Anyone who has ever tried to gift wrap a teddy bear can appreciate the simplicity of a rectangular box. After all, a box allows for maximum paper coverage with a minimum of wasted material and a final product that is attractive while still being totally functional. Furthermore, with the addition of a few pieces of cardboard, you can partition the interior of a box to hold various smaller items separately in a large number of configurations without compromising the integrity of the structure. In this way, the basic rectangular box can hold a wide array of items and even be custom designed to hold specific items.

 

This is the simple premise behind the design of the Mau Passive House.

 

The Mau House is a simple rectangle with a hipped roof that straddles the house, rather than sitting atop it. This means that, like a box, the interior of the house is essentially one room. Also like a box, the roof is affixed to the outer walls of the house, eliminating the need for load bearing walls. The practical upshot of which is that interior spaces can have any dimension needed by the client, because walls can be placed anywhere.

 

Another advantage of this design is that without the need for interior walls in specific locations, eliminates added complexity, thermal bridges and leaky envelopes that are common with more complex designs.

 

A thermal bridge is created when there is poor insulation between the interior and exterior of the home. This could allow heat to escape and condensation to form. With the simple rectangular design the number of possible bridges is minimal and easy to control because there are only four walls that require the necessary detailing. If there is a load bearing wall intersecting with an exterior wall in a simple “T” formation, then the number of surfaces that have to be insulated against the thermal bridge triples. Naturally, this increases complexity and costs.

 

The Mau Passive House is going to be a retiring couple’s forever home, so future proofing the house is necessary. The halls are wider, to allow for any mobility devices should they be needed and the doorways and shower lack thresholds for the same reason. In the addition, the bath is set to be fitted with handrails should they be needed at a later date.

 

In keeping with the focus of reduced complexity, we are using a combination heating and ventilation system; thus removing an entire system from the home. Additionally the water heater we are using is an air-to-water heat pump that stores water at a higher temperature, which is then mixed with cold to bring it to the correct temperature for whatever is needed. This allows for a smaller, more energy efficient unit. All of these systems are extremely energy efficient systems and are easy to maintain.