Improving the energy efficiency is an important step in designing new homes or remodelling existing ones. Not only does it save money and energy, but it makes your home more durable and more comfortable to live in. Not to mention more attractive to potential buyers down the road.
Remodel vs. new build
For a home remodel, the process starts with an energy audit, which will determine how your home uses energy and what are the best ways to reduce and rationalize its use. On the other hand, if your plan to design and build a new home or invest in an extensive remodel, tackling home energy efficiency calls for a whole-house-system approach, which will include all the variables, details and interactions that make up the energy use in your home. Apart from occupant behaviour, site conditions and climate these include insulation and air sealing, lighting and daylight, space heating and cooling, windows and doors, and water heating.
Calculating local climate
A sun path diagram of your site location will help you determine the orientations for your home by outlining where the sun travels in the sky throughout the day. However, you need to include all the obstructions around the site, such as buildings and trees, as well as potential obstructions, like vacant lots that could be developed in the future. If you’re anticipating an on-site windmill generator, a wind rose available at the Bureau of Meteorology, will tell you the direction and frequency of prevailing winds in your area. Finally, knowing your predominant sky conditions throughout the year is vital when determining how to illuminate the home’s interior, including the advantage of natural light.
Building orientation
Working with the data you’ve collected about the site’s sun, wind and light conditions, you can decide how to orient your home. Keep in mind, though, that the building’s shape will greatly influence the heating and cooling requirements. Buildings in hot, droughty climates experience large gains from the sun in the summer. However, if you shape the building in a way that reduces exposure to the sun, or shade the glass surfaces by large overhang and adequately insulate the walls, the solar exposure can be minimized. For the Northern Hemisphere, the best way to orient home is to face south. This way it will capture solar gain in the winter and block solar gain in the summer. It’s the opposite for the Southern Hemisphere.
Replace or update existing windows
Energy-efficient windows are critical for both new homes and remodels, since heat gain and heat loss through windows is accounted for between 25% and 30% of residential heating and cooling. If you determine that your existing windows are in good condition, while remodelling, you can increase their efficiency by caulking and weather-stripping, installing storm windows or adding solar control film. Apart from increased energy efficiency, advanced solutions, such as Magnetite double-glazing system, provide additional benefits like thermal comfort and noise reduction.
Benefits of cool roofs
A cool roof is designed to reflect more sunlight and absorb less heat than standard roofs. In its more basic version, a roof can be made ‘cool’ by applying a special reflective type of paint, covered by sheets or reflective tiles or shingles. Urban buildings with flat or shallow-pit roofs can benefit greatly from green roofs. Ranging from simple turf cover to true rooftop gardens, this type of roofing not only provides excellent natural insulation and manages stormwater but adds an extra outdoor space for occupants to enjoy.
Combining state-of-the-art energy-efficient building techniques and natural lighting with commercially available renewable energy sources, ultra-efficient homes take advantage of local climate and site conditions. Sometimes designers can even include passive solar heating and cooling, by exploiting energy-efficient landscaping strategies.