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These days the construction industry is increasingly geared towards providing sustainable housing that will meet stringent energy use standards. Homes known as ‘passive houses’ have been popular throughout continental Europe for some time and a passive house could be the ideal construction method for a new build in France. German company Hanse Haus, have been building pre-manufactured timber homes for over 80 years and are now considered one of the market leaders in the construction of passive houses.
So what is a passive house and why would one be right for you? A passive house is a house that achieves spectacularly high insulation levels. This means that any heating requirements are extremely low. As an example, a passive house requires around 15 kWh of energy per square meter whereas a property constructed in the 1960’s would need as much as 200 kWh per square meter. Apart from the obvious savings in running costs, the big advantage of passive homes is that they use energy efficiently. Each house is designed to suit the individual plot and sited to maximise solar gain. Large, south facing windows mean that natural solar radiation is used to heat the house. Inside the house itself, the heat that is produced from electrical appliances, lighting, cooking and even the occupants themselves, is not wasted. A central ventilation system with a heat recovery feature constantly changes the air in the living areas, recycling the warmth contained in the outgoing air into the incoming fresh air.
This means that heating energy would only be required on the very coldest of winter days. Hanse Haus homes provide this ‘top up’ heat with a ground source geothermal system and domestic hot water is provided in the main, by solar collectors. This type of heating system is very economical to run and could be an ideal solution for French property owners in areas where winter temperatures frequently drop below freezing.
Hanse Haus homes have several key features which contribute to their extremely low running costs. The innovative heating system which pre-heats incoming fresh air, firstly through underground ducts and then by recovering heat from the warm exhaust air, is one. The floor slab is insulated underneath with a massive 300 mm of insulation and below the screed lies another 120 mm of insulation. This means that almost no heat is lost into the ground and the U value is just 0.09 (W/meter squared K). All the windows are triple glazed and have special insulated frames which gives an extremely low U value of 0.61. Walls are highly insulated with an overall thickness of 410 mm; they are insulated externally and with a mineral wool filled insulated inner wall cavity. The roof is also insulated extensively with insulation between the rafters and in the services layer. Particular attention is paid to the airtight construction of the building, all of which is assembled in the factory before being shipped to the site for construction. This airtight construction means that heat cannot leak out through joints or gaps and thermal bridges, areas where heat could be lost, are kept to a minimum. Hanse Haus homes are all verified by the Passiv-haus-Institut in Germany to ensure that all the elements comply to passive specifications.
Clearly Hanse Haus buildings offer numerous technical advantages compared to a traditional construction method. They are also ideal for French home owners for many other reasons. The homes are suitable for all regions of France as they can be built in any style to match the local architecture. Modern, traditional and bespoke models are all available and each house is custom built to suit the owners individual requirements. The showroom carries roof tile samples that are used throughout the whole of Europe so meeting local planning requirements is no problem.
One of the biggest advantages is that the company offers a ‘one stop’ solution for the entire project. The main factory site contains six show homes where prospective customers can see the finished products as well as the manufacturing process from start to end. There is also a huge showroom displaying everything from drainpipes to carpets and shower units. This enables clients to order everything at the same time and means that after the building is made watertight, it will take no longer than six weeks to be completely finished. Customers can opt to take delivery of the building at the watertight stage - hors eau / hors air - but being able to leave everything down to the smallest detail is a great benefit for those who are not full time residents in France. All the delays that are usually associated with a building project are also avoided as everything, even down to items like handrails and balconies. is made in-house. In addition, as all the component parts are assembled in the factory, the building is delivered ready to be erected and can be put up in just two days. The panels are covered with a protective sheet so construction can take place even in the rain! The only possible delay could be caused by extremely high winds which might make operating the crane too dangerous.
