Can Passivhaus design become the 'norm'?Published on: 19th February 2015
With sustainability a hot topic for the election, Will Price, MCIAT Chartered Architectual Technologist, assess whether Passivhaus housing design will become the norm.
If you work in the UK housebuilding industry you’ll be very familiar with green technologies and the legislation aimed at achieving sustainable house building.
In 2006, the government announced that all new homes would be ‘zero carbon’ from 2016 and subsequently introduced the Code for Sustainable Homes (CSH) - the cornerstone for sustainability in all new-build homes. This code was introduced as a mechanism to achieve the European Performance of Building Directive (EPBD) which states that all new public buildings must be ‘nearly’ carbon neutral by 2018 and all other buildings by 2020.
The government announced in 2014 that this code may be wound down and consolidated into the Building Regulations through the housing standards review. However, there’s no doubt that over the last few years it has had a galvanising effect on the housing industry and spurred innovation in green technologies, enabling developers to build more energy efficient homes
The pressure to cut carbon emissions will only grow in the future and the legislation will become more stringent. Therefore, it will become increasingly vital for architects and builders to adhere to environmental building practices. The government has launched a consultation on a new voluntary sustainability standard for new homes with the ultimate aim of improving quality and choice for the consumer and driving innovation across the housing supply chain. The burden is set to fall on landlords too, as from April 2016, tenants will have the right to request consent for improvements to make their homes more energy efficient, which landlords can’t unreasonably refuse.
With all of these increasing pressures to adhere to environmental standards, it’s perhaps not surprising that many UK architects and builders are adopting the so-called ‘fabric first’ approach to energy efficiency and adopting the Passivhaus design principles as a template for new homes.
Passivhaus is the global leader of eco-friendly construction practices, which originated in Germany in the 1990s. This design approach minimises a building’s demand for heating and cooling through methods such as high levels of insulation, an airtight building fabric and mechanical ventilation systems. According to the Passivhaus Trust, Passivhaus buildings achieve a 75 per cent reduction in space heating requirements compared to standard practice for UK new builds. It therefore provides a robust method for helping the housebuilding industry achieve the 80 per cent carbon reduction target by 2050 that was set as a legislative target for the UK government in 2008.
Whilst current standards look to offset carbon though complex and expensive green technologies Passivhaus removes the requirement for technology at all. This principal sees highly efficient building envelopes combined with mechanisms that harness the sun’s energy, removing the requirement for expensive green technologies. With this in mind, an additional question to ponder is if Passivhaus is adopted, could that spell the end of the currently booming green technology industry?
In Germany, where Passivhaus was born, 20,000 homes adhere to this design standard compared with just 250 in the UK. According to the report Lessons from Germany’s Passivhaus experience, there are many reasons why the uptake in the UK has so far been slow. Many UK homes are built speculatively, whereas in Germany, an increasing number of houses are self-built using competitively-priced low energy kits. Secondly, the report points to the German population having a stronger interest in the environment than UK residents, so the government is spurred to take more action. Lastly, there’s the financial aspect to consider, as the German government provides assistance for people wanting to build a home to the Passivhaus principles whereas the report points to a ‘lack of such financial support here in the UK.
This being said, certain UK cities, such as Bristol and Exeter, have been driving forward Passivhaus design in new developments. In Bristol, a new Passivhaus development of nine apartments and 17 houses is due to be completed this year. It’s very timely as all eyes are on Bristol this year as it is the first UK city to be crowned European Green Capital. Bristol 2015 is an opportunity for the city to showcase its achievements in sustainability, with the ultimate aim of becoming a role model worldwide – an initiative that Sanderson Weatherall is supporting.
Meanwhile, Exeter City Council is currently in the process of building 20 new Passivhaus homes at three different sites in the city. With sustainability a hot topic on the agenda for the May 2015 general election, it’s perhaps not surprising that Exeter’s Labour Council wants to position itself as being proactive on the issue of on sustainability. However, in order for Passivhaus design to become ‘the norm’ UK-wide, it can’t just be about politics. There needs to be fundamental changes to energy regulations, or indeed, we need to see the devolution of energy controls to a local government level.
Furthermore, for other councils to follow Bristol and Exeter’s example, there must be a strong business case for adopting these standards. At the UK Passivhaus Conference in 2014, Exeter City Council said that because this standard provides an improved living environment for tenants, landlords can theoretically charge higher rents. There is also evidence that the increased asset value of these types of homes is being formally recognised with the Hastoe Housing Association reporting it had received a valuation for some homes, that added £10,000 per unit to the value, purely on the strength of the standard they will meet.
Whether Passivhaus will become ‘the norm’ UK-wide is difficult to say. However, with sustainability and renewable energy widely tipped to be one of the key talking points in the 2015 general election, perhaps we could see this happen sooner than we think.