Prefab homes that combine beauty with long-term sustainability
What defines an eco house? We look at the features, materials and construction methods that make pre-fabricated Passivhaus standard houses the perfect choice…
Keep hold of your heat
There are two features to take into consideration with eco houses. Firstly, the energy efficiency and carbon emissions associated with running the house, and then the type of construction materials used, their associated emissions and the raw materials required.
Baufritz have won awards relating to the sustainability of their houses, because, as a company, they have put environmental stewardship at the core of their ethos since the 1960s. So how do they do it?
Heating is the biggest variable emissions factor for any house. It’s really rather simple to solve this problem: make a house extremely energy efficient and it’s no longer a factor. Ultra-low energy houses may qualify as meeting the Passivhaus standard if they reach a certain set of design characteristics.
You need a very high level of insulation in the walls and roof. Glass should be suitably glazed and positioned to optimise solar gain (heat from the sun). The house needs to be very well engineered so no heat is lost through cracks or poorly fitted windows and doors. Baufritz manufacture kit houses and use modern manufacturing methods in their factory to engineer houses in a way that nothing leaks.
They have also developed ‘HOIZ’ insulation. Manufactured from natural wood waste products, HOIZ is placed between the inside and outside layers of their timber framed houses to create the highest level of insulation. Their windows and doors use triple glazing to minimise heat loss.
Overheating is one of the biggest challenges Passive houses face and the Baufritz architects use some very clever ventilation systems to manage internal environmental conditions. All houses still have energy consuming appliances, but with the addition of solar for both electricity generation and water heating, the carbon footprint can be further reduced.
Embedded carbon in building manufacturing materials such as concrete, as well as a historic tendency to send materials to landfill, results in a high carbon footprint and natural resource exploitation. Baufritz addresses this problem in a number of ways.
The primary manufacturing material is wood, sourced from sustainable certified forests where felled trees are replanted. In fact, they believe all building materials should be as natural as possible. They say no to PU construction foams, chemical insulation materials, toxic adhesives and laminate flooring. A house constructed using only natural materials, creates a healthy living environment for its residents.
As all their houses are manufactured in a state-of-the-art factory in Bavaria, waste is kept to an absolute minimum. At end of life, their houses can be recycled. Today, demolition firms clearing the site for the new build are able to recycle nearly all of the building materials, therefore closing the manufacturing loop.
By designing and building houses to ultra-low energy standards, and by using only natural sustainably sourced materials and recycling the waste products from manufacturing processes, Baufritz are able to deliver carbon neutral houses. This means the total carbon footprint throughout the life cycle of their houses is zero, which is why they are, undeniably, eco-house pioneers.