By Ben Humphries and Wendy Bishop

The recent inaugural UK Passivhaus conference, held at the Barbican over 24 and 25 October 2011, celebrated the growing maturity of the low-energy building design methodology in the UK. It also demonstrated the breadth and depth of experience already amassed in a relatively short period of time in the UK, spiced up with presentations (and delegates) from further afield.

In times of austerity, the costs of designing and building to the Passivhaus standard are never far from people’s minds, and several presentations focused on this, providing very different experiences. Jonathan Hines presented Architype’s two recently completed Passivhaus schools, built for no extra cost (to pre James Review cost-plans) by Thomas Vale and reported that their new joint venture were expecting to achieve £1800/sqm for their third Passivhaus school together; Roland Matzig made the case for at least 30% additional fees for the extra work involved by the architect acting as a Passivhaus designer; whilst Sebsatian MorenVacca reported from Belgium, where all new buildings will be built to the standard within four years, that the construction costs for a Passivhaus building are 10% less, and the design time is also reduced.  John Lefever of Hastoe Housing Association reported that the cost of delivering the Wimbish Passivhaus scheme of 14 houses to be 12% over a level 4 Code for Sustianable Homes dwelling, although he expected this to come down to 6% on their next project.

The cost theme was further explored in terms of lifecycle energy costs, with Berthold Kauffmann of the Passivhaus Institute urging us to promote Passivhaus where the developer is also responsible for the running costs, for example on PFI projects. The payback for the additional cost of achieving Passivhaus over a Building Regs compliant design might be relatively short. Matthew Wrate of Couch Perry and Wilkes had calculated that the energy savings expected at Interserve's new office would generate a saving of £20,000 per annum and payback would be achieved in only seven years. John Lefever explained that to afford the additional cost of Passivhaus at Wimbish would mean marginally higher rents than other properties the same size, however, tenants would appreciate significantly greater savings, on their energy bill, and therefore would be better off. Clearly, with rising fuel prices, the marketing potential for registered social landlords to move to the Passivhaus standard is huge.

The big problem it seems is that no one is pushing at senior level. There were complaints that the current government just isn't interested and that housing minister, Grant Schapps doesn't even know what Passivhaus is. However, Lynne Sullivan of sustainableBYdesign, member of the Government's Green Construction Board and chair of the Part L and F working parties of the Building Regulations Advisory Committee noted that she was fighting hard to keep it on the agenda, and some headway was being made in getting the standard recognised as a bona fide alternative to the SAP/SBEM methodology.

Roland Matzig described the Passivhaus movement as a "calm revolution" - a more fitting description than the “cult of Passivhaus” sometimes bandied around, although Berthold Kaufmann's reporting of the research mapping heating and cooling loads in different climates hinted at Passivhaus' own creation myth: when overlaid, some Passivhaus 'paradises' are revealed where heating and cooling needs are perfectly balanced: these notably include Ethiopia, the birthplace of homo sapiens.

Ben Humphries is Associate Director at Architype and Wendy Bishop is an Associate and Certified Passivhaus Designer, also at Architype