The key to having an energy-efficient home… Passive solar design

What is passive solar design?

By now, we are all aware of what solar energy is, and most people have a general understanding that solar energy is good for the environment and their own pockets. But, what exactly is passive solar design? The concept is pretty simple. Passive solar design takes advantage of your homes’ location, climate, materials, and more to minimise the home’s energy consumption. A well-designed passive solar home will reduce your heating and cooling needs with energy-efficient strategies which can be enhanced through the use of more active solar methods.

Passive vs Active solar design, what’s the difference?

Passive solar design is largely the strategies, techniques, and planned use of materials that are taken into account when designing your house and are constantly ‘at work’ upon completion as they are built into the structure of your home. For example; south-facing windows to maximise the sun warmth in your home. Whereas active solar design is something that you can choose to switch on or off, and has capped consumption available. Active solar energy can be sourced from solar panels that convert the sun’s energy into a more useable form, to then power your home. So you can get on with your day, boiling the kettle or having a hot shower.

The most important principles of passive solar design:

• Location and orientation

If the site has not yet been selected then this is a chance for you to consider your potential site’s exposure to the sun. For example, are there large trees on the property? Do the neighbours have a towering house that will block the sun? Is the property on a slope? Once you have a site, the exact location and orientation of the house within the property is a crucial decision. The ‘ideal’ location and orientation will vary across the country and from site to site.

• Thermal mass

Thermal mass is the ability of a material to store heat energy. High-density materials such as stone, brick, tiles, and concrete are effective in heat consumption and distribution. Because of the dense make-up of these materials, heat is gathered and stored. As the surrounding temperature lowers, the stored heat is gradually released over time to maintain the temperature of the room.

• Insulation

Insulation is key! When other design tools have been put in place to enhance the energy-efficiency of the home insulation must be planned and executed correctly. Otherwise, all that energy your home has been collecting and storing in passive methods will be lost and your design efforts will be wasted! Insulation slows the loss of heat in winter and helps reduce internal heat gain in the Summer. Effective insulation and the incorporation of passive design principles can drastically reduce the need for active space heating. In some cases, it can even remove the need for additional heating entirely.

• Ventilation

Passive ventilation is merely the system of refreshing the air within your house without the use of a mechanical system. Allowing existing air to be recycled outside and fresh air to come inside your home. This is done by harnessing the natural wind flow and temperature differentials within your home. This is suitable in most regions of New Zealand and is the least expensive and most environmentally friendly system of ventilating your home.

By choosing a designer to work with that understands the complexities of passive solar design means that you’re on the right track to experiencing a more comfortable, energy-efficient, and cost-effective home. Happy spaces equal happy faces.