A WELL SEALED HOME

 

In our last blog, we covered correct window shading and the use of thermal mass to stay warm in winter and cool in summer. This week, we are going to look at insulation and sealing, which again plays a huge role in keeping your house both warm in winter, but also cool in summer.

 

Insulation

Insulation helps prevent any unwanted heat from entering the house during the warmer summer months and also prevents heat existing your house during the cooler winter months. In the summer months, this insulation acts as a barrier to heat flow, preventing the unwanted hot air in summer from entering into the house through the walls, floors and even roof. During winter this insulation works in the opposite way, acting as a blanket to your home, preventing the warm air inside your home from escaping. Insulation comes in many different types and forms, with different varieties working better for different applications, depending on the location. Correct insulation should be used in all areas of the house for maximum result, there is little point in over insulating one area of the home to then neglect another. A good way to think about insulation within your house is filling a bucket with water, if there are no holes in the bucket no water will escape, however, if you place a hole in the bucket, the water will slowly escape and the more holes, the faster the water escapes. Your house is like this bucket, if you insulate your whole home, leaving certain areas uninsulated, the heat will find its way to this ‘hole’ and exit or enter. The more ’holes’ in your house (uninsulated areas) the faster the heat will escape or enter.

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Sealing

Air leakage is another factor to consider when building your own home. Air leakage can account for up to 20% of winter heat loss, along with a considerable amount of cool air lost in the summer months. Much like the bucket example above, sealing your house correctly works in the same way. Whilst it is still important for our homes to be correctly ventilated to ensure fresh air throughout, if this air leakage is minimised, ventilation can be controlled through desired openings to ensure no unnecessary warm or cool air is gained or lost.

Janik Dalecki
ALL YEAR ROUND COMFORT

 

Staying warm in winter and cool in summer, without auxiliary heating and cooling.

Two big factors in keeping your house both warm in winter, but also cool in summer are correct window shading and thermal mass.

 

Shading

Correct shading greatly reduces the inside temperature of your house throughout the warmer summer months, improving your comfort levels without any auxiliary cooling. However, did you know that incorrectly positioned and sized shading could also block out the warming winter sun, leaving you with a fridge for a house during winter?

Window and wall shadings are crucial in reducing unwanted heat gain during the hot summer months. Many people are unaware that unprotected glass is actually the greatest source of heat gain to a house. Effective shading such as window awnings or shutters, eaves, pergolas and even plantings can block up to 90% of the summer heat.

It is crucial that window shading be designed to block out all summer sun, whilst still allowing the winter sun to penetrate deeply into the home. This is easily done through correctly sized and located shading, paired with good planning and good design. Poorly designed fixed shading structures can end up blocking out the winter sun and natural winter heating, resulting in a cool house during summer but an even colder house in winter. During the winter months, the sun is at a much lower angle, which means that with the correct shading devices; this lower angle winter sun can penetrate through or under the shading and enter deep into your home. However, it is a fine balance with the specific shading for each specific window size, location and orientation.

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Thermal mass

Thermal mass is the ability of a material to absorb and store heat energy. High-density materials such as concrete, bricks, stone and even tiles require a large amount of energy to change their overall temperature. Therefore, they are fantastic materials to use to maintain thermal comfort within your home, when utilised in the right location. However, badly placed thermal mass can worsen the extremes of the climate by storing and radiating heat in summer and the opposite in winter. Good thermal design will moderate the indoor air temperature throughout all seasons of the year.

In winter, the thermal mass stores heat from the direct daytime sunlight and then releases this throughout the evening when the internal air temperature drops.  In summer, the thermal mass works the opposite way and should be shaded from direct sunlight. This allows the thermal mass to absorb internal energy from the heat within the air inside the house during the day. The cool night breeze then passes over the thermal mass, drawing out any daytime stored energy, which then in return, cools the overall internal temperature for the day to come.

As you can now begin to see, each of the individual passive solar design elements ties in with one another and, if each are not considered equally, then the overall balance is off. Each factor needs to be addressed and included to ensure your home operates correctly.

Janik Dalecki
2017 BDAWA OVERALL DESIGN EXCELLENCE WINNER

Whilst we have always thought that our project 'The Wasley' was a winning design, we are incredibly proud to say that this has now been made official. At the Building Designer's Association of WA annual Design Awards held on Saturday night, 'The Wasley' took home the award for Best Residential Alteration/Addition $350 - $800k, as well as a special commendation in the Best Heritage Design category.

