What is Passivhaus design?

Passivhaus is a method for designing and constructing buildings that:

• maintain a comfortable temperature all year round
• have excellent internal air quality
• use very little energy for heating
• use no additional energy for cooling (in a cool climate such as the UK)
• perform as they are designed to perform.

Passivhaus design by LEDA

Our Passivhaus design service is modelled on the Passivhaus Planning Package (PHPP). Whether you plan to build and certify your building to the Passivhaus standard or use Passivhaus design principles to achieve a low energy building, we can support your project with advice, design and specification.

Passivhaus principles can be applied to new or existing buildings. We can work with you to develop a robust ‘deep retrofit’ of an existing building as well as advising on new buildings. We can work with architects or provide architectural services in-house, and cover all work required to achieve quality and performance as the design progresses through the RIBA plan of work stages:

• Advice on site layout, building shape and orientation
• Modelling of the building in the Passive House Planning Package (PHPP)
• Development of building details
• Thermal bridge modelling (when required) and advice on reducing bridging.

Does a Passivhaus build require different materials?

A Passivhaus building can comprise many forms of construction and types of insulation. The primary requirement is that data is available on the performance of the materials, so the building can be accurately modelled in the Passivhaus Planning Package (PHPP). This requires more detailed specification than non-Passivhaus builds at the planning and construction stage. LEDA can provide training and guidance to help construction teams navigate this part of the process.

What features need to be included in a Passivhaus design?

Perhaps the most significant features of Passivhaus buildings are the highly insulated floor, walls and roof, which depend on the orientation, shape and size of the building. Triple glazed windows are used as they offer high insulation and comfortable internal surface temperatures. Passive House ventilation is mixed mode – for the winter months, mechanical ventilation with heat recovery (MVHR) is used, with natural ventilation (opening windows) in summer.

How can I achieve Passivhaus certification?

There are strict criteria for achieving Passivhaus certification, the full list of which can be found here. We are strong advocates of Passivhaus design and with our own Certified Passivhaus Designers, we are a reassuring authority on all aspects of low energy building design and securing Passive House certification.

Talk to us about your Passivhaus or low energy build project, or for more insight, visit a Passive House property near you at one of the twice-a-year open days.