Are PassivHaus' The Way Forward To Zero Carbon?

Passive houses are a German design but can have a British location with a tropical climate, how is this possible? Because PassivHaus' are super efficient and their construction makes for warmer homes which translates into lower energy bills for the homeowner. Sounds too good to be true doesn't it. So if a PassivHaus offers this why aren't all new builds built this way?

Passive houses, as they are known in the UK, were designed in Germany in the 1990's by the PassivHaus Institute. Since then more than 30,000 homes, schools and offices have been built to their standard, although most of the builds have been in Germany and Austria. One of the first certified PassivHaus' in the UK was a three bedroom house in Denby Dale, Yorkshire and was completed in May 2010. The owner of the house says that it is as easy to run as any house as the technology is in the building of it. The PassivHaus is ideal for new builds as the high levels of energy efficiency are embedded into the house when it is being built. The end product is a house which uses 90% less energy than a standard house. The owners admit that the only big difference between their house and a normal one is the bills.

The first gas bill that the couple had for the house was just £26 for the quarter and the electric bill was even lower at £17. Compare these bills to the couple's last ones when they lived in a 300 year old terraced house where their bills were £1,800 a year and you can really notice the difference, as the owner said the difference was "phenomenal".

So what sets a Passive House apart from a typical eco-house which is becoming popular now? A PassiveHouse has no obvious green giveaways as it is the invisible components of the house that make it green. A PassivHaus works like a tea cosy, wrapping the house in continuous insulation rather than just the loft and walls. The company also insists on stringent levels of air tightness to create minimal thermal bridging or "the tea cosy effect". Like other eco houses a PassivHaus is designed to optimise the heat generated from the sun and they also have a MVHR system installed. This system provides the house with fresh air and helps to warm it by recovering heat from the extracted air and transferring it to the incoming air. Heat from inside the house, generated from humans or cooking etc. . is then retained within the building. Therefore this means that the house needs very little heating or air conditioning.

The owner of the house said that when the house was being built he visited it at night, it was -14C in the garden but the house was 10C. The Denby Dale PassivHaus is a pioneering project as there was, at the time, nothing similar in the UK. They visited ones in Austria instead and found them modern and light. It is possible to import them from Germany but builders over here are not familiar with erecting them and planning can be an issue. So the house was built locally with the stone from the builder's yard up the road and this house has cavity walls so it is like a traditional British house but with a Passive twist. The budget was £141,000, which proves those eco houses are not just for the wealthy. They have been tried and tested for twenty years and have proven methodology in achieving low energy buildings.

So What Is a Passivhaus Exactly?

Passivhaus is a term we are all likely to hear more often as we become ever more focused on energy efficiency. As you might have guessed from the spelling Passivehaus has its origins in Germany being part of the countries building standards. Any house meeting the standard will have been built to take advantage of the sun's heat and any other freely available source - including people, household appliances and regular fresh-air. One of the main factors which help to reduce the need for traditional heating is super high degrees of insulation as well as air tight windows and doors. The entire fabric of the house, including floors and walls, work by storing heat to help maintain warmth in winter. The addition of Solar panels and heat pumps may also play a part in supplying efficient forms of heat.

The main aim of a Passive House is to have low impact on the environment and as such will usually require around 75% less heating than a regular home. Although build costs can be up to 8% greater than a normal build the big benefit is obviously the savings the homeowner can make on fuel bills. On top of this the owner can also be fairly smug about their carbon output.

Air quality is usually controlled through mechanical means and heat recovery systems. For anyone who loves to be warm this is undeniably the house for you as temperatures are maintained at a constant level. Dust and pollen particles are filtered out of the air which is an added bonus to anyone who suffers from related allergies.

Adhering to the standards can be tough. Anyone keen on building a Passive House will need to consider the design and layout from the beginning. Planning permission will need to allow for large south facing windows and ventilation etc, so the right plot of land is essential. Consideration should also be given to internal lighting, appliances and any other energy demanding equipment you intend using in the house. When choosing an architect look for someone who understands the Passivhaus Planning Package (PHPP). This will enable the architect to gauge energy performance at the design phase. Ultimately you will need to have the house certified by the Passivhaus Institute, the BRE or the Scottish Passive House Centre so getting the design right is essential.

There's a lot to go though before you sell up and call in the removals company. Ignoring extra build costs, the Passive House philosophy has to be the logical position for all new home builders to aspire. Once you've considered the long term benefits, especially in such a windblown island as the UK, to build anything less is to build a house which effectively leaks heat. The Passive House is almost the exact opposite to a heating leaking house. By concentrating on minimising heat loss the need to constantly pump more heat into the house is virtually eliminated. Granted, all those tight fitting doors and windows and super efficient insulation don't come cheap, but it's exciting to think that technology can now deliver a much smarter home as well a more comfortable one.