Orientation-zero-energy-home

Orientating your home to make the most of the sun’s energy can be the key to building a zero energy home

If you’re aiming to build a zero energy home then renewable technologies, triple glazing, and innovative insulation techniques may be at the forefront of your mind. But there’s one secret that can help you achieve the zero energy dream and it won’t cost you a cent. It’s all to do with where and how you position your home.

Of course, it’s impossible to create a home that uses no energy. We need it for basic survival; to cook, heat our home and for lighting. A zero energy home is therefore defined as one which produces enough renewable energy to meet its own annual energy consumption requirements.

As the amount of energy you’re able to produce on your lot is likely to be limited, zero energy homes are designed to make the most of passive energy. By this, we mean using natural heat (from the sun) and cooling (wind) to keep your home at a comfortable temperature. And that’s where the orientation of your home can make all the difference.

Orientation is simply the direction your home faces. It’s measured by the azimuth angle of a surface relative to true north. So if you have a wall facing due east, this would have an azimuth angle of 90 degrees.

In combination with massing (the size and shape of your home), orientation determines how much daylight your home gets, how much heat it can absorb in winter and if it stays cool in summer. If you design you home to take advantage of this, you’ll need less energy to heat and cool your home.

When should you consider orientation?

There are a couple of things to consider when thinking about your new home’s orientation:

  • The direction of the long axis.
  • The exterior size and shape, and interior layout of your home.

Both of these need to be thought about very early on as they will fundamentally affect the design of your home. You may even want to consider orientation when choosing your lot. The amount and direction of sunlight your lot receives, along with the prevailing winds, will determine how easy it will be to build a zero energy home.

What’s the best orientation for your home?

The best orientation for your home will depend on whereabouts in the world you are and whether you’re likely to use more energy heating your home in winter or cooling it in summer.

If you live in the northern hemisphere in a temperate climate, then you’re likely to want to orientate your home on an east-west axis. Parts of the home in which you want to maximize solar gain should face south, as these will gain the most light (and heat), particularly during the cold winter months. The afternoon and evening sun is hotter than the morning sun, so south-westerly facing rooms will typically get warmer than those facing southeast.

Conversely, north-facing rooms will receive little if any sun. It’s best to keep glazing to a minimum on this side of the building and focus on insulation to keep heat in. If you live in a particularly hot climate, you may want to reverse the orientation and layout to focus on keeping your home cool in summer.

However, energy consumption is unlikely to be the only factor influencing the design of your home. You may have great views you want to take advantage of, or a busy road you’d rather not see or hear. If you’re looking to install solar panels then you may want a roof area aligned to generate the most electricity or heat. Orientation is just one of many factors to consider when deciding on the design of your new home.

What if I have no flexibility?

Unfortunately, not all plots are created alike. If you have a small or awkward-shaped plot of land, then you’re going to be more limited in the choices you have around orientation.

If that’s the case then it’s even more important to consider how you optimize the layout and design of your home to make the most of what sun you get. For example:

  • Work out where the sun falls on your lot at different times of the day. Can you do anything to increase the amount of sun you get, such as removing vegetation that blocks the light? Make sure you take into account changes in seasons – the sun takes a lower path in winter than summer.
  • Based on this, decide where you want your large glazed areas to be. Think three-dimensionally; for example, if you have a restricted lot in a built-up area, you may be better off using skylights in the roof instead of a large glazed frontage.
  • Plan your interior layout around these glazed areas.

For more ideas on maximizing natural light when designing your home, have a look at this post.

Ventilation and shading

If you live in a temperate climate then you may focus primarily on maximizing solar gain to warm your home in winter. But you’ll also need to consider ventilation and shading techniques to make sure your home doesn’t overheat in summer. This is particularly important if you have a highly insulated, high performance home.

If you’re aiming for a zero energy home, you’ll need to rely mainly on natural ventilation systems. There are different types of natural ventilation, including wind ventilation, night-purge ventilation, and stack ventilation. Consult an expert to find the right solution for your home based on your local climate.

Shading can be built into the design of your home (e.g. covered balconies or shutters) or the surrounding landscape. For example, mature deciduous trees can provide shade in summer, but let through the winter sun to warm your home.

If you’d like to build a zero energy home, but need some technical support why not get in touch? We’re specialists in creating unique, high performance homes to suit a range of styles and budgets.