From culturally significant to climate significance
Through new technologies for a more climate-friendly construction, energy use can be more efficient – resulting in reduced environmental impact and lower energy costs. The municipality of Oslo leads the way with a comprehensive renovation and expansion of the culturally significant Ullerntunet helsehus – the first BREEAM certified retirement home in the country.
In Scandinavia, the construction and real estate sector has long been one of society's major climate challenges. Through a building's entire life cycle, the production of building materials, long transports and heating of premises will contribute to a large share of the overall climate impact. To keep up with an increased general awareness of the climate issues, the requirements to build long-term and energy-efficient have amplified.
As the world has moved towards a greater energy consciousness, the demands on the real estate industry to act sustainably have gradually tightened in Norway. The public sector has been the pioneer in development over the past decade. When Oslo municipality was to renovate and expand the Ullerntunet retirement home in 2007, the ambitions were high - it would be Norway's most energy-efficient and environmentally-friendly care providing institution.
It is challenging to increase the energy efficiency of old buildings
ÅF acted as the design and build advisor in the project, and ÅF in Norway was responsible for the architectural planning. In collaboration with the Veidekke construction company, the main Ullerntunet building from 1923 was given a complete renovation and two new wings were constructed. Once the new Ullerntunet was ready in the beginning of 2017, it was Norway’s first BREEAM certified retirement home. BREEAM is an international environmental certification that guarantees that the building has been constructed with as low environmental impact as possible. It is the world’s oldest, and Europe’s leading, environmental certification for buildings. BREEAM certification assesses environmental performance of a building in nine categories – project management, energy consumption, health and indoor environment, transport, water use, materials, waste handling, land use, impact on local environments and contamination.
In line with the BREEAM certification requirements, a number of measures were taken to ensure a high environmental standard in both existing and new premises at Ullerntunet. Above all, these were measures to reduce energy consumption – no simple task as no major interventions were allowed on the main building from 1923 that was listed by the government as a cultural heritage.
“The new expansions have been built to the passive housing standard NS3701, a building technique where an energy efficient house is built by minimising energy losses. This means for example that the basic insulation in the property is better than in other buildings, which reduces heat loss. However, as the main building had certain protection requirements it meant we couldn’t insulate that part in the same way. In order to reduce energy consumption, we’ve put supplementary insulation below the roof and inside the walls, and replaced the old doors and windows with new ones which emit less heat. A completely new ventilation system has also been installed, which shares the heating system with the new buildings”, says Katja Tretiakova, BREEAM expert at ÅF, who has been involved in the project.
The passive housing technology is based on the fact that the energy generated in the house is recycled and distributed evenly in the building. The new building at Ullerntunet has a heat pump system that in combination with the boiler provides heat for room heating, ventilation and tap water. The ventilation system is commonly one of the most energy-demanding part of a building, and has great potential for saving energy. Air supply in care homes is particularly important since there is a significant risk of spreading infections if the ventilation is not good enough.
In addition to making the buildings more energy efficient, Ullerntunet has also been equipped with solutions that will stimulate a more sustainable lifestyle. “There is now parking for bicycles and electric cars, and inside the home there are screens providing information regarding public transport in real time. The idea is to encourage the visitors to leave their car at home and instead choose a more climate-friendly means of transportation”, says Asgeir Jørgensen, architect at ÅF Norway who led the development of the project.