Stunning Modern House Is Made From Straw Bale

Front of house
credit: Nicolas Koff

Architect Peter Eisenman once said "green’ and sustainability have nothing to do with architecture." Lance Hosey, in his wonderful book The Shape of Green, explains why:

Many believe sustainability deals exclusively with energy efficiency, carbon emissions, and material chemistry—issues that belong in a technical manual, not on a napkin sketch. Nuts and bolts are not exactly the stuff of every designer’s dreams. As a result, many consider great design and green design to be separate pursuits, and in fact much of what is touted as "green" is not easy on the eyes. The ugly truth about sustainable design is that much of it is ugly.

Well, if not ugly, perhaps not really well resolved. That's why I like Nicolas Koff's new house near Hamilton, Ontario. It takes the greenest of building materials, straw bale, and builds a very beautiful contemporary and modern house. Perhaps too modern, but more on that later.

credit: Nicolas Koff

I discovered the house in the British website Dezeen, where Koff explains:

"As physicians, the owners of the house were interested in healthy living and sustainability," said Koff, who was commissioned by a pair of doctors to create the house. "For this reason the house uses natural materials, traditional construction methods, modern technology, and barrier-free design principles to create a sustainable, healthy living environment that facilitates ageing at home."
credit: Nicolas Koff

The house is built out of a prefabricated straw bale system developed by Evolve Builders Group who have been using it to build very green school portables, the subject of another post coming soon. They build the wall panels and stuff them with straw in their factory. The panels have the structure necessary to hold up the second floor and the roof. The benefits of straw are many; it is a really good insulator and it absorbs and releases moisture in a way that keeps the interior comfortable all year round:

The house, situated adjacent to a conservation area, is constructed of 16" thick prefabricated straw bale walls, creating a breathable yet optimally insulated building envelope. The house can be heated through a set of high- efficiency fireplaces which channel heat throughout the house, and cooled through proper cross-ventilation. Photovoltaic panels located on the roof provide enough electricity to offset household consumption (including optional cooling and heating if ever required).
credit: Nicolas Koff

The cladding of the house is a mix of contrasting materials, white plaster and black shou sugi ban.

credit: Nicolas Koff

Shou Sugi Ban is our material of the year on TreeHugger; the ancient Japanese technique of preserving wood from rot and insects has become all the rage on the west coast, and is beginning to spread east.

credit: Nicolas Koff

The white portion of the house is plaster, and is my one worry about modern design in straw bale that I alluded to earlier. Most straw bale designs have deep roof overhangs to keep the wall dry; this house has almost no roof overhangs at all, unusual in conventional houses but more so in straw bale. I asked Nicolas about the composition of the wall and he responded, noting that he was confident it would work.

On the white portion of the house, the straw is shielded by a layer of magboard (seams taped), covered in a Keene rainscreen/air gap. Some areas more susceptible to water infiltration were additionally shielded using Typar or Tyvek homewrap. A metal lath was then added to the walls to support the plaster. Finally the plaster was coated with a white silicate paint that renders it hydrophobic.

So the plaster, which on most straw bale is applied directly to the straw, is in this case applied on lath with a drainage layer behind. The plaster itself is protected by "a fiberglass-reinforced magnesium oxide cement board, specially formulated as a structural sheathing, that is resistant to fire, water, rot, mold and termites." Sounds legit.

credit: Nicolas Koff

Inside, the house has a plan that is carefully designed for aging in place- a big ground floor master bedroom (3) and wide open living spaces. The architect explains:

All necessary amenities are located in a barrier-free environment on the ground floor (accessible from the outside through ramps), allowing the owners to age within the comfort of their own home. K-House’s main bathroom design was awarded first place in the Duravit Dream Bath Competition for its ability to combine accessibility, sustainability and minimal design.
credit: Nicolas Koff

The living room, kitchen and dining is all one big glorious space.

credit: Nicolas Koff

Our slideshow format has a real bias toward horizontal photos so you will have to take my word for it or go see the other photos on Dezeen.

credit: Nicolas Koff

It probably seems odd to some that the house would be heated with wood stoves, but the insulation from such thick straw bale walls is almost to passive house levels, The windows appear to be carefully placed and not overly large, and the house probably doesn't need much heating at all. I suspect it may be tough getting out of bed some winter mornings though, which is all part of "making seasonal changes integral to the experience of the place."

credit: Nicolas Koff

There is so much that is intriguing about this house. People will argue about whether heating with wood is sensible or green, and probably about the wall details. I worried about these issues and consulted with a British straw bale expert, who felt that the wall details were just fine, and as for heating with fireplaces,

Our experience of log burning stoves in our straw bale builds is that the clients invariably end up opening the windows when they fire them up! As a result they rarely get used, our houses relying on passive solar heat gain for most of their heating requirement. Of course, the UK is a lot milder than Canada...

Lance Hosey quotes Germaine Greer: "The first person to design a gracious zero carbon home will have to be a genius at least as innovative and epoch-making as Brunelleschi." We are certainly getting close.