Passivhaus buildings require minimal heating needs – typically 15 kWh/m2/yr – which can easily be met through energy efficiency measures and renewable technologies on-site.
Lower energy bills and emissions result from using this approach, while occupants can enjoy a comfortable indoor environment with fresh, pre-warmed air supplied via MVHR and passive solar gain.
Energy Efficiency
Passivhaus (German for “passive house”) sets very stringent energy efficiency standards for insulation and fabric first design of buildings, which allows them to consume up to 90% less energy than new build UK houses – quickly becoming a popular method of creating low energy homes.
To meet the standard, an approach utilizing software like Passivhaus Planning Package (PHPP) must be taken to design. Furthermore, renewable energies may help reach zero carbon emission via on-site renewables.
Passivhaus homes require very minimal space heating due to being well insulated and air tight; natural heat from sunlight, people and household appliances is enough to maintain an even temperature throughout the year and allows residents to heat it without using much or any mains electricity – though some will be necessary for hot water heating purposes.
Ventilation
Buildings consume 35% of global energy use – Passivhaus offers an effective solution to decrease this energy demand by taking an integrated fabric first approach with super insulation, airtightness, and careful attention paid to eliminating thermal bridges.
Ventilation systems offer constant controlled ventilation with heat recovery to maintain an ideal indoor environment with minimal energy input and effort. They also assist with condensation control, provide fresh filtered air supply and can lower noise levels significantly.
There is currently no single method for heating space in a Passivhaus; however, many use their ventilation system and add a small boiler for hot water. This ensures the fabric first ethos of this standard is met, without having to compromise performance of their building.
As certified Passivhaus Tradespersons, we can design, install and maintain mechanical ventilation and heat recovery systems to meet Passivhaus requirements. Contact us for more details.
Insulation
Passivhaus buildings employ high standards of insulation, which significantly decreases their energy requirements for heating. Instead, passive sources (sunlight, human body heat or household appliances) or supply air heating can supply all heating requirements.
Passivhaus construction involves using thick insulation materials – often several layers thick – in all its components to avoid thermal bridges and create an airtight structure.
Passivhaus buildings must also be designed to minimise peak heating demand, with annual energy use for heating, hot water and household electricity not exceeding 15 kWh/sq metre. Before certification by the Passivhaus Institut in Darmstadt Germany can occur, houses built to the Passivhaus standard must undergo testing process – many houses are built according to this standard; however only those that achieve certification will cost between 5- 10% more than traditional builds.
Design
Passivhaus design principles rely on detailed modelling software developed by the Passivhaus Institute to ensure an airtight building fabric, with greater investment made early on towards optimizing form factor (the ratio of internal floor area to external surface area). This ensures optimal insulation.
Passivhaus buildings strive to reduce space heating demands to levels where it can be met by incidental gains from occupants, cooking appliances or passive solar gain; this results in buildings that offer equal comfort both summer and winter with minimal environmental impacts.
Passivhaus architecture uses mechanical ventilation with heat recovery (MVHR) systems to provide constant, filtered, pre-warmed supply air for ventilation and heating (depending on climate zone). This results in lower energy bills than standard homes while simultaneously keeping humidity at bay, thus decreasing mould growth potential.