodology). CO2 emission calculations for the building were 283 tonnes per year before investment and 153 tons per year after investment. Total savings for CO2 are 130 tonnes.
• The outlook of the building has been improved: colourful walls, sash windows, a new roof and new storm porches give a good external appearance to the building.

Lessons learned

• Energy saving may be achieved with basic energy efficiency measures.
• External wall insulation should be made in conjunction with heating system renovation to avoid overheating after renovation (a weak point in the project was that the heating system was renovated before insulation and the overheating started after renovation because there was not need for so many radiators anymore).
• A strong point in the project was the introduction of the individual heating accounting system which gave the users a real motivation to use thermostatic valves and consume less energy (as well as invest more to get the system).
• In a multi-apartment building much effort must be made at the beginning of the refurbishment process to raise the awareness of apartment owners and thus help to prevent conflicts in the future (a weak point in the project was that some apartment owners did not understand the aims of the project in the start and it needed extra effort from the board of the apartment association to persuade them to continue with the project later).