Ambitious targets drive the City of Helsinki’s housing production

The City of Helsinki is constantly seeking new methods to improve energy efficiency in its housing production. What are some of these methods? What do new energy efficient city blocks look like?

Three new buildings for the Helsinki City-owned housing company, Heka, were recently granted Green Financing. The buildings’ E-values represent the best in the industry: for example, the annual efficiency of their heat recovery ventilation is extremely high, between 70% and 79%.

This is not unusual for Heka buildings, as energy efficiency is an important factor in all the company’s construction. As the largest lessor in Finland, Heka’s actions carry considerable weight. The company’s nearly 50,000 dwellings are home to more than 92,000 Helsinki residents. The company orders its new building and renovation projects from the City of Helsinki’s Housing Production Department, which manages the projects in full from design to implementation.

“The City of Helsinki aims to be carbon neutral by 2035. This is a tough goal, and we will have to employ all the measures possible to achieve this,” says Minna Launiainen, HVAC Design Manager at the City of Helsinki’s Housing Production Department.

The three new buildings with Green Financing will be built in the districts of Kulosaari, Myllypuro and Mellunmäki. The energy efficiency class of one of the buildings will be A and the others B.

“These new buildings will have efficient heat recovery ventilation, LED lights both inside and out, and solar panels. Our goal has long been to produce buildings with an energy efficiency class that is above the regulated level and with E-values below 80,” Launiainen says, describing the City’s energy saving measures.

The will is there but more solutions are needed

The City of Helsinki’s Housing Production Department is continuously seeking ways to also reduce the energy consumption of its existing buildings. The thermal insulation capacity of the buildings is improved in connection with façade renovations, the windows are replaced, and the ventilation is replaced with mechanical supply and exhaust ventilation and equipped with heat recovery. Some buildings are also fitted with exhaust air heat pumps, and the heat obtained from them is used in heating domestic water.

Renewable energy is utilised wherever possible.

“We have installed solar panels in some of the existing buildings. We have also investigated utilising geothermal heat, but have not yet succeeded in making it work for one reason or another. In some locations, for example, the reserve in the underground formula prevented the drilling of geothermal holes,” Launiainen explains.

A centralised and remotely controlled building automation system is installed in all new and renovation projects implemented by the City of Helsinki’s Housing Production Department. For example, the indoor temperature of the apartment in addition to the outside temperature is utilised in controlling the heating.

“We are already able to apply a wide range of automatic functions to optimise energy consumption. We will be able to do much more in the future. Adding smart functions is just a matter of programming.”

There is plenty of will to improve energy efficiency, but the solutions are not always easy to find.

“Sometimes the absence or complexity of ready-made solutions prevents the implementation of plans. We need equipment manufacturers to create ready-made concepts and solutions that would be easy to plan and implement even outside renovation projects,” Launiainen says.

Money can also present an obstacle to the most energy-efficient solution, especially if the cost of the renovation verges on that of a new building.

“It’s truly vexing if, for example, heat recovery, which is the most effective way of conserving heating energy, cannot be installed for economic reasons. It’s important to consider life-cycle costs, instead of just investment costs,” Launiainen emphasises.

In its housing production, the City of Helsinki examines life cycle costs more and more also when constructing new buildings.

“We have acquired a tool that allows us to calculate a project’s life cycle costs already at the start of project planning.”

From an expert point of view, what would be the best way to achieve the climate goals in the housing sector?

“There should be a lot more renewable energy in buildings! Of course, producing district heating in a renewable way would be the best solution.”

From individual houses to energy efficient city blocks

A new residential area will be built during the next decade on the north side of the district of Pasila where the former ground transport centre used to be. The area has an environmental theme and energy efficiency targets consistent with it. According to Launiainen, the new areas will be built in one city block at a time. The same block may include rental, right-of-occupancy and owner-occupied dwellings.

“All the buildings in the four city blocks currently being planned will belong to energy efficiency class A, and all will have the Finnish RTS environmental rating. In addition to solar panels, the buildings will include waste water heat recovery, which is a fairly effective way to save on heating costs.

According to Launiainen, it is not heating but water heating in modern, energy-efficient buildings that eats up a large proportion of energy and euros.

“We strive to reduce water consumption by using new technologies and equipment. Our new buildings have apartment-specific water meters, which seems to clearly reduce water consumption.”

Text: Hannele Borra
Photos: Lahdelma & Mahlamäki Architects