The City of Lahti brings energy efficiency to renovation – check out the new videos

News 2022-08-04 at 13:17
© Lahden Talot

The City of Lahti is looking for low-carbon solutions for planning renovation projects for residential blocks of flats and terraced houses. In the houses of Lahden Talot, concrete climate measures are also implemented as part of the renovation of buildings. The work is being done as part of the ‘Towards Carbon Neutral Municipalities and Regions’ (Canemure) project.

The renovation sites of Lahden Talot are surveyed to see how the energy consumption and climate emissions of the existing residential buildings can be reduced in a cost-effective manner. The project monitors ten houses where various renovation and retrofitting activities are carried out and energy advice is offered to residents.

“Detailed measurement data is available on the energy consumption of Lahden Talot properties. The impact of each individual measure will be measured and, at the end of the year-long monitoring period, it will be known how the estimated energy savings will actually be realised. This way, we will be able to reliably calculate the impact of the measures on carbon dioxide emissions,” says Environment Coordinator Jenni Rahkonen from the City of Lahti.

The selected properties are surveyed for the possibilities of, among other things, the reduction of water consumption, waste heat recovery of wastewater, the use of renewable energy and the impact of improved energy advice on energy consumption.

Energy lessons from renovation

The City of Lahti also serves as an example to others. “We want to produce information that will support the renovation of other housing companies and residential properties. Using concrete examples, we show that renovation can be both economically viable and at the same time reduce climate emissions. The real estate portfolio of Lahden Talot is very similar to that of the rest of the country, which makes it easier to generalise the collected data throughout Finland,” Rahkonen points out.

The City of Lahti has created four videos on energy solutions for construction in order to disseminate good practices. The videos cover heating control solutions, water control solutions, heat pumps and wastewater heat recovery. The videos provide a brief description of the technical implementation of the systems and their impact on energy consumption.

Watch the videos

Heating Control Solutions (YouTube) (in Finnish)

Heating makes up about 65 per cent of the energy needs of housing and is one of the biggest costs of housing companies. The heating control system monitors living conditions in real time. It can be used to even out housing conditions and save energy. The heating control system was replaced at the site in Lahti. The investment was quick to carry out and proved to be inexpensive.

Water saving solutions (YouTube) (in Finnish)

The heating of water consumes about 17 per cent of the energy needs of housing. The production of domestic water consumes a lot of energy. The water consumption of the residential building can be significantly reduced by maintaining and replacing the plumbing fixtures. The building's water system was analysed and the plumbing fixtures were replaced at the site in Lahti. The cost of the measures was quickly recouped in savings in water and heating bills.

Heat pumps (YouTube) (in Finnish)

The heating of residential buildings and water makes up over 80 per cent of the energy needs of residential buildings. With the help of heat pumps, the heating of spaces and water can utilise heat energy from the sun stored in the ground and in the air, as well as waste heat from exhaust air or wastewater. An air-water heat pump system was installed in the site in Lahti in addition to the housing company's oil heating.

Wastewater heat recovery (YouTube) (in Finnish)

The heating of water consumes about 17 per cent of the energy needs of housing. Most of this energy ends up in the sewage system with the wastewater. The heat recovery of wastewater can be carried out with a heat exchanger designed for this purpose and connected to the sewer line of the building. A heat exchanger was installed in the site in Lahti.

Learn more

Further information

  • environmental coordinator Jenni Rahkonen, City of Lahti,, tel. +358 (0)44 482 6646

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