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DownloadWith energy costs soaring and Scotland's net zero target fast approaching, we all need to be using less energy. We discuss the top 5 benefits of a Passivhaus home.
Developed in Germany over 30 years ago, Passivhaus (or Passive House in English) is not a brand or product. It's the world's leading standard in energy-efficient construction, guaranteeing affordable homes with amazing indoor comfort and radical savings on heating bills.
Passivhaus homes are so well designed, constructed, insulated and ventilated that they require minimal heating and maintain an almost constant internal temperature - cool in the summer and warm in the depths of a chilly Scottish winter.
For people who suffer with allergies and asthma, Passivhaus homes are the world's healthiest and most comfortable to live in. There are no draughts, cold spots, mould, condensation or overheating. A constant supply of fresh clean air is quietly pumped to the home and this happens with minimal energy usage.
In fact, a Passivhaus reduces heating demand by 79% compared to homes built to current Scottish building regulations. It might sound like magic, but the Passivhaus standard is a robust, science-based approach. 30 years of studies and testing have proved Passivhaus delivers what it promises - healthy, comfortable and easy to heat homes with lasting quality and guaranteed performance.
Rather than solely rely on bolt-on eco-technologies to generate energy, Passivhaus concentrates on reducing the amount of energy required to operate a home in the first place.
It takes a ‘fabric first' approach to energy efficiency, meaning the home's high-quality materials and components (the building fabric) do the hard work.
Passivhaus design centres on five key principles, and these must be integrated into your home to achieve the standard.
Passivhaus construction starts with generous amounts of high-quality insulation wrapped around your home in a continuous layer. Similar to a giant thermal sleeping bag, it plays a big role in reducing heat loss and keeping your home cool in summer. Many natural insulation options can be used, like wood fibre, stone wool, sheep’s wool and cellulose.
Windows are typically a weak link in homes, easily letting heat in and out. For this reason, Scotland’s Passivhaus homes use high-performance, triple-glazed windows. Triple glazing adds a third pane of glass to standard double glazing. This extra layer helps trap warmth inside during winter and prevents overheating in summer. The air spaces between the panes of glass are filled with Argon gas which works as both an acoustic and thermal insulator. Outside noise is minimised and windows aren’t cold to the touch. This keeps your home comfortable and stops condensation, which can lead to mould growth and associated health risks.
Passivhaus homes must be extremely airtight, with a target far more demanding than regular Scottish homes. This doesn’t mean your Passivhaus is tightly sealed and lacking fresh air – you can still open the doors and windows. Airtightness simply means unintended air leaks have been reduced to a minimum. Precautions are taken to tape and seal all gaps around doors, windows, electrical outlets, pipes and lights. Essentially, anywhere an air leak could occur, Passivhaus makes the extra effort to plug it.
This eliminates heat escape, cuts down on energy demand and provides exceptional indoor comfort, with no draughts, cold spots or overheating in summer. It also prevents moisture, mould and humidity building up, which protects the building structure and extends the life of your home.
Now the Passivhaus is airtight, it needs to be ventilated. The answer? A mechanical ventilation with heat recovery unit (MVHR). This extracts warm, moist air from bathrooms, kitchens and utility rooms and replaces it with fresh, filtered air from outside, resulting in excellent indoor air quality 24/7.
A heat exchanger ensures the incoming air is near enough the same temperature as that which has been pushed out, so you don’t feel any cool draughts.The ventilation system is also whisper-quiet and must meet strict noise limits.
A thermal bridge is a weak spot in a building envelope, often resulting from gaps, too little insulation being used, or the insulation being penetrated by a material with higher thermal conductivity (ie- wood). A bridge then forms between the inside of your home and the outside world, causing heat to escape and energy to be wasted. It’s like having a cosy blanket with a small hole – even if the rest of the blanket is warm, that little opening lets warmth sneak out. In a Passivhaus, any edges, corners, connections and penetrations are carefully planned to avoid thermal bridges.
