We welcome the proposed policy direction but feel the policy needs to be strengthened at a number of points as explained below. As a broader point: we welcome the ambition shown in applying more rigorous
standards than existing national schemes (such as BREEAM), but have concerns about how this will be
delivered in practice. We look forward to further information on how the Planning Authority, Building Control and other departments will work together to ensure effective delivery of these policies. We are pleased to hear that the Planning Authority currently intends that the policy will apply to minor developments (to be confirmed at later policy stages), and will consider applying the policy to temporary buildings on a case-by case basis.
● Embodied carbon. The recognition of embodied carbon is positive but does not go far enough. The definition of a Net Zero Carbon building set out in the Evidence Base does not include its embodied carbon: this is a very serious omission which undermines all claims made about the sustainability of new development.
● Retrofit first. A report by the US National Trust for Historic Preservation [1] concluded that “reusing an existing building and upgrading it to be as efficient as possible is almost always the best choice regardless of building type and climate”. Before any new build is undertaken, consideration must be given to reuse of existing buildings. The policy should require a whole-life carbon assessment whenever demolition of an existing building is proposed. This would enable a carbon pay-back time to be calculated: how many years will it take for the carbon savings achieved in a more efficient building to offset the carbon losses incurred in demolition and construction? (see also under Climate Change ‘general comments’ for further discussion about retrofit)
● Use of sustainable materials. Where new build is necessary, the choice of materials must consider their embodied carbon and broader sustainability credentials, as well as their insulating properties. Reuse and recycling of materials should be favoured. The use of timber from sustainably managed (ideally UK) woodland should be promoted. Lime mortar should be used instead of cement wherever possible. Finally, buildings should be designed for longevity.
● Offsetting. We welcome the conditions set out under ‘Part D’ (page 146) that limit the use of offsetting. It is important that offsetting is genuinely a last resort and is not used by developers to avoid meeting net zero requirements on-site. The carbon accounting for any offsetting schemes applied must be rigorous and transparent.
[1] https://living-future.org/wp-content/uploads/2016/11/The Greenest Building.pdf