Tuesday 28 January 2020
With more than 20% of carbon dioxide emissions lost through our buildings, the D&PA have taken action to promote an improvement of thermal performance and energy efficiency of buildings by agreeing changes to 'Part L' (Conservation of Fuel and Power) of the Guernsey Building Regulations.
The thermal performance of a building is determined by the individual thermal performances of the various elements of a structure - namely the roof, walls, floors and window/door openings and by the efficiency of the services installed. The orientation of a building can limit heat losses and gains through the glazed elements whilst the quality of the build also has an effect and is measured and controlled under Part L.
Currently the local Building Regulations rely on a set of documents known as the Guernsey Technical Standards (GTS) that if followed, are deemed to satisfy the functional requirements set out in the Regulations. The majority of these documents were produced in 2012 and have not had any technical revisions since this time. It can therefore be considered that local standards relating to the thermal performance of buildings, known as GTS Parts L1 and L2, are now 8 years old.
To improve the energy efficiency of new and existing buildings it is proposed to increase these performance requirements by making amendments to the current documents GTS 'L1 and L2'. This will be achieved by:
- Increasing performance standards in GTS-L1 for existing dwellings, including for new build and extensions, to match current English standards, which are appropriate for Guernsey and its climate;
- Increasing the air leakage standard by halving the permitted leakage volume from 10 to 5m3/(h.m2) at 50Pa and to provide clearer guidance on a testing regime.
- Amending the 'U values' in relation to the renovation of existing thermal elements to make them consistent with revised new construction standards and into line with the current equivalent English standards.
- Mirroring the proposed changes for GTS-L1 with a technical amendment to GTS-L2. This will take account of improved U values, introduce specific guidance on air pressure testing of commercial buildings and specifically reference a compliance route following the calculation methods available in the equivalent UK approved documents.
The GTS guidance will be amended to reflect the improved requirements and once approved by the D&PA they will be brought into effect. The D&PA's timetable is for approval of the GTS documents in March with them coming into force at the end of June 2020. As the Regulations are not retrospective they will not affect home owners unless they are planning on carrying out work on the external envelope of their buildings.
D&PA President, Deputy Dawn Tindall, said:
"I am extremely pleased to announce the D&PA's unanimous agreement to these amendments. Climate change has been recognised as reaching a critical point and in June 2019 the States agreed that Guernsey must urgently address the climate and ecological crisis at both local and international level. Increasingly I have been questioned over why our thermal performance standards lag behind those in the UK so, after due consideration, the D&PA has agreed that now is the appropriate time to amend our Building Regulations.
The measures will be put in place shortly through revisions to Part L ahead of the more fundamental review under the climate change mitigation action plan led by the Committee for the Environment & Infrastructure that is due to be debated by the States by May this year. These changes show that the D&PA are listening and can take action without awaiting the direction of the States - action which is urgent if Guernsey is to play its part in respect of the Climate Emergency."
D&PA Vice-President, Deputy Victoria Oliver, said:
"To improve our energy efficiency we must look to tighten up on the thermal performance requirements whilst at the same time being mindful of the effect this is likely to have on the cost of construction. To simply impose strict new standards could stifle construction investment so therefore we have looked to make the changes proportionate.
We believe that these changes strike the right balance to ensure that appropriately higher levels of thermal performance will be achieved in our new and existing building stock and can be put in place quickly whilst also taking proper account of the likely effects of this on the local construction industry and on building costs."