To get a warmer, high-performance home, the first thing people think of is increasing the amount of insulation. Thicker insulation than Building Code minimum is important. However, did you know that insulation must also be continuous to be truly effective?
Gaps in insulation are like gaps in your ski suit when you’re on the slopes. Cold comes in and your heat goes out. And, like a lovely cosy ski suit, the thing with thicker insulation is that heat goes out gaps even faster because you’re warmer inside.
In addition to the discomfort and higher bills, the trouble with heat leaving your home through gaps in the insulation is that you get a cold spot in the structure. Cold spots are where condensation can form and over time mould will grow.
This often happens in places in the building structure where you can’t see it – until it becomes a major issue, that is. And by then it could be affecting your health and the durability of your house.
Where insulation is left out is one type of gap, the other type of gap is where a solid material goes through the insulation – like the edge of a concrete slab. This is a “thermal bridge” or “cold bridge” – where a material that conducts heat bridges between the warm cosy inside and the cold outside. (Read more on thermal bridging here.) Literal gaps in the construction where cold draughts come in is another kind. (Read more about draught-free construction here.)
If you already have a design, the easiest way to check if your home is designed for the insulation to be continuous is to use a red pen to draw over the plans and sections from your architect or designer. Or ask them to. The red line of insulation should be a continuous loop in any drawing. High-performance windows and doors are part of the insulation line.
If it’s not continuous, you should ask why and insist it gets corrected. You’ve got to get it right at the design stage to have any chance of it getting built right.
You might need to educate your Architect or designer if they aren’t familiar with high-performance design.
This is one of the topics, I often find myself discussing during an Expert Consultation where we review your project feasibility together. An Expert Consultation is the ideal first step towards commissioning me as your architect or engaging me as your specialist consultant (or Passive House designer) for the high-performance aspects of your design if you’re already working with an architect or designer. It’s a straightforward service for a very reasonable fixed price. All the detail are here.
A continuous (red) line of insulation ensures a high-performance outcome. (c) VIA architecture
“Passive House” refers to the international Passive House Standard, sometimes also referred to using the German spelling “Passivhaus”.
The Passive House Standard is often referred to as “the world‘s leading standard in energy efficient design.” And usually, a description of the standard includes details of the specific technical requirements.
The Passive House Standard is an international, rigorous, scientific, performance standard for the design and construction of energy efficient buildings. It applies to all kinds of buildings, not just houses. However, the Passive House Standard is not just about the technical requirements of energy efficient design, it encompasses:
What do Comfort, Energy Efficiency and Quality Assurance mean in practical terms for a house that is certified to the Passive House Standard?
A house that is certified to the Passive House Standard provides exemplary comfort all year round. While the standard is most well-known for rigorous energy consumption benchmarks, it also has rigorous comfort benchmarks.
The Passive House Standard ensures that a house can be affordably and reliably kept at a comfortable temperature all year round. This is true in hot periods of the year and in cold periods. The actual temperature inside the house is up to you though – some people prefer a cooler house, others prefer a very warmer house.
The comfortable temperature inside the house includes all the rooms and the surfaces of walls, windows and doors, etc. The Passive House Standard requires high-performance windows and doors so that the frames and the glass never feel cold to touch or be near. This also has the benefit of eliminating condensation, which can lead to mould growth and associated health risks.
The Passive House Standard ensures that a house is quiet inside and does not suffer from draughts.
The Passive House Standard ensures that a house always has plentiful clean fresh air. A ventilation system is required in most climates to comply with the standard. This means that even when it is cold and windy outside, or hot and dry, there is still fresh air silently and gently blown into the rooms of the house at a comfortable temperature. Windows and doors can still be opened whenever you want to, just like any other well-designed house. Equally important though, windows can be closed whenever you want to and there will still be plenty of fresh air throughout the house.
A house that is certified to the Passive House Standard uses very little energy to stay exceptionally comfortable all year round – and for you to do all the other things that you would expect to in your house. The Passive House Standard accounts for all the energy use in a house, from the heating and cooling, the cooking and lighting, through to TV and computer use.
Passive House ensures that your house uses very little energy because of the way it is designed and constructed. It does not rely on adding renewable energy generation systems to provide (or offset) some of your energy needs, although this is possible. It also does not rely on you making dramatic changes in your lifestyle to use less energy.
The result is that a certified Passive House could be using up to 90% less energy that an average house. And it comes with exceptional comfort, far better than any other house. Even compared to a typical new house, which is expected to be more energy efficient than average, a house certified to the Passive House Standard would expect to use up to 75% less energy. And this means power bills reduced by up to 75% also!
What good is a standard that doesn’t live up to its promises? (Or a Building Code, for that matter?) The Passive House Standard is one of the very few sustainable design standards that has a robust and reliable track record of delivering what it promises – exemplary comfort and radical energy efficiency.
Passive House requires that the Passive House Planning Package software (PHPP) be used to model the house and the energy use. The PHPP is a very detailed spreadsheet developed by the Passive House Institute. It reliably and accurately predicts how much energy will be needed to keep a house comfortable at the required benchmarks.
The Passive House Standard requires that an independent third party, the certifier, check the energy modelling (PHPP) as part of the certification process. They also check key aspects of the design including construction details.
The Passive House Standard also requires that the construction process is monitored to ensure what gets built matches the design accurately and that the builder takes personal accountability. Visual inspections are carried out as well as blower door tests to check the quality of construction. Where changes are needed, the energy model and details need to be updated and checked also.
These all add up to a very robust quality assurance process. Designers and builders are more vigilant knowing their work will be checked and verified. And honest mistakes can be picked up and corrected before something gets built wrong!
And it needs all three aspects. Energy efficiency is meaningless if your house isn’t comfortable and pleasant to live in. And a standard is meaningless if it doesn’t deliver what it promises. A house that is certified to the Passive House Standard will keep you comfortable and pleasant all year round with hardly any energy bills to pay!
The Passive House Standard is the benchmark for exemplary comfort, radical energy efficiency and reliable quality assurance.
Prospective Passive House homeowners often have a lot of questions. And rightly so, there are many new things to know about designing, building and living in a Passive House compared to a typical Kiwi house.
One regular question is: can we get a Passive House Cat Door?
The answer is: Yes
There is this very high-tech option from petWALK in Austria. It is designed for use in airtight, houses with controlled ventilation, such as a Passive House. It comes in a variety of sizes, colours, designs and with numerous accessories. It is suitable for both cats and dogs, installation in solid walls, glass, doors.
Price tag: starting around USD $2,000 with many more expensive options (depending on the option chosen and shipping)
There is also this more basic options from Freedom Pet Pass in the United States. Which, although it seems very basic and would need checking on a specific Passive House design, has been used for a Passive House in the US. There are 3 cat sizes and also options suitable for dogs.
Price tag: USD $239 – $359 (depending on the option chosen and shipping)
So a Passive House Cat Door (or Cat Flap) does come with a relatively hefty price tag.
Still, maybe your favourite moggy (or doggy) is worth it?
Do you have a question about Passive House? Please get in touch and ask away.
Passive House architecture can transform your quality of life by providing optimum living conditions with minimal energy costs. Most NZ houses have poor-quality indoor air, are cold and draughty in winter and too hot in summer. For your health and quality of life, your home should have excellent indoor air quality all year-round, should be draught-free, and should be pleasantly warm in winter and pleasantly cool in summer. Passive House architecture ensures these outcomes for your quality of life and peace of mind.
If you’re thinking of building a new home, make it a Passive House.
Transform your quality of life, VIA architecture.
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