Hanse haus homes all feature maximum levels of thermal insulation. This means that they have minimal heating costs and are thus more economical to run. This is a real benefit to home owners. For second home owners in France who plan to rent out their maison secondaire, knowing that running costs are low is an extra bonus. They can factor this into the rent and a property with low heating costs will always be attractive to clients looking for property to rent in the low season, whether short or long term. The other Hanse Haus buildings that are not designed to be built to passive standard, all offer very low energy consumption due to the construction methods. These homes can be fitted with an alternative heating system, such as a gas condensing boiler if required. The company can also design and implement a rainwater harvesting system which will be integrated into the house in the manufacturing stage.
The buildings have been designed to provide a very high level of comfort. Waste pipes are insulated to reduce noise and shutters can be automatically operated to react to sun and weather conditions. Households with noisy hobbies can even request additional levels of acoustic insulation. The floor cassettes are a solid mass of insulated timber. They are then counter battened to reduce noise levels. High performance OSB (Oriented Strand Boards) is added as a solid basis for the floor screed. They are then insulated and screeded. This provides a really solid floor as the UK and France sales agent Giles Hirst explained with a smile, ‘When the kids start jumping on their beds, it doesn’t sound as though they are going to come through the floor!’ Angled plasterboard is used around the windows; this gives a really crisp finish. The overall building standard is of extremely high quality and the finish levels are impressive.
The construction method means that there are no gaps in the building. This is important for heat loss but has the additional benefit of ensuring that rodents or other vermin cannot get in. Holiday home owners who have returned to find their property inhabited by M. et Mme Mouse and their numerous children, will appreciate this.
Delivery is simple too! The building arrives on site by trucks. These will be six or twelve meters long depending on site access and the house will have been built to the right size for the trucks in the factory. The cargo is accessed through zip-topped containers which makes unloading quick and easy. Efficient practices like this are a big part of the companies philosophy. In the factory, all the plasterboard off-cuts are recycled, precise manufacturing methods means that there is little waste and any rubbish is sorted and recycled. This means that the build stage generates little more than two skips worth of ‘rubbish’, most of which is recyclable packaging.
Find out more at
www.macc3.fr
www.hanse-haus.com or request information by emailing info@hanse-haus.com
Or write to
HANSE HAUS GmbH
D-97789 Oberleichtersbach
Ludwig-Weber-Strasse 18
Germany
Tel - +49 (0) 9741 808-0
Fax - +49 (0) 9741 808-119
Is a passive house right for me? Answer ‘Yes’ to the questions below and you should certainly think about building a passive home:
Are you looking for a home that offers low running costs and a comfortable modern living environment?
Is reducing carbon emissions part of your building agenda?
Are you prepared to spend a little more than the cost of a standard build?
Some FAQ’s
If I have a passive house, can I still open the windows? Of course! Although the central ventilation system means that this is not really necessary.
Are passive houses more expensive than normal houses? The initial build cost may be slightly higher. However the long term savings on energy costs will balance this out. Building to passive house standards will also increase resale prices.
Why are passive houses relatively uncommon in France? There are a large number of factors that have to be taken into consideration during the construction and planning phases and there are comparatively few companies who operate in this field. Now Hanse Haus are beginning to start building here, you can expect to see far more passive homes being built in France.
Even if you don’t opt to build an entirely passive house, you can still incorporate some elements into your build:
Site the property in a position that will maximise solar gain from windows
Install maximum levels of insulation in walls, floors and the roof
Choose triple glazed doors and windows
Minimise cold bridges - attention to detail is key, remember even a door lock on the front door can act as a cold bridge, so can a cat flap!
U values measure heat loss so the lower the U value the better! The thermal conductivity of the materials is calculated and then expressed as a formula of watts per square meter, per degree Kelvin, W/m2k. The calculation is based on the combined thermal resistances of all materials in the element. For example, calculating the U value of a window would include the glass, frame and fixings.
Before the house is delivered, the foundation slab will need to have been poured. This is generally done by a local builder or macon, who will work to detailed drawings supplied by the construction company.
