Hørsholm: Denmark's most climate friendly kindergarten

Active House is a web-based platform for sharing knowledge about sustainable building. The vision is to set up a holistic framework for how architects of the future can design and renovate buildings in order to make a positive contribution to human health and well-being by focusing on in indoor and outdoor environments as well as sustainable energy. By bringing daylight and fresh air into focus, Active House wants to promote a better environment in cultural, architectural and environmental terms.

According to Active House, the buildings of the future must be opened up to exploit daylight and passive heat. Doing so will make for a healthier indoor climate for the people who live in or spend their days in the buildings. And without impacting on the climate, either. Active House's principles can be applied to new buildings as well as renovated homes, offices or public buildings. The object is to encourage architects and contractors to think sustainability into their building design, thus helping to strengthen cooperation on energy-friendly solutions in building projects, product development and research activities.
 
The climate-friendly kindergarten Solhuset (the sun house) is currently under construction in Hørsholm Municipality, north of Copenhagen. The building was designed, and is being built, according to CCO Architects’ interpretation of Active House's vision of giving more than it takes. Daylight plays a major role in the building. Partly because of the atmosphere it creates in the various rooms, and partly because of the passive lighting and heating of the rooms. The roof of the building is the core of its energy design, with solar panels positioned for optimum sunlight exposure both summer and winter. The building itself is constructed with few simple but larger structures in the form of concrete floors and walls. The concrete provides a larger thermal mass, able to store large amounts of passive heat from solar heaters on the roof.

By means of a weather station on the roof and sensors in all the rooms, the building's intelligent control system closes blinds to keep out the heat, ventilators with fresh air and shuts out the light so that energy consumption and the flow of daylight and fresh air for adjusted to comply with demands and the weather. The windows’ built-in blinds close at night, prevent overheating during the day and insulate against the cold at night. This makes for a stable indoor temperature, reducing the need for heating as well as preventing overheating during the summer. When the solar heating system, passive heating, optimum daylight conditions, solar collectors, solar cells and heat pumps are included in the equation, the building is self-sufficient in energy for heating, electricity, ventilation and lighting. Solhuset will thus be Denmark's first kindergarten to produce more energy than it consumes.

It has been calculated that over a period of 40 years, the kindergarten will “repay” the CO2 the building's materials and construction have "cost" the climate.

Energy production in Solhuset

Strategically positioned on the south facing roof surface, 50 m² of solar collectors will harvest energy directly from the sun, while 250 m² of solar cells will convert solar energy into electricity. The institution will produce 8 kwh per square metre per year, which exceeds its calculated consumption. The surplus energy production means that in about 40 years, the kindergarten will have repaid the carbon emitted in connection with the development of the primary building materials. Solhuset is thus expected to be carbon neutral throughout its lifetime.

Evaluation of Active House

Active House buildings are evaluated by examining the relationship between energy consumption, healthy indoor climate and impact on the environment. Quantitative and qualitative measurements are made of energy consumption, heat, hot water and electricity consumption.

The families living in eight demonstration homes are interviewed on a regular basis. Among the questions they are asked is whether they enjoy living in the houses. Active House currently has a PhD student drawing up a method of evaluating the holistic approach in accordance with which the active houses are built.