City of Westminster’s new ‘retrofit first’ policy

The City of Westminster has recently  launched a partial review of their adopted City Plan 2019-2040^[1]  which introduces a new policy that prioritises retrofitting over new construction. 

Policy 43 – ‘Retrofit First’ aims to support the city’s goal of net-zero by 2040. Envision has reviