Designing healthy buildings for the future with Passivhaus

// sustainability

Increasing numbers of clients and developers are choosing to invest in Passivhaus realising it will deliver a building of real value. alsecco and Gale & Snowden are firm advocates of Passivhaus assured that the benefits are numerous to both owners and occupants whether they are homeowners, students or office workers.

With alsecco’s expertise in façade design through technically proven, high quality products and systems and Gale & Snowden’s approach to healthy building design, the two companies have joined forces to create a partnership approach to Passivhaus. Passionate about eliminating fuel poverty and providing healthy and energy efficient buildings, both companies have the ethos and capabilities to work with clients to deliver a cost effective solution built to the Passivhaus standard.

The partnership focusses on a holistic approach to Passivhaus giving clients the assurance they will be supported throughout the project from concept to completion and beyond. It offers an integrated and coordinated approach to schemes ensuring specific requirements are addressed and included, ensuring that Passivhaus design is in no way prohibitive in terms of design and creativity.

All components are sourced and supplied for both the exterior and interior. Relationships have been built with a wide range of reputable manufacturers and suppliers, only working with those companies concerned with sustainability and creating healthy Passive buildings.

Since Passivhaus describes a performance standard and not a specific construction method, the appearance of Passivhaus buildings including houses can blend in perfectly with their conventional neighbours. Whilst Passivhaus buildings must meet specific energy demand targets, building designers are free to choose how best to meet them. This is typically achieved through high levels of insulation, exceptional air tightness, high performance windows and doors and highly efficient mechanical ventilation systems with heat recovery (MVHR).

The benefits to occupants of housing built to the Passivhaus standard are numerous and provide a compelling argument. Not only are the properties comfortable characterised by an ambient indoor temperature throughout the year with no draughts or summertime overheating, but use very little energy, a huge plus for owners and residents. The ongoing costs of Passivhaus buildings are usually greatly reduced when compared to conventional buildings, translating to lower energy bills and offering protection from future energy price rises. With early adoption, optimal orientation and a compact form, Passivhaus buildings can be delivered at costs that will compete with those of similar conventional buildings.

Healthy design should be at the heart of good design for both buildings and landscapes. It is important to carefully consider both how buildings are designed and the choice of materials used in the key elements of the design.

Our approach is to minimise the need for complicated and expensive active systems in buildings by the correct and intelligent employment of simple passive design techniques. By employing sound building physics from concept to detailed design we are able to produce simple passive solutions. This allows us to significantly reduce mechanical engineering equipment which can often be over designed, which in turn enables low running costs and buildings that are easily maintained.

We want to ensure that our buildings use as little energy as possible. Current Building Regulations place too much emphasis on low carbon strategies and technologies at the expense of low energy building design. By concentrating on a low energy, fabric-first approach to design, reducing the need for heating, cooling and lighting, the requirement for expensive renewable technologies can be designed out and will only be used to meet the most frugal of demands.

Climate change is becoming a greater concern for our clients. To ensure comfort and commercial viability, building designers need to assess the potential impacts of future weather from the outset of a project. It is clear that climate change requires a fundamental change in the way we think about design - from an approach that is based on past experience to one that is based on calculated projections of future climates.

Gale & Snowden has been at the forefront of research into developing integrated design strategies that help to extend the useful life of buildings. By using future probabilistic weather data, buildings can be designed to tolerate the effects of climate change. Enabled by funding from the Technology Board, these research projects have indicated that the same low energy, passive design principles that help to reduce heat losses can be equally successful in providing a robust strategy for mitigating the risks of climate change on a building and reduce the frequency of summertime overheating.

A life cycle cost analysis carried out as part of the same research, showed that if these design strategies are implemented from project conception and combined with regular maintenance cycles, a building can be future-proofed against climate change and its useful life extended, for a minimal uplift in the initial cost.

An interesting scheme for alsecco and Gale & Snowden was at three sites for Exeter City Council as part of the Councils on-going strategy to build more council homes to address fuel poverty in the area. The 14 properties have been built on infill sites making use of areas of land not presently being utilised. Gale & Snowden provided full architectural, mechanical and electrical services, designing the properties to the Passivhaus standard, adopting a fabric-first approach whilst also addressing the issue of fuel poverty and the need to ensure residents’ fuel bills would be kept to a minimum.

alsecco’s  external wall insulation system was specified for the scheme as it eliminates the danger of interstitial condensation and thermal bridging since the insulation is on the outside with the thermal mass of the block work retained on the inside. A Silitect top coat was used to complete the installation and finished in three shades of red on some properties and cream on the others echoing colours found in the local landscape and making for a striking visual appearance of the blocks as a whole.

Passivhaus has to influence every aspect of your design and construction and must be understood and integrated from the outset. With our integrated, coordinated approach we offer a whole building solution working with like-minded system and product providers.

We are keen to dispel the myth that Passivhaus buildings have to look a certain way or are created in a certain style. Our supply chain enables us to source materials, products and systems that you wish to use for the ideal solution for your Passivhaus building.

If you are interested in learning more about our approach to Passivhaus then please contact us to arrange a CPD-style presentation or  to request a brochure Tel 01785 818998 or email passivhaus@alsecco.co.uk.

View The Latest Issue