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Buildings passivhaus 101

Published on June 30th, 2013 | by Zachary Shahan

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Passivhaus 101

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June 30th, 2013 by Zachary Shahan 

I think we must have written about the Passivhaus (aka Passive House) concept a few times before, but I’m pretty sure we’ve never done a good overview of what a passivhaus is. Luckily, our friend (and longtime reader) Lindsay Wilson of Shrink That Footprint just put together such a piece and sent it our way to share with others. Interestingly, despite it having a 101 or introductory focus, some leading passivhaus experts have given it high compliments. Congrats to Lindsay! Check out the full post below or over on Shrink That Footprint. (Btw, sister site Green Building Elements also put together an intro on the passivhaus concept a few years ago.)

passivhaus 101

By Lindsay Wilson

Are you excited by insulation? No?

Would you like a house with virtually no heating bill? Yes?

Have you heard of a passivhaus? They’re quite wonderful.

 

A passive house (passivhaus) is a super insulated energy efficient home. The reason why you should want one is they have tiny heating bills, minimal carbon footprints, are flooded with natural light, and enjoy superior levels of comfort to normal homes.

Maximising gains and minimising losses

The simplest way to really get the genius of a passivhaus is in terms of heat gains and losses. Because a house remains roughly the same temperature over the course of a year, heat gains are equal to heat losses (it’s the law).

Heat gains come from a heating system, the sun’s warmth, and internal gains from things like appliances and people. Heat losses occur through the walls, floor, roof, windows, and doors, or via ventilation in the form of air leakage.

If you take a look at the graphic at the top of this post, you’ll see three types of houses represented by their heat gains and losses as they might be in Nothern Europe, the top half of the US, or any other temperate zone. In each case, the heat losses match the gains. Look at the losses in each house and you can understand what makes the passivhaus special.

The leaky house has solid walls, poor loft insulation, an uninsulated floor, single glazed windows and lots of draughts. Because of this, it needs 300 kilowatt-hours of heating for each square meter of space per year (kWh/m2a) just to stay warm.

The modern house has insulation in the wall cavity and loft, an insulated floor, double glazing, and some draught excluders. Because of its better insulation, it needs just half the heating of the leaky house, 150 kWh/m2a, to maintain a similar internal temperature.

The passivhaus has superb insulation in all materials, triple-glazed windows that face the equator to maximize solar gains, and is so air tight it uses a ventilation system to keep the air fresh. It needs just 15 kWh/m2a of heating, some of which comes from heat recovery in the ventilation system.

Because of these qualities, a passivhaus has a tiny heating bill. That means a tiny carbon footprint too. There are now more than 30,000 of them around the world. They come in all shapes and sizes. They can be new build or retrofit, and have merit in both cold and hot climates.

Not just insulated but comfortable too

A passivhaus is a funny mix of rocket science and common sense. The technology used in a passivhaus costs more than in a typical home. To build a new one, or meet the retrofit standard, requires great materials, careful design, and contractors that understand things like air-tightness and thermal bridging.

It is easy to look at the additional costs of a passivhaus and question the payback, particularly for a retrofit. But there is much more to a passivhaus than the trade off between upfront costs and heating bill savings.

Take one step inside a passivhaus in the dead of winter and you’ll get it. The passivhaus is all about superior comfort. In most houses, some parts are too cold, others areas too hot, while some bits are just right. A bit like Goldilocks and her porridge. Not so in a passivhaus.

In a passivhaus, every square meter is close to the temperature you want it.

And comfort is truly valuable!

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About the Author

spends most of his time here on CleanTechnica as the director/chief editor. Otherwise, he's probably enthusiastically fulfilling his duties as the director/editor of Solar Love, EV Obsession, Planetsave, or Bikocity. Zach is recognized globally as a solar energy, electric car, and wind energy expert. If you would like him to speak at a related conference or event, connect with him via social media. You can connect with Zach on any popular social networking site you like. Links to all of his main social media profiles are on ZacharyShahan.com.



  • Mike_Hohmann

    Why stay passive – get active: follow Rolf Disch at http://plusenergiehaus.de/index.php?p=home&pid=8&L=1&host=1

    • Matt

      MIke I do think the first goal is to get you power needs as low as possible by doing the passive home and then adding on the PV planes is a great two-fer. If you don’t reduce your power needs you need a lot more PV panels.

  • Derp

    Someone should make a demonstration hotel. Most people get their ideas for their house from being in someone else’s.

    • ThomasGerke

      I think the first certified “Passivhotel” was build in 2010/11 in the German Alps.
      It’s zero emissions building and meets its electricity needs from onsite solar, as well as local biomass & hydro power.

      Here’s a picture:
      http://www.ahgz.de/bildergalerie/pics/170/580×500/explorer-hotel-montafon_4481.jpg

      BTW: It’s a budget hotel ;-)

      • Mike_Hohmann

        Budget hotel? Look at its energy budget: an energy-plus building par excellence! No wonder they can charge budget prices :-) !

  • Kelly

    http://waldseebiohaus.typepad.com/biohaus/design.html the first vertified passivhaus in North America…at the Concordia Language Village camp in Bimidji MN. It’s really coo…kids get to live in it and learn about how their actions affect the footprint. You should look in to it, Zachary. I believe it is availabe for meetings and use duing the off-season. Everything in it and about it is really interesting.

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