Recently, we touched the very tip of the iceberg on how the 5 main elements of passive solar design work together to make your home more energy-efficient. While solar energy and energy-efficiency are all relatively modern topics that have gained real momentum in recent years, the science of passive solar build design is not at all new. It’s really simple, yet amazing physics figured out by folks a very long time ago. 

Good passive solar design provides optimum thermal comfort with minimal use of artificial heating or cooling – and in some climates, can potentially reduce your usage to almost nothing.

#Tip: Passive homes require you to have a general understanding of how the home ‘works’ with the daily and seasonal climate, like knowing when to open or close windows, and how and when to adjust shading.

Here are some simple ways use passive design in your home.

Design according to climate

Strategies used for ultimate passive design depend on the climate as well as the aspect and attributes of the building site. Australia has 8 main climate zones, each with its own characteristics that dictate the most appropriate design. 

The Greater Sydney region is in the Warm Temperate climate zone, for example, with hot to very hot summers and mild winters. There is no one-size-fits-all so you’re best to engage the services of an expert if you’re passionate about getting the best results.

Orientation

Passive design utilises the sun and cool breezes as natural sources of heating/cooling by orientating the home appropriately and designing the building to minimise unwanted summer heat or heat loss in winter. 

In a warm climate, living areas with large banks of windows should ideally face north to take maximum advantage of the sun. Likewise, the direction of breezes are considered, placing windows and doors directly in its path so fresh air can flow freely and easily through.

Shading

Direct sun can generate the same amount of heat as a bar heater per square metre of surface. Effective shading reduces temperatures internally, improves comfort and saves on energy. 

Because the sun sits higher in summer, the eaves, adjustable shading, external awnings, roller shutters, and leafy plantings provide additional shade, protecting the home until later in the day. Plantation shutters have excellent insulative properties for optimal energy-efficiency. 

Permanent shading needs to be properly considered because it will potentially block out the winter sun also.

Passive solar heating & cooling

Most Australian climates require both heating and cooling and it helps to know the specifics of the climate zone you’re in to achieve this. 

Consult an expert to discuss how best to capture and retain the warmth of the winter sun, while allowing the built-up heat of the summer sun to escape.

Sealing

Sealing your home and eliminating drafts is one of the simplest ways to maintain internal temperatures and reduce energy usage, with air leaks accounting for 15–25% of winter heat loss. The more extreme your winter, the more beneficial sealing is.

Insulation

Insulation acts as a barrier and is an essential element for keeping your home warm in winter and cool in summer. A well-designed and insulated home provides year-round comfort, reducing heating and cooling bills by up to half (heating/cooling accounts for around 40% of household energy consumption). 

Glazing

Up to 40% of a home’s heating energy can be lost and 87% heat gained through improper glazing.

Windows and doors provide natural light, fresh air and connect interior spaces with the outdoors. However, they can be a major source of unwanted heat gain/loss, making your insulation efforts null and void. 

This can be largely overcome with the right glazing – double glazed windows are excellent at reducing energy consumption considerably. 

Skylights

Skylights can make a major contribution to energy efficiency, comfort, and, research shows, to the value of your home. They are an excellent source of natural light, perhaps generating more than three times the light of a vertical window.

Do you have anything to add? Let us know by leaving a comment below. 

While the science or physics behind it is relatively simple to understand, ‘passive solar’ build design is an intricate topic that we couldn’t possibly cover in one article. However, it’s worth discussing because by incorporating passive solar principles into your next home – even loosely – you’ll have a home that is not only beautiful but comfortable, cheaper to run, easy to live in and naturally energy-efficient.

While Merit Homes are experts in the art of luxury homes more so than the complicated elements of passive solar builds, to varying degrees, the principles are incorporated into every one of our homes. A standard of energy efficiency in all new homes is required by law, and it is undoubtedly an area of strong focus for us, our contractors and our clients too. It’s worth considering now because the most economical time to achieve good passive design in a home is in the initial planning, design and building stages.

Read on for a very brief explanation of each passive solar design element, and come back to see simple ways to incorporate them into your next home.

