Solar Access

We looked at many properties before we found the site where we wanted to build the ZEH. The main criteria with regard to solar access when choosing this site was that it had little to no shading from large trees or surrounding buildings. This meant that we could make full use of the sun to heat the building in the winter, helping us to achieve one of our main goals of avoiding the need for spacing heating.

Configuration of the building on the site

One of the first steps of the design process was to work with A Design Studio to define the ideal building footprint on the site. Our criteria were:

Maximise usable and sunny garden space for outdoor living and growing vegetables and fruit
Maximise winter solar gain to the building for natural heating and light
Allow for spaces that interact with the street front and neighbours, but also spaces which are private
Maximise opportunity for natural ventilation
Ensure there would be a north facing roof space for solar PV modules and hot water collectors

We considered a number of different configurations, three of these are shown below.

North west facing L

U facing 30° west of north

Rectangular building facing 30° west of north

The layout that we finalised on was an L shape facing with the main living area facing NW as shown below. This configuration has the following benefits:

As the site faces 30° west of north it maximises solar gain along the north elevation where most of the living spaces are located
Creates a courtyard in the front of the site that will be sheltered from the prevailing SW winds
Maximises garden space with direct sunlight
Maximises solar potential for PV and SHW

Configuration of internal spaces

The internal spaces were then arrange based on solar access and use as follows:

Kitchen located for morning sun to allow a sunny warm space for breakfast
Living areas used mostly in the afternoon or evening, so located for solar gain during these times of day
Dining area may be used at any time in the day so is located for sun throughout the day and also near the kitchen for convenience
Each bedroom located so that it has access to the sun at some point during the day, i.e. along the north side of the building
Transient or less frequently used spaces where internal temperatures are not so important, such as hallways, bathrooms, laundry etc, located along the south side of the building