Is This Truly a Maintenance-Free House?

©. Jesper Ray

Reldania By and Byg is one very strange heritage preservation organization. The Danish foundation manages a portfolio of important historic buildings, but also invests in new ones, which have "a significant experimental character with respect to architecture, technology, or location." In Nyborg they have built six MiniCO2 houses,

six houses

© Realdania

"The impetus has been to demonstrate five extreme ways to reduce the CO2 footprint in five different houses, as a basis for developing the sixth house; a single-family Mini- CO2 standard house, combining all the lessons learned." TreeHugger previously showed the Upcycle House here and raised some questions about it.

Maintenance free House exterior

© Jesper Ray

The Innovative Maintenance-Free House, by Arkitema Architects, is one of two houses designed with the goal of lasting 150 years, with minimum maintenance for the first fifty. "The house was to be built of new and innovative materials that still have to prove their durability and reliability over time – or at the very least, the construction of the building had to be innovative."

Maintenance free House construction

© Jesper Ray

The house was prefabricated off-site to "ensure the necessary precision in the building components," and assembled in two days. So how do you make a wood house maintenance-free? According to Realdania

glass closup

© Jesper Ray

The whole house is enclosed in sheets of glass, on the sloping roof and on the vertical facades, protecting all degradable building components against rain. The wooden structure also had to be adequately ventilated in order to keep it dry, which is why the house is lifted half a meter [it says 30cm, or 1 foot, elsewhere] off the ground on stilts of concrete and why there is a gap between the plywood structure and the glass skin. The gap creates a natural chimney effect, sucking in air at the bottom and letting it out at the top of the roof. No complicated mechanical ventilation system is needed – natural forces are at work here.
Maintenance free House side veiw

© Jesper Ray

In Archdaily, the architects note that doors and windows are pulled back from the facade to protect them from the elements, which is good established practice. They claim that the recycled glass skin is indestructible. But can this glass skin actually protect the building?

Maintenance free House interior

© Jesper Ray

I wonder. I would have thought that the glass would act as a giant flat plate solar collector, significantly heating the plywood underneath. To create the natural chimney effect that ventilates it means that it has to be creating heat. To me, it seems like they have put the house into a giant solar oven. The architect writes that "The heat that is generated in the gap between glass and wood will be utilised in an extended ventilation solution, with the hot air saving significant amounts of CO2." Given that it is on the outside of what looks like a foot of insulation, I have my doubts that it will do anything at all, other than degrade the plywood underneath.

Then there is the question of putting the house a foot off the ground, high enough for animals to make a nice little nest but too low to actually get underneath to do any sealing or even basic cleaning. That certainly is not going to be maintenance free.

traditional house

© Realdania

Interestingly, another house in the product is the Traditional Maintenance-free house, built of tried and true materials but also designed to be maintenance free for 50 years and built to last 150. Hopefully TreeHugger will be reporting on the success of the project at its end, but I'm putting my money on the traditional house.