....we should be able to avoid the need for heating the house for the vast majority of the year.

Building Envelope

In Auckland we are lucky enough to have a temperate climate, making energy efficient building design fairly simple.  A house that is comfortable all year round can be achieved with reasonable levels of insulation, reduced thermal bridging, summertime shading features and ventilation. The envelope of a house (i.e. walls, roof, floor and windows/doors) is a very important element of the design as it can have a huge impact on the energy performance of the building and the health and comfort of the occupants.

Thermal modelling of our preliminary design shows that with adequate insulation and high performance windows we should be able to avoid the need for heating the house for the vast majority of the year. The high insulation levels will result in uncomfortably high temperatures in the summer without adequate ventilation and shading which we will address through opening windows, eaves and other shading devices. This level of thermal performance has been demonstrated on projects like the Now House¹ which only needed heating for two days last winter.

Concept markup of building envelope features. The section shows the building when viewed from the east

Design Opportunities Matrix

The matrix below shows the key design considerations related to the building envelope in the left column and the project goals listed along the top. The coloured boxes indicate the goals that the design considerations contribute towards. The matrix is colour coded as follows:

•  Indicates that the design feature has a positive effect on the goal
•  Indicates that the design feature has a negative effect on the goal
•  Indicates that the design feature can have a negative or positive effect on the goal

The sections of the website listed in the top menu bar are evolving and details on the design initiatives will be added to these sections as we develop the design and build the house.

 

	Project Goals
Design Feature	Energy Efficiency & GHG	Low Embodied Energy	Water Conservation	Health & Comfort	Waste Minimisation	Low Pollutant Emissions	Durability
Well insulated thermally broken construction [more][details] Ensuring walls, roof and floor are very well insulated and select thermally broken frames and low E double glazing to minimise heat loss through the building envelope. This limits or removes the need for heating in the home reducing energy use and associated green house gas emissions and cost.
Natural ventilation and shading [more] Opening windows throughout to allow good natural ventilation. Allow for future addition of shading features to reduced solar gain on summer days. Use of vegetation over glazing to allow seasonal shading.
Optimally sized performance glazed windows [more] Size and location of windows in frequently used living spaces optimised for good daylighting and solar gain, but minimal heat loss. Low E double glazed windows specified. Good daylighting to minimise use of artificial lighting.
Green roof to entrance hallway [more] Provides thermal mass reducing internal temperature fluctuations Provides onsite stormwater treatment and control

 

Footnotes

1. Beacon Pathways : Now House Project