On top of the above two accolades, we are extremely humbled and all round excited to be able to announce that Dalecki Design took out the overall Design Excellence award for the year! We are extremely proud of every single one of our projects, so to receive such an award is a huge honour.

 

 

Janik Dalecki
SELECTING THE CORRECT ORIENTATION

 

The orientation of your block plays a huge role in your eventual home design- much greater than what many would think.

 

 

Good orientation increases the energy efficiency of your home which in turn is both a huge step towards more sustainable housing, as well as a large reduction in the running costs of your home. With rising energy costs once again a hot topic of discussion, it seems a logical step to optimise the location of your house on your block, especially considering that optimal house orientation costs you no more than a little additional upfront thinking. 

Additionally, a well designed, well orientated house is much more comfortable to live in during both summer and winter.  In summer, a well oriented house is kept cool by minimising the heat gain into the house and capturing cooling breezes. Whilst in winter, a well oriented house is kept warmer through allowing the winter sun into the house and preventing any heat loss. 

 

BLOCK Orientation

One of the most important aspects is the orientation of the block itself. When selecting a block, you ideally want it to be elongated along the east-west axis, therefore having a larger north facing boundary. This increases the ability to maximise the homes northern outlook. In return, this means more rooms and windows facing north, and subsequently, the ability to capture and store the greatest amount of winter sun and heat.

 

Built environment

Along with the orientation, the current built environment should be considered when looking to purchase a block of land. Any existing buildings or trees to the north, no matter how small, will shade some portion of the north face of the house and will therefore dramatically affect the homes overall performance. 

For instance, a corner block with an uninterrupted north face will work very differently when compared to a block with a three storey house in close proximity to the north face. Both blocks may be elongated on the north face, however, the corner block with no overshadowing from any surrounding structures will provide a far greater end result than the block being overshadowed by the three storey home. During the winter months, the sun is at a much lower angle, so even a small obstruction to the north face can be quite detrimental to the function and operation of the house

Similarly to how the built environment plays a role with capturing the winter sun, it also greatly effects how the cool summer breezes are allowed to flow throughout the home (in Perth commonly referred to as the Freo doctor, or Fremantle doctor). These cooling sea breezes come from the South West, providing a cool relief to our hot Perth summers.  Wind paths are a little more flexible than the sun as these breezes can be manipulated and guided with wing walls and wind tunnels. However, if you have a large obstruction (for example a large house or apartment complex) in close proximity to the south west of your house, possibly even abutting your house, it will effect the ability to capture these cooling summer breezes.

As you can see, it is not as simple as only looking at the overall orientation of your block, but also the surrounding built environment in terms of how it will affect your home design.

A good designer that has the ability to think outside of the square can work in with any scenario to make the best of both the block orientation and built environment.

Stay tuned for our next post in our mini series on Passive Solar Design.

 

 

Janik Dalecki
PASSIVE SOLAR DESIGN
"The Wasley' featuring highlight windows to capture the cooling summer breezes designed by Dalecki Design.

"The Wasley' featuring highlight windows to capture the cooling summer breezes designed by Dalecki Design.

 

So firstly what is Passive Solar Design?

‘Passive solar design’ takes advantage of the climate to maintain a comfortable temperature range within the home. This is achieved through the appropriate orientation of the house on its site to make the most of natural heating and cooling.

House orientation is the key component to passive design, with spatial zoning, thermal mass, ventilation, insulation, shading and glazing also being contributing factors. Passive Design is a relatively simple strategy, intended to keep summer heat out and winter heat in, moderating the temperature of the home for comfort all year round.

 

Why should you include Passive Solar Design principles?

Passive Design can be easily achieved with upfront thinking and planning during the design phase of your home. The best bit is it’s free! It relies solely upon the heat from the winter sun and cooling summer breezes to achieve thermal comfort within the home. With Passive Solar Design you can reduce, or even eliminate the need for auxiliary heating and cooling, which accounts for approximately 40% of energy use in the average Australian home. The immediate energy cost savings you will notice in a Passive Solar designed home is just one of advantages to having a thermally comfortable home, whilst also knowing you are being considerate to the future of our environment.

Stay tuned and keep an eye out for our next post on your homes ideal orientation in relation to Passive Solar Design.

 

 

Janik Dalecki