Passivhaus takes energy efficiency to an entirely different level.
Most of the home’s heat is supplied by ‘passive’ sources, including sunlight, the body heat of occupants and running appliances, ie - boiling the kettle, watching tv, showering and cooking. Any additional heat required is supplied by a sustainable system, such as an air source heat pump.
Passivhaus home has 79% less heating demand compared to a home built to current Scottish building regulations. For you, this means hardly any heating bills to pay.
Thick, fully insulated walls and triple-glazed windows work to keep a Passivhaus at a stable, year-round temperature of 20°C, as it’s considered the optimal temperature for human comfort.
The MVHR system monitors for healthy temperature and humidity levels around the Passivhaus to make sure that the rooms aren’t too humid or dry. The best thing about the MVHR is that its filters remove dust, pollen and pollutants from the incoming air. People with asthma, allergies, hayfever and eczema reported their symptoms reduced or virtually disappeared after moving into a Passivhaus.
Passivhaus homes are proven to stay comfortable for up to seven days during power and heating cuts and are 50% quieter than conventional homes.
Passivhaus residents report high levels of satisfaction with their homes.
The energy we use to heat our buildings is a major contributor to climate change, responsible for a large portion of the U.K.’s carbon emissions.
To tackle this, the Scottish Government has set a target to reach net-zero emissions by 2045, with the rest of the U.K. aiming for 2050. A successful transition to net zero will require every household to cut their energy use by improving their state of repair, upgrading insulation and replacing oil and gas boilers.
These energy improvement works are known as 'retrofitting' and the costs will be huge, likely £33 billion in Scotland alone. Grants are available to help, but homeowners will be expected to pick up part of the bill. Even many new homes built today aren't energy efficient enough and will require retrofitting in the near future. Homes that don’t upgrade could become either unsellable or reduce in value.
Passivhaus homes are optimised for net zero. They’re fit for the future and will require little to no upgrading. You won't need to worry about replacing boilers, upgrading insulation, or dealing with high heating bills. Older properties are likely to decline in value, while highly energy-efficient homes will become more desirable.
Passivhaus-certified homes have recently seen a 5-15% rise in market value, proving that buyers are willing to pay extra for energy-efficient properties.
NatWest research supports this, showing that more buyers are placing greater importance on a home’s EPC (energy performance certificate) rating. Amid escalating costs of running a home, energy efficiency is now essential for buyers.
What good is a standard that doesn’t live up to its promises? To qualify as a Passivhaus in the UK your home must undergo a strict compliance process with an independent third party: the certifier.
The certifier provides impartial verification that all Passivhaus criteria have been met. They check the design drawings and energy calculations, they check what’s built on site and ensure it accurately matches the design.
This process is much more rigorous than the typical building regulation inspections and represents the best interests of the homeowner. Designers and contractors are vigilant knowing their work will be checked and verified throughout.
Once it’s confirmed your home meets the criteria, you receive an official Passivhaus plaque. This can be fixed to your home, proving its world-class qualifications.
The key reason we love Passivhaus is that no other building standard delivers results so reliably and the fact it can be checked and verified against a set of criteria is so important.
The energy performance gap (the difference between how a building is designed to perform and how it subsequently does once built) is a well-documented problem in the U.K. construction industry. Many new homes underperform, largely due to poor build quality and lack of quality control.
Passivhaus guarantees absolute correspondence between the expected and actual building performance, with little to no performance gap. Energy savings predicted from a Passive build are real, not just on-paper figures.
We believe this matters most for our clients because Passivhaus provides certainty and confidence - you know exactly what you're getting. Achieving the Passivhaus standard demonstrates a quality construction process and guarantees your home will perform as expected.
A trained communicator, Clare co-founded Coldwells Build with the aim of improving consumer experience within the construction process. Working previously as a television director and journalist, she understands more than most, about the power of detail, organisation and timing.
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A self-builder's guide to finding the perfect plot, evaluating its suitability and understanding the legal considerations involved.
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