The light collector – ‘Aperture’

The light collector refers to large, sun-facing glassed (windowed) areas in your home at which sunlight can enter the building. In Australia, the ideal aspect for windows to face for optimum use of natural sunlight is to the north. 

Natural light streaming through your home is not only beautiful and a natural mood enhancer, but it serves two purposes for energy efficiency. Great use of natural lighting means you can use artificial lighting less, and sunlight also adds warmth, reducing the need for additional heating in winter. 

In Summer, the sun sits higher in the sky, so wide eaves help to reduce the amount of sunlight and heat entering the home.

The Heat Absorber

This is a hard, darkened surface, which could be a masonry wall, floor, or water container, that sits in the direct path of the sunlight and absorbs heat throughout the day, storing it in the ‘thermal mass’ behind. 

The Thermal mass

The thermal mass is the material that retains or stores the heat produced by sunlight. This could be a sun-facing brick wall or a concrete slab. The ‘absorber’ is the dark outer surface exposed to the sun, the thermal mass is the material beneath this surface that retains the sun’s energy (heat) that it will release into the home throughout the day.

The Distribution

This is the method by which the stored energy or heat collected in the thermal mass circulates throughout the house. This may include fans or ducts, or just the natural behaviour of the thermal material – a wall, for example – which radiates warmth collected throughout the day into the home overnight.

Control

Here’s where the design is controlled to suit the season. The sun hangs lower in winter, so although the climate is cooler, sunlight is able to penetrate through sun-facing windows well.  In summer, the sun sits higher in the sky, so the home’s eaves (roof overhang) shade the sun from the light collector and heat absorber, allowing less heat to penetrate inside. 

Another example of the control element is airflow and ventilation. Take advantage of the breeze by placing windows to capture and circulate the cool air throughout the home.  

Next up, we’ll discuss ways to use passive design principles in your next home.

Building a new home often goes down as one of the most stressful events in one’s lifetime – and most often, you’re not even the one that has to build it!

There are so many reasons why building a home from the ground up can lead to stress and anxiety due to delays, mistakes and unbudgeted expenses.

Believe it or not, a lot of these occurrences can be avoided with a little extra thought, care and research at the early planning stages of the project – starting with choosing the right team for the job.

Here are just a few of the things to factor in when selecting the right builder for your dream home.

What’s your budget?

Your budget is integral to the type of home you can build. And because builders specialise in particular types of builds – from first home to mid-range, high-end custom builds to very high-budget luxury homes, your budget is also key to deciding the builder you’ll use.

Ask around

Reputation is everything. We recommend asking around your friends and family for their experience, and if possible, talk to someone currently building. Listen carefully to their responses.

Are they happy? Why? Why not? Do they feel listened to and understood? Are they easily contactable? Any major problems or conflicts? Are they happy with the workmanship? How has the builder responded to their concerns?

Do they specialise in the type of home you want?

Now that you have a shortlist of reputable builders, you need to know if they specialise in the type of home you want. Being a great bloke means nothing if he can’t deliver the home you had envisioned in the timeframe you’d expected.

Inspect their work

Inspect a near-complete current project, or ideally, an older home that’s been put on the market. How is the workmanship holding up after a few years of being lived in? Are there any major cracks or visible defects to the structure? Do the fittings and fixtures still look high-quality?

Are they local?

This one isn’t so obvious because, within reason, most builders aren’t averse to going outside of their usual trade area, and custom builders like Merit specialise in constructing homes that are ‘out of area’ daily.

However, it’s worth considering because when a builder is too far outside of where they’re comfortable, it can mean they have fewer options available to them when it comes to trades, suppliers or materials, which can mean delays or additional expenses.

Reduce the chances of blowing the budget by selecting a builder experienced in your area, OR, one that’s confident working in all areas like Merit Homes.

Are they registered? Licenced? Insured?

It’s so important to ensure your chosen builder is a legitimate, reputable company. At the very least, they should be a registered builder, licenced to work in the construction industry, have Public Liability Insurance and Home Building Compensation (HBC) – previously Home Warranty Insurance (HWI).

Because regulators can be slow to catch up with those not doing the right thing, you can ask the Housing Industry of Australia (HIA) or the Master Builders of Australia (MBA) for their list of members.