Words - © Catharine Higginson
Photography - © James Higginson
There are others that will though, there was an Estonian company at a recent trade fair I went too. Name eludes me for the moment.
I contacted the company and the response I received is on orders from their parent company they no longer operate on France, so won’t even send me a brochure…
Wow, really interesting, we want in a few years to build just such a house for our retirement as our current place is beautiful but not practical for us when we are older…thanks forposting the link
No plans to do that Peter, we visited their factory, they have a very impressive setup.
Impressed by the Piefkes. James, are you going to rep them in France?
7 years ago we designed and built a low energy house in Exeter. From an affordability point of view we went for maximum insulation rather than utilising ‘alternative’ heating solutions. It worked very well but, in retrospect, and if I had to design another, I could have improved upon this for very little extra outlay. The main house was timber framed for the internal structure and stuffed with a double layer of Rockwool, but there was also a non-wicking insulation in the cavity and a urethane foam backing to the plasterboard. The 1st floor exterior part of the wall was ‘Thermalite’ block with battening over that supporting a timber-grained fibrous board that was most effective in being the front line against the elements. The heating was underfloor, with a total of 6” of insulation beneath. The roof was ‘Unilin’: rigid panels incorporating their own rafters and 6” of high density foam. This formed the upstairs ceiling - also clad in insulated pasterboard for the most part.
But the big surprise was my built-in workshop at the street end of the house: with the same board on the outside, then 100mm Thermalite block, an air space + 50mm high density foam in the cavity then 140mm Thermalite block on the inside, the underfloor heating only ever cut in in the very worst of Winter - even if the huge (insulated, of course) double doors were open for a while. The revelation was that the inner skin of Thermalite block was very effective at retaining the heat: acting as a store. It was also a revelation how rapidly the brickies could whack up the block, because of its light weight: one wall of 10mtrs x 2.6mtrs went up in 2½ hours from their arrival to departure. The speed of that construction more than compensated for the extra cost of the blocks.
Despite recently upgraded construction requirements, I’m still seeing buildings going up all over the place with masses of poured concrete. Hmm, might just as well carry on gluing the rocks together with good old lime mortar. Having lost that house to the UK ‘credit-crisis’, that’s what we’ve ended up with now: a typical, hard to insulate, old stone house. Oh well, renovation time! Won’t be Hanse Haus-ing anytime soon.
Happy to swap ideas and clink a glass or two with anyone who’s thinking of a new build.
We’ve been looking at self-build for some while and have made contact with some timber-frame companies, but this is a few steps infront of that so will definitely be looking into this some more when the time is right - hopefully in the not-too-distant future.
We were really impressed with the set up there and if we were doing a new build would def. go this route. The factory was something else!
Can’t understand why we are still sticking tiny bits of clay together, often in bad weather conditions, installing several tons of wood at a dangerous height and then enclosing a large space, which is not used except for storing junk, with thousands of bits of slate or plastic to make what we call a home. Generally with housebuilding we are living in the age of the horse and cart. Imagine if our homes were engineered and built to the same standards as modern cars and incorporated the technology. I think it is even worse here in France with single concrete blocks with sheets of plasterboard plus a bit of polystyrene stuck onto the interior walls and several miles of expensive copper wire in the smallest of houses. And there are no building inspectors! Our neighbour got to window level by following the ground contours - the house is on about a 15 degree slope - then put cement on top to level it off! Of course when it is covered in rendering no one can see the botched foundations.
I feel re-motivated. Am checking out their site. Thank you guys.
We are pretty much stuck with what we have for now, and given that it is mitoyenne we aren’t in a position, physically or financially, to knock down and rebuild.
However, were I building on a vacant plot I’d certainly look at this type of house. I don’t understand why more people are not yet doing this.
The geothermal heating can be a bit of a problem, in terms of the space needed and the subsequent restrictions on use of the land, though I guess that for such low energy consumtion the area needed would not be huge.
WOW this is fantastic! Thanks so much for this information. Makes me want one of those houses!