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For Homes that do not cost the Earth. 

Passive house is a comfort standard for buildings, which goes through a rigorous design process to ensure your home is healthy, thermally comfortable & energy efficient, resulting in a more pleasant living environment and reducing your living costs.

The standard works for New-Builds as well as for Retrofits. The EnerPHit standard simplifies the criteria to make it cost-effective to work with existing buildings. While certification provides independent quality assurance of the project, many of our clients use the Passive House criteria to make measurable improvements to their homes.

The main benefits to you are:


Passive houses have a constant stream of fresh, heated, filtered air, avoiding a build-up of stale air with toxic gases, smells & airborne pathogens.

We make the Passive house airtight to reduce draughts and increase thermal efficiency. Once it is airtight we use Mechanical Ventilation with Heat Recovery system (MVHR) to introduce the fresh air, in a controlled manner. This air is preheated using the heat from the waste heat to an efficiency of 90% and filtered to remove any external particles.

The fresh air, heated and filtered, is essentially healthier than the outside air. Opening windows for additional ventilation and breeze becomes a bonus rather than a requirement!


The added advantage of a well-insulated home is that it is thermally stable and comfortable all year round: 20°C – 25°C with a maximum of 10% overheating. With global warming, overheating is becoming a bigger issue for non-passive houses.


High-temperature heating systems like radiators usually heat traditional homes at 70°C. This causes significant temperature differences across a space, making it challenging to feel thermally comfortable. Most current houses are built, getting an airtightness test of between 3-10m3/hm3, and this can be equivalent to having a few windows open all year round.

With excellent airtightness, there will be no draughts, which makes us feel cold even when the room is otherwise warm. In a passive house, the spaces are less prone to temperature fluctuation, with internal temperatures maintained by solar gain, body heat & appliances with some top-up from a low-temperature heating source.


Studies on passive houses show there are fewer harmful gases present in a passive house compared to houses in a similar area.


Due to the build quality of a passive house, often the first thing most people notice when they walk into a Passive House building is how quiet it is.


With an active filtered ventilation system, a lot of the dust is removed in the ventilation system. Good for those with allergies!


Passive House ventilation systems extract moisture and odours from kitchens and bathrooms and exhaust them to the outside whilst constantly supplying filtered fresh air into the building. This also helps prevent mould growth – which can harm our health.


In most other building standards, i.e. Building regulations, there is often a “Performance Gap” between designed energy usage and actual performance once occupied. This is because when designing a passive house, every aspect of energy consumption is considered, and rigorous quality control occurs during the construction phase.

The rigorous quality control system throughout the design and construction phases of a Passive House means the build quality should equal the design quality. Therefore, actual energy use should be the same as the designed energy usage.


Passive House buildings have lower running costs than traditional houses. The annual space heating demand is 4-8 times lower than a standard new build.

Whilst the construction cost of Passive Houses is usually a bit higher than non-passive houses, the added upfront construction costs can be offset by savings in running costs.


A house built to Passive House criteria will lower your operational costs and carbon emissions, making it better for the environment and your purse.


Lustre House

Fforest Farm

Room in the roof

The Verandah

E: info@variantoffice.com

T: 0203 985 1381

241-251 Ferndale Rd

London SW9 8BJ