The term Passivhaus (passive house in German) refers to a building standard that is truly energy efficient, comfortable, affordable and ecological at the same time. It results in ultra-low energy buildings that require little energy for space heating or cooling. Passivhaus is not a brand name, but a construction concept that can be applied by anyone and that has stood the test of practice.
- But a Passivhaus is not merely a low-energy building concept.
- Passivhauses offer also high level of comfort. They harness internal energy sources such as the solar energy entering the building through the windows, making heating systems much more efficient.
- Special windows and a building shell consisting of highly insulated exterior walls, roof and floor slab keep the desired warmth in the house. A heat recovery system allows for the heat contained in the exhaust air to be re-used.
- A ventilation system regularly supplies fresh air enduring superior air quality without causing any draughts.
Passivhaus buildings demand meticulous attention to detail during both the design and construction phases to accord with the principles developed by the Passivhaus Institute in Germany. CampbellReith’s most recent Passivhaus certified project was Octavia Living’s development at Sulgrave Gardens near Shepherds Bush, known as the Greenhauses.
Andrew Tullett, CampbellReith partner responsible for the project, explains: ’Passivhaus dwellings are a viable and cost effective proposition in urban locations. This project is the largest Passivhaus development in London, representing a significant step forward in proving that Passivhaus is both achievable and affordable, even on challenging constrained urban sites.’ Architects, building services engineers and sustainability consultants are often seen as the key design team members influencing the success of a potential Passivhaus project: so one could be forgiven for questioning the importance of the role of the structural engineer in delivering a Passivhaus certified building.
On closer examination, the structural engineer can be seen as vitally important to the future success of the project. Andrew continues: ‘There are significant benefits in having a structural engineer involved who has a good understanding of Passivhaus and the importance of the role of the structural engineer in the design process.
This is about taking a ‘whole building’ approach, by which I mean adopting an approach which takes into account the interactive effects, recognising that the different components which make up the finished building are linked together and cannot be considered in isolation. The secret of delivering successful Passivhaus projects is the understanding that the whole solution is greater than the sum of the individual parts. The building should be considered as an integrated system, ensuring that all components work in harmony rather than against each other.’
Truly integrated design is a key element in a successful Passivhaus project: the structural engineer, as part of the integrated design team has a vital role to play, being in the unique position to influence design simplicity, thermal continuity, airtightness and more. ‘The structural engineer can have a significant impact on achieving the Passivhaus standard.
They can assist in rationalising the design, simplifying details and increasing the cost effectiveness of the final solution. However, in order to make a positive contribution they need to have a good understanding of the Passivhaus principles and see their role within the wider project team. It is important to recognise there is not one set formula for successful multidisciplinary collaboration for the delivery of a Passivhaus project. It is vitally important that all team members keep an open mind, avoid assumptions and continuously challenge themselves and their fellow design team members to embrace the design constraints and construction quality control process.’
By Andrew Tullett, Partner at CampbellReith