Building Passive House with Natural Materials

Recently I had the pleasure to see Bjørn Kierulf of Createrra Architects in Slovakia, give a presentation at BUILDEX Vancouver, about Passive Houses built with natural materials.

Natural Passive House
Driven by the desire to build Passive Houses as natural as possible, Bjørn Kierulf is building certified Passive Houses with straw panels, wood, cellulose insulation and clay plaster.


The main reason for wanting to use as many natural materials as possible, is because these would be non-toxic, and in todays building world toxicity is rampant.

Bjørn pointed out that in 1900 only 50 building materials were available on the market, while today there are more than 50,000 building materials, of which only 43% are tested for toxicity(!).


Clay Plaster
As well, he reasoned that clay plaster is a superior finishing product as it:
1. requires no chemical bonding,
2. controls humidity by its ability to absorb @>50% and desorb @<50%
3. and it’s creative!

Innovation Through Collaboration
Driven by the need for more economic, innovative components, Bjørn also collaborated with local product manufacturers to develop high performance windows, high efficiency HRV units and structural straw panels.


[Images used with permission from Createrra Architects]

Hajo Meijer

Hajo Meijer is the sole proprietor of Ecocentric Design, committed to deeply sustainable architecture. Hajo is a graduate from the faculty of Architecture at the TU Delft in the Netherlands and a certified Passive House Designer. Hajo lives with his family on Vancouver Island, British Columbia.

This Post Has 4 Comments

  1. Gerry Costello

    Hi Hajo:
    Are the walls in the first pic above prefabricated straw panels? Have you used these in a house in Canada? I am considering a passive house, and would like to use prefabricated straw panels but want to learn more about compliance with the National Building Code.
    I appreciate any info you can provide.


  2. Bowen


    I love what you are doing using natural materials and building passive house standard.
    Currently I am building my own house with hempcrete walls. It is a passive solar design, and I am also trying to achieve a good level of airtightness.
    With regards to the ceiling, I am using Intello below the rafters and want to seal down onto the rendered hempcrete walls. I’ve been looking at how to achieve the sealing.
    I’ve been advised to use spray foam in difficult to seal areas.
    As I’m wanting to use natural products, could you advise how to best the sealing of the Intello to the walls?

    1. Hajo Meijer

      Hi Bowen,
      My apologies for the tardiness of reply. I’ve been busy… There are products available to adhere membranes to masonry/concrete/rendered walls. I suggest to talk to a rep from 475 building supply or small planet building supply and I am sure they are able to help you. There are also special tapes you can render overtop to create a nice transition. I would definitely NOT use spray-foam as is will deteriorate over time and lose its airtightness.
      Good luck,

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