I have tried my hand at Passivhaus before, attempting to write about the subject on some very basic knowledge and what I can pull out online. However, it’s not been up to scratch. So, I went to Twitter to see if there was anyone out there heavily involved in Passivhaus work. It turns out there was and they have been kind enough to write a guest post for DGB giving some accurate information and a proper introduction to the standard. It’s a pretty informative one and worth a read!
What I do and where I come from.
My name is Mark McLean and by trade I’m an Architectural Technician, specializing in Energy Conservation and Passivhaus Technology, based in Fife Central Scotland.
Over the past 5 years building regulations within the UK have become far more stringent in terms of energy conservation and renewable building technology, noticing a gap in the market, I, with the help of William Walker established Callum Walker Energy Source and The Callum Walker energy Centre. A showroom and center of excellence that specializes in renewable technology and integrated energy saving solutions for new and existing buildings.
The UK with its ever-changing Building regulations is slowly but surely catching up with its continental cousins, adopting key attributes of the German Building Standard “Passivhaus” so…….what exactly is Passivhaus and how can it benefit the way in which we build and live in our conventional British homes?
Lets start with the basics, what is a Passivhaus?
“A Passive House is a building that heats and cools itself without a conventional heating system. Space heating is generated through passive sources such as body heat and the sun.”
The Passive House (or Passivhaus) Standard was originally developed in Germany around 20 years ago and is based on creating both comfortable and energy efficient buildings”
How do we achieve the PassivHaus standard, and how much will it cost?
A Passive House is a building that is designed and constructed to a strict set of criteria to ensure maximum comfort with minimum overall energy consumption. The building fabric is detailed in such a way that heat loss is reduced to an absolute minimum, whilst heat gains are maximized. As a result, conventional heating systems can be removed and space heating can sufficiently be supplied through passive sources such as body heat and the sun.
A Passive House takes the fabric first approach to design and construction. The reduced energy consumption of 85% compared to conventional buildings is achieved by an enhanced building fabric which combines super insulated floor slab, walls and roof, superior air-tightness, thermal bridge free design, quality approved Passive House windows and doors along with a quality approved Passive House mechanical ventilation with heat recovery system (MVHR) which will recover 95% of the buildings internal heat gains.
It is observed that a Passive House in the U.K. can cost from 8-15% more than a conventional building. These additional costs come through the upgraded building envelope and mechanical ventilation system. However, over the lifecycle of the Passive House this increase in capital costs is eclipsed by the dramatic savings made due to reduced energy consumption and the almost non-existent heating bills. Construction costs will of course continue to reduce as the U.K.’s construction sector experience grows within this rapidly expanding industry.
The intention to build a Passive House and seek certification must be established at the outset of a project. The process of planning and detailing a building to Passive House Standard demands consideration of the Passive House requirements at every stage of the design.
Is the Passivhaus theory a novelty and a gimmick?
In short, absolutely not. The UK at the moment is the furthest behind in terms of building technology compared to continental Europe, however we are the fastest at catching up.
This is not surprising really when you take into account the following facts and figures:
- The average Swedish cowshed uses less energy and is better insulated than the average UK home.
- 35% of a buildings heat loss is lost through poorly manufactured and sub standard Double-Glazed windows, which at the moment are a standard building element.
- An average UK home produces 9.2 tonnes of CO2 per year and uses up to 280 kWh per year, compared to 15 kWh of energy usage in a passivhaus and 0.6 tonnes of CO2 (basically a passivhaus is over 18 times more efficient and cheaper to run than a standard UK home).
- Energy costs within the UK are constantly rising and have done so month on month and year on year for the past 5, and they are only set to get higher.
Taking the above, all be it basic facts into consideration, we would have to pretty ignorant to ignore the fact that we have to take action to lower our energy costs and usage.
I cant afford to build a Passivhaus, how can I reduce my energy costs?
Its not always possible to find land, appoint architects and design your dream home, after all I’m a realist…..it all costs money!!
However we can take some very basic and simple steps to reducing our energy costs and making our homes more energy efficient, here are my 5 simple steps to making your home more energy efficient.
- The most important element which makes up the fabric of any house is the windows, today it is very easy to get hold of Triple glazed windows, they don’t have to be Passivhaus certified, however, look at the “U Value” (the elements thermal efficiency) the lower the u value the better, standard double glazed windows have a u value of around 1.8 – 1.6, where as standard triple glazed windows have a u value of around 1.0 – 0.9. This can make a massive difference in the air tightness of the building and its overall thermal efficiency.
- Have a look at your lighting within the house, a standard bulb, even the “energy efficient” ones have an average wattage of around 30 – 60 watts where as modern LED lighting has an average consumption of around 4 – 6 watts.
- Boilers – Now this is complicated and possibly expensive issue, but look at the basics has your boiler been serviced lately? Can you afford to replace it to a SEDBUK A rated boiler? or can you look at changing the boiler to a renewable heat source like a bio-mass boiler, air source heat pump or geo-thermal heat source? The more self efficient you become the less you will rely on costly fossil fuels.
- Insulation – Another of the important factors in any building (second only to windows), there are lots of Government funded schemes available now for loft, cavity, EWI (external wall insulation) and IWI (internal wall insulation) if you are eligible for free insulation upgrades then take advantage!! it can make a massive difference to your homes running costs and more importantly its air tightness (the better the air tightness the more efficient the heat loss and the lower the heating demand).
- Tariffs – This is perhaps the most simple of steps to take, thanks to the wonders of the Internet, simply go online and make sure that you are on the best possible Energy Tariff that your provider can offer, websites like “The Energy Saving Trust” & “Money Saving Expert” have fantastic free resources that can assist in changing provider.
I hope the above gives you a very brief insight into how you can take advantage of the Passivhaus theory and make your home more energy efficient.
If you need more information on Passivhaus, energy efficient building elements or integrated energy solutions please do not hesitate to contact me and I would be more than happy to answer your questions or queries.
Tel: 01383 415 914
Passivhaus is something I really want to get more involved with, and is something I think the UK should be embracing to really improve the new housing stock. 8-15% more to build a Passivhaus building I think is an acceptable amount extra to pay when you consider the long term benefits of almost no utility bills during the lifespan of the house.