24 Nov 2009, 6:24 PM
The minimum standard for the energy efficiency of zero carbon homes has been announced by Housing Minister, John Healey. The figures equate to a 25% reduction on the currently permitted CO2 emissions for a gas heated home. Healey asked the Zero Carbon Hub to assemble a special Task Group following his Policy Statement on zero carbon homes earlier in the summer. Members of the Task Group published and presented their report to the Minister following an intensive period of consideration and consultation.
Presented as a new Fabric Energy Efficiency Standard, the Task Group’s recommendations aimed to deliver a high yet practical energy performance level for all new homes. The Standard focuses on the fabric of the home, to secure long lasting benefit for home owners and occupiers, and to ensure that energy efficiency plays a proportionate part in the ultimate delivery of zero carbon homes.
Announcing the recommendations, John Healey said that the new standards signalled “real momentum to change and radically re-think how we design our towns and homes for the future.”
Neil Jefferson, Chief Executive, Zero Carbon Hub, said “The Fabric Energy Efficiency Standard is a critically important step towards the delivery of zero carbon homes from 2016. The Group has agreed upon a performance level that it has judged to be stretching and appropriate for mass scale production in the UK.”
The Zero Carbon Hub was able to convene a Task Group of senior industry experts to critically evaluate existing knowledge and develop proposals. These proposals were then evaluated through a wider consultation process involving 450 people to assess their acceptability within major interest groups. The consultation process strongly endorsed the core recommendations of the Task Group and provided valuable insights which informed the final recommendations.
The Task Group recommendation focused on the building fabric, essentially covering the thermal performance of walls, floors, roofs, windows and doors.
A range of energy metrics were considered by the Task Group. Energy demand (measured in kWh/m2/year) was selected and two levels of performance proposed.
39 kWh/m2/year is the target for apartments, and mid terrace homes, 46 kWh/m2/year is the target for end terrace, semi detached and detached homes.
To provide a reference this level of energy demand equates to an approximate 20-25% reduction in CO2 emissions compared with current regulations for a gas heated home.
At these levels the construction specifications of the mid and end of terrace are similar, with the detached home (because of its high proportion of external wall) requiring a slightly higher specification. As this is a performance based specification, in all cases a range of solutions supported by guidance will be available to designers and builders.
The Minimum Fabric Energy Efficiency Standard will assist designers on the journey towards meeting the ‘Carbon Compliance’ requirement of 70%.
The Task Group’s work gives a priority to understanding the capital cost uplift associated with increased levels of energy efficiency. For the build specifications required to meet the standard, the capital cost increase over a house built to today’s standards would be between 3% and 9%* with the detached home at the higher end of the scale. However, this is incorporated in the cost of achieving overall Carbon Compliance.
After gauging the reaction of the industry to a range of different timing options, the Task Group is recommending that the Standard is fully implemented from 2016, with an intermediate step in 2013.
Crucially the industry has called for a very early announcement, in 2010, on the finalisation of the Standard.
The Task Group has given detailed consideration to how the Fabric Energy Efficiency Standard relates to wider aspects of sustainability and energy policy objectives, such as energy security, broader environmental concerns and minimising future risk of fuel poverty. During consultation, technical, social and financial risks associated with an increase in energy efficiency were evaluated and these contributed to the selection of the final performance Standard put forward.
Stewart Baseley, Executive Chairman of the Home Builders Federation, said “The Zero Carbon Hub has done a good job in a short time in considering what a future energy efficiency standard for new homes might look like. Its recommendations are broadly pragmatic: the technology required for delivery already largely exists. The industry will, however, need to assess the merits of specific delivery options and keep a close eye on the cost implications as part of the wider issue of ensuring the zero carbon policy is affordable.”
Lynne Sullivan RIBA, Member of RIBA Sustainable Futures and CLG’s Building Regulations Advisory Committee, said “In the context of the UK Carbon Compliance definition, this standard demands an advanced level of energy efficiency on a par with leading European standards, whilst safeguarding contextual sensitivity to prevailing technologies and cladding options. Architects and fellow consultants are keen to embrace higher standards and play our part in ensuring the energy savings they represent will be actually delivered in use.”
Meanwhile, The UK Green Building Council called for a 50% cut in carbon emissions from the built environment by 2020. Speaking at the UKGBC’s annual conference, taking place in London, chief executive Paul King called on the construction industry to recognise its own role in reducing carbon emissions.
“We drastically need to cut emissions from all sectors, but the built environment offers the best cost-effective opportunity to do that. We have the technology and the know-how in the industry, but we haven’t managed to mainstream these yet.”