What Is PassivHaus?
PassivHaus is a voluntary design and construction standard for buildings that are energy efficient, comfortable and sustainable. Originally developed in Germany, it has since been widely adopted in the UK. The standard focuses on reducing heating demand, improving insulation, and creating buildings that require very little energy to run. PassivHaus homes maintain a stable internal temperature with minimal reliance on conventional heating or cooling systems.
PassivHaus buildings are based on a set of performance-based criteria rather than specific materials or construction types. There are five core design principles:
Super Insulation:
Walls, roofs, and floors are insulated to a much higher level than typical UK Building Regulations. This helps reduce heat loss and maintain consistent internal temperatures. All insulation must be continuous and free from gaps.High-Performance Windows & Doors:
Windows and doors used in PassivHaus construction must meet strict thermal performance standards. Typically, this means triple glazing and well-insulated frames that limit heat transfer and air leakage.Airtight Construction:
Air leakage is tightly controlled, with the entire building envelope designed and built to minimise unwanted drafts. The PassivHaus standard requires air permeability of no more than 0.6 air changes per hour at 50 Pascals.Mechanical Ventilation With Heat Recovery (MVHR):
Because the building is so airtight, fresh air is provided through a mechanical ventilation system. The MVHR unit extracts stale air and recovers heat from it before drawing in filtered, pre-warmed fresh air from outside.Thermal Bridge-Free Design:
Construction details are carefully designed to avoid thermal bridging at junctions and connections. This improves overall energy performance and helps prevent issues such as cold spots and condensation.
PassivHaus Certification In The UK
In the UK, PassivHaus certification is managed by the Passivhaus Trust, which works alongside the Passive House Institute (PHI) in Germany. Projects are assessed against set performance criteria through detailed modelling using the PHPP (PassivHaus Planning Package) software. Certification is available for new builds, retrofit, and large buildings such as schools and flats.
How We Can Help
At Energy & Design Ltd, we provide technical support for PassivHaus projects across England, Scotland, and Wales. We work with Architects, Developers, and independent Contractors to help deliver successful PassivHaus builds from early planning through to certification. Our services include: PassivHaus Feasibility Advice, PHPP Modelling & Energy Calculations, Construction Detailing & Thermal Bridge Analysis, in addition to Certification Support & Documentation.