Stay ahead of the game

Whatever happens to the price of energy, the UK has the leakiest homes in Europe, and energy efficiency is one of homeowners’ most important concerns: they expect their windows to be increasingly energy efficient. Swisspacer talks to Glass Times.

The glazing industry is moving on from A to A+ and A++ rated windows, and now Passivhaus. At every stage of this journey, warm edge spacer bars play a crucial role. Over 30,000 projects have been certified Passivhaus worldwide, with many featuring Swisspacer inside the sealed units for optimum thermal efficiency.

Karl-Theo Roes, Swisspacer’s head of market development in Europe, and Dr Benjamin Krick of the Passivhaus Institute, explain and review the many benefits of Passivhaus.

What does the Passivhaus idea mean and what are its aims?

Karl-Theo Roes: The first thing you notice with a Passivhaus building is there are no heating elements. Yet it is still nice and warm in winter, as the ceilings, walls, roof and windows are extremely well insulated and the building shell is really airtight, so very little heat can escape.

As a preference, the electricity required is created through renewable energy, such as photovoltaic energy, and the hot water is produced through solar thermal energy or heat pumps. The Passivhaus concept saves energy and plays an important role in tackling climate change.

Dr. Benjamin Krick: Passivhaus stands for maximum thermal comfort with minimal energy use, reducing energy needs to such an extent that consumption can be covered by energy generated in a sustainable manner. The energy costs are lowered and the slightly increased costs of constructing a Passivhaus building are quickly compensated. There will even be a little profit left over.

In what direction is the building sector moving in terms of energy efficiency?

Karl-Theo Roes: The construction industry follows the energy guidelines laid out by the politicians, but at the same time, the industry needs to offer economically viable solutions.

The 2020 EU Energy Efficiency Directive calls for “nearly zero-energy buildings” in the next few years. Several home builders are looking for components with maximum energy efficiency even now. We too are seeing that when it comes to windows. In Germany, the energy-saving regulation uses the UW reference value of 1.3W/m²K for windows, but customers are predominantly buying windows with UW values of less than 1.0W/m²K.

Dr. Benjamin Krick: With rising energy prices and a growing awareness of climate change, the requirements in terms of energy efficiency are increasing. Triple glazing is proving useful even in some regions in Spain and Portugal. For one thing because of its improved insulation, but also because it protects against the sun’s rays in summer a little better than double glazing.

Is today’s market ready to accept the conditions that come with the Passivhaus concept?

Karl-Theo Roes: The Passivhaus idea was and is revolutionary and has already had a considerable impact on the market for some 20 years. This is reflected by how the insulation in the building shell has been developed. The construction industry has already implemented a few ideas, with a number of Passivhaus windows and facades on the market, for example.

Dr. Benjamin Krick: The market is continuously developing. Supply and demand influence one another. New products are supplied to satisfy a certain level of demand. When a product is first brought to market and advertised, demand will rise. Certified Passivhaus components play a key role here by ensuring that the demand for these and similar products grows.

This paves the way for new products into the market. In this way, highly energy-efficient products move from niche to mainstream. In Germany and Austria, triple glazing, for example, has a market share of over 60%.

What does Swisspacer do? What products do you offer and what connection do you have to Passivhaus?

Karl-Theo Roes: The edge of the insulating glass is a critical weak point in the building and a lot of energy can escape through it. Swisspacer provides high-quality warm edge spacer bars, which reduce the thermal bridges at the edge of the insulating glass and significantly decrease the amount of energy lost. This saves money – when heating in winter and cooling in summer. In addition, with Swisspacer spacer bars, you can reach far higher temperatures at the edge of the glass, fending off the risk of mould or condensation.

Swisspacer boasts the first spacer bar that was certified by the Passivhaus Institute. Plenty of certified Passivhaus windows only satisfy the strict criteria because they contain Swisspacer spacer bars.

How does Swisspacer tackle energy efficiency?

Karl-Theo Roes: Our clients are insulating glass manufacturers and they expect products with the best energy efficiency from us. However, we also work very closely with architects, window and facade manufacturers, as well as energy consultants and building biologists. We listen to all those involved, learn from them and then develop new products and solutions.

In the meantime, word has spread that our small component has a big impact on the building’s energy-related characteristics and contributes to the living comfort. It looks good too.

The subject of energy efficient windows and facades is the focus of the European fenestra-vision symposium, which Swisspacer organises every two years, and will be on 15 September in Salzburg, Austria this year. Over 100 international, high-level experts from the fields of science, teaching, research and industry come together to exchange ideas about the future of windows and facades. Through the symposium, we want to help ideas and visions turn into practical and innovative solutions.

How can the Passivhaus message be brought to society as a whole and have it accepted by them and not just by technical experts?

Dr. Benjamin Krick: The Passivhaus Institute’s component certification plays a key role here. For example, if a company has a certified product, it will advertise both that product and Passivhaus, and thus it will be advertising maximum energy efficiency. That is how to raise awareness of the subject for many customers.

Ultimately, however, the best way to convince people is through their own experiences. That is the aim of the Passivhaus Conferences run by the International Passive House Association (IHPA). This year, they are taking place in primarily warm climates on June 24-26  to show that Passivhaus buildings are pleasantly cool in summer too. In cold climates, Passivhaus units will open their doors from November 10 to 12  to demonstrate the cosy warmth inside Passivhaus buildings. Further information is available on the IHPA website:

Are there ongoing Passivhaus projects involving Swisspacer?

Karl-Theo Roes: Swisspacer spacer bars are used in the majority of all Passivhaus windows and facades. There are currently around 210 certified Passivhaus windows, fixed glazing units and sliding doors and Swisspacer is used in 75% of them. Of the 31 facades that have been Passivhaus certified to date, 30 use Swisspacer – almost 100%.

Swisspacer is used in Passivhaus single family homes, and in Passivhaus office buildings, nurseries and schools. For example, the Hebei Academy in the Hebei province in China was finished last year, making it the first public Passivhaus building there. The large research laboratory is a shining example of energy-saving building technology like the Swisspacer spacer bar.

Swisspacer G40