24 June 2010

Denmark's first Passive+ house inaugurated by Energy & Climate Minister Lykke Friis

There is a substantial green job potential in energy-efficient buildings. The first Passive+ house in Denmark, inaugurated by Lykke Friis, the Danish Minister for Climate and Energy, is paving the way for new construction. The house produces more energy than it consumes.

The Danish Minister for Climate and Energy, Lykke Friis, inaugurated Denmarks first Passive+house (photo: Steen Brogaard).

Zero energy bills – or even a positive balance on the account. It sounds almost too good to be true, but this will the reality for Kalle Christensen and his family. The Danish Minister for Climate and Energy, Lykke Friis, inaugurated Denmark's first Passive+ house on 24 June. The green leap forward was taken in Northern Europe’s largest low-energy area, Stenløse South. Lykke Friis says:

"Buildings are responsible for a substantial proportion of our CO2 emissions. Since COP15, our task has been to demonstrate via practical solutions that green transformation is possible, and that reducing our consumption and becoming independent of fossil fuels goes hand in hand with competitiveness and green jobs. The Passive+ house is not just a good initiative on Danish soil: the project's prospects are far-reaching in terms of job creation, exports, the climate and the consumer. A real house containing real people: that's what we need."

Housing designed to meet future EU requirements

Within the Rockwool Group, which has contributed to the construction of the house, this product is viewed as an important step towards green exports of the future.

"France already has plans to introduce energy plus housing standards," says Eelco van Heel, CEO of Rockwool International. "Germany and Great Britain are also about to introduce energy requirements for new buildings that will put Denmark on the back foot. And the EU has just agreed on requirements for near-zero energy buildings before the end of 2020. If we want to succeed on the international clean tech market, it is vital for construction firms to take a visionary approach and acquire in-depth experience of building energy-efficient buildings. These are solutions that we can export, and which can secure important green jobs in the future."

Stenløse low-energy – international renown

It is no coincidence that this ground-breaking house has been built in Stenløse. This is the building site of what is arguably Northern Europe's largest low-energy development, and it has already attracted international attention. In the past year, several hundred journalists and political decision-makers from all over the world have visited the Egedal Municipality. They are eager to pick up know-how from the visionaries who are building popular housing that is equipped for future energy costs and climate challenges.

As Mayor Willy Eliasen says, "Here in Stenløse South, we have proved that it's possible to build better homes that save more than enough expensive energy to offset the little extra monthly mortgage costs. So why wait to introduce super low-energy requirements in future building regulations? When that happens, people in this area will automatically increase the energy efficiency of their homes by a further 25%. And other municipalities can easily follow our example. This is beneficial to domestic energy bills and to Denmark's clean-tech exports."

Behind the scenes

The man behind the Passive+ house is Finn Christensen from the construction company of Passivhus Design ApS, which has recently developed an innovative design model for passive house construction. Now he's taking it a step further and has built a fully-insulated passive house, which will be upgraded to a home with a positive energy balance just with a moderate a solar cell system.

"I see it as a challenge to build a house that will remain strong into the future from an energy point of view, and which also offers international potential. And that's what I think the Passive+ concept offers," says Finn Christensen, who is also working on projects in southern climates.

The Passive+ house in Stenløse has an area of 172 square metres and costs DKK 2.5 million. It is studded with insulation, and a new solar cell system will ensure an annual surplus of renewable energy, which will be sold to the power grid.

About Denmark's first Passive+ house at 17 Kærdalen, Stenløse

How the Passive+ house was built

The Passive+ house at 17 Kærdalen in Stenløse, 30 km from Copenhagen, was developed by Passivhus Design ApS, which is owned by Finn Christensen. The Rockwool Group is contributing to the project along with various other suppliers. The efficient insulation and super low-energy windows optimise the building envelope, and that's not even mentioning the efficient ventilation and heat pumps (air-to-water). The nucleus is a passive house certified in accordance with PHPP (Passive House Planning Package). A passive house is one that is so well insulated that the free (passive) surplus heat from devices, sunlight and body heat is the building's major source of heat. Solar cells are built into the roof, producing power for heating, light, electrical devices and hot water consumption.

Solar cells

The solar cell device from Racell is barely 46 m2 and not only reduces electricity and heating bills to zero: it actually produces surplus energy. In the winter, nearly 80% of the building's energy production is used for electricity and heating, but during the warmer months of the year, only around 20% of the energy produced by the solar cells is used. This means that the house produces more energy than it consumes, and the energy company transfers this power back to the grid. As Finn Christensen of Passivhus Design ApS explains:

"We planned the house so that it produces the maximum amount of green surplus energy that the energy company is willing to take back from a single-family dwelling annually. That's 6000 kWh. This produces an annual saving of 5.75 tonnes in CO2 emissions.

"In countries such as Germany and France, cheap loans or substantial financial subsidies are allocated to well-insulated super low-energy houses and energy+ dwellings. The situation is not yet like this in Denmark. And while our Danish energy companies pay the same for a kilowatt hour of solar power that we pay for a kilowatt hour produced from a pollutant carbon source, German solar panel owners receive three and a half times more money for the eco-friendly solar energy than is delivered to the supply network. If the goal is to make Denmark independent of fossil fuels, we will not achieve this unless we create greater incentives to build plus energy homes here."

Price, time and size

The family of two adults and their three-year-old daughter, Freja, have 172 square metres to rattle about in. Current calculations indicate that the price of the new house per square metre is 15,000 Danish kroner, i.e. an overall price of DKK 2.5 million + land.

Insulation

Roof and wall designs were built using 500 mm Rockwool Super FlexiBatts insulation, which has a high insulating capacity.

Windows

The windows are a new type of super low-energy product: the Svare model from Vrøgum. They are completely aluminium-free, and contain no external wood; instead, they feature 6 mm energy-efficient reinforced glass. To minimise wear and the need for maintenance, wood is only used internally. The skylights are produced by Velux.

Ventilation

The ventilation device is a Paul product, certified by the Passive House Institute in Darmstadt. The Stiebel-Eltron heat pump has an efficiency of 4.5. In other words, the home-owner obtains four and a half times more energy for heating than the kilowatt hours that are put into the device. Low-temperature floor heating is used for heating, and the equipment incorporates the Rehau geo-thermal tubes that pre-heat the supply air in winter and provide cooling in summer.

Building envelope without gaps and leaks

The new Passive+ house is very well-sealed with a single load-carrying structure which was specially developed by Passivhus Design Aps. There are rafters all the way round with sufficient space for the powerful insulation. Cables and pipes are installed internally so that the building envelope remains complete and unpunctuated, except for the openings that fit the windows and doors. This reduces heat loss and the risk of condensation and mould. To ensure the best possible exploitation of solar gain, the building faces south and the roof is angled at 43 degrees.

Certified in accordance with the newest PHPP standard

The building in Stenløse is the first Danish energy plus home to be certified as a passive house in accordance with PHPP (Passive House Planning Package). PHPP is a calculation tool developed by the internationally renowned Passiv Haus Institut in Germany. Consulting engineers Ellehauge & Kildemoes carried out sophisticated energy calculations and managed the certification process in accordance with the passive house standard. The actual certification is always undertaken by an independent body, which checks the energy calculations for the certification in order to ensure a high quality.

According to the international standards established by PHPP, the annual heat consumption of a passive house should be less than 15 kWh per square metre.

Our house

The low-energy area of Stenløse South, where the house has been built, is in Egedal, a municipality which requires all new construction to meet a minimum of low energy class 1. This is 25% better than the increased minimum requirements which are being introduced in Denmark later in 2010. The Passive+ house exceeds the authorities' requirements.

Kalle Christensen, the lucky owner of the Stenløse Passive+ house, says: "My wife, Anne, and I helped to decide what our home should look like, down to the smallest detail, both inside and outside. The most important thing for us was to build a home where we had better control of our heat consumption. That's why we initially chose to build a passive house.

"Together with Passivhus Design, we were able to take the final step and build a passive house that is actually a dwelling with a plus on its energy balance. One of our requirements, however, was that the house needed to fit in with the style of the neighbouring housing. It does, and it is to a great extent our own house, but adapted to all the requirements for passive house certification. We have been delighted to move in, and enjoy a comfortable indoor climate. And we're certainly happy to wave goodbye to electricity and heating bills."