Top 5 Benefits of a Passivhaus Home: Why You Should Build One
With 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.
What is a Passivhaus or Passive House?
Developed in Germany, 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 energy savings.
Homes built to the rigorous standard 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, Passive Houses 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 pumped to the home and this happens with minimal energy usage.
In fact, Passive Houses use around 75% less energy than the average new build. It might sound like magic, but the Passive House 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.
How does Passivhaus work?
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 building itself does the work. Super-insulated and airtight, it requires little energy to run, because it's effectively sealed against the elements.
Passive House design centres on five key principles, and these must be integrated into your home to achieve the standard.
What are the key principles of Passivhaus Design?
Passivhaus design starts with continuous, high-quality insulation wrapped around the home's entire shell, including the walls, roof and floors. This creates an ‘envelope' around the building, like a giant thermal sleeping bag. This high level of insulation reduces heat loss, making it possible to warm the house without a traditional heating system. It also keeps the house cool in summer. Superior insulation materials are also environmentally friendly, with options like wood fibre,sheep's wool and cellulose.
The Passivhaus Standard focuses on creating an airtight building, 15 times more demanding than minimum building regulations. Precautions are taken to tape and seal all gaps around doors and windows, electrical outlets, pipes and lights. Essentially, anywhere an air leak could occur, the Passivhaus building process makes the extra effort to plug it. Airtight design limits heat escape, cuts down on energy demand and promises superior comfort levels, with no draughts, condensation, or cold spots. Passivhaus creates a healthy environment.
No Thermal Bridges
A thermal bridge is a weak spot in insulation, which forms a ‘bridge' between the inside of a home and outside world where heat can escape and be wasted. This could be due to a break in insulation, or the insulation being interrupted by a material with higher thermal conductivity, such as wood. Thermal bridging is one of the most significant sources of heat loss in UK housing. To combat this, Passive Houses are carefully designed to reduce gaps in insulation where warm air can escape.
Windows can be a weak link in a home, either through heat loss or heat gain. Therefore, energy-efficient windows are vital to achieving the Passivhaus Standard. This typically means using triple-glazed windows that are as high quality as possible. The size and position of windows are also critical, as Passive House buildings are optimally orientated and designed to make the most of natural light and heat.
Ventilation System That Can Recover Heat
Once the Passive House is air-tight, you need a way of flushing the stale air out and replacing it with fresh, filtered and temperature-managed air. The answer is a mechanical ventilation with heat recovery system (MVHR). The MVHR removes any stuffiness in the home and eliminates the potential for condensation in cold weather. It does this through a heat exchanger which ensures any incoming air is near enough the same temperature as that which has been extracted from the home. This contributes to far better indoor air quality than in conventional homes.
What are the benefits of living in a Passivhaus?
Radical Reductions in Energy Bills
Building to the Passivhaus Standard drastically reduces the energy consumption of your home. Naturally, this equates to lower heating costs and in today's volatile fuel market, that's a huge advantage.
Quiet and Comfortable
In Scotland, Passive Houses are generously insulated, with triple glazed windows, superior levels of airtightness and ventilation systems. Insulation and airtightness seal the home, like a vacuum flask, keeping the house quiet and cosy year-round. Although high performance levels are required for passive house construction, the standard still offers a good degree of design flexibility to meet a homeowner's individual needs. Passive House residents report high levels of satisfaction with their homes.
Future-proofed Modern Houses
To tackle the climate emergency and achieve genuine emissions reductions, Scotland is accelerating legislation to meet its 2045 commitment for net zero homes. From next year (2024), all new builds will need to meet the Passivhaus standard, or a Scottish equivalent.
This change to building regulations is a great leap forward and acknowledges that Passivhaus is optimised for a net zero society. Passive Houses are designed for longevity, to meet all their needs from renewable energy sources, and will require little to no upgrading in future - saving homeowners on costly and disruptive retrofit projects.
Building a Passive House is a smart investment and will pay dividends for years to come. Designing energy efficiency into your home reduces your eco-footprint and operating costs.
Higher Sales Value
With high energy prices continuing to make headlines, buyers are now paying almost 16% more for highly energy efficient properties. Passive Houses can deliver greater financial returns. They represent not only a technologically equipped dwelling, but one that achieves construction quality - built to survive years of use, thanks to their robust building envelopes. Passive Houses are attractive to buyers and investors, as they are more durable and require less maintenance than conventional buildings.
To qualify as a Passive House, a building must meet a compliance process with an independent accredited certifier. The certifier supervises the process from the beginning, firstly checking the drawings and calculations in the design stage. They then inspect what's built on-site, ensuring it matches the design accurately. When the certifier is satisfied that all criteria are met, the homeowner receives a Passivhaus certificate and plaque. These steps add up to a robust quality assurance process, much more rigorous than the current building regulation inspections. Designers and builders are vigilant knowing their work will be checked and verified.
What are the advantages of Passivhaus buildings?
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 UK construction industry. Many new homes underperform, largely due to poor build quality and lack of quality control.
Passivhaus is the only building standard in the world which 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.
In early 2024, we will launch an exclusive range of contemporary, prefabricated, turnkey Passivhaus designs - the first of their kind in Scotland.
The six ready-to-go designs will be available in two, three and four bed versions and make it easy for self-builders, private clients, estate owners and developers to build a Passivhaus certified home.
The homes have been developed in collaboration with Scotland’s leading Passivhaus designers, John Gilbert Architects and will be manufactured in our Aberdeenshire workshop by our in-house Passivhaus-certified craftsmen.
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