Our proposals for an affordable Passivhaus were created initially in response to a call for solutions by the BRE in 2011. We took up the challenge because we think that construction standards in the UK will require a significant move towards Passivhaus principles in 2013 and 2016 and constructors who are serious about addressing this should be familiarising themselves with Passivhaus now. We also feel that there are myths surrounding Passivhaus within the industry, especially on costs to build and these need to be disproved.
We are involved in projects ranging from a single new home to 5,500 new homes where we have the opportunity to influence the type of construction adopted. It is our aim to suggest Passivhaus to our clients whenever we can. We are proud that the UK construction standards have improved so much and in such a relatively short time since 2007 when the Code for Sustainable Homes was introduced, however we feel that the momentum has slipped recently and that Passivhaus has the chance to inject new vigour into the construction sector and when widely adopted will put the UK back into a leading position.
Our approach to this project has been informed by our joint experiences in Passivhaus construction and draws on lessons learned and best practice, as a result we have managed to design the houses to achieve a very low specific primary energy demand of 90kWh/m2/per year without renewables, the target being 120 kWh/m2/year. Whilst we are aware that renewables are desirable and would assist in energy capture they cost thousands of pounds and we feel that the target build cost should be as low as possible to start with, they can always be added back in later if desired.
We have also chosen a form of construction that is common in northern mainland Europe, fired clay monolithic blocks with a wood fibreboard external wall insulation and render finish. This was chosen because we believe that buildings should be designed to have much longer life spans than 60 years and be adaptable in their use over time, allowing buildings to change from houses to flats to shops to offices. This form of construction is durable, thermally massive, infinitely recyclable, easy to dispose of and very quick to build with. It also has a much lower embodied energy footprint compared with conventional masonary cavity walls. The construction typologies are all vapour open and very robust with excellent acoustic properties.
Axis Design + Brooks Devlin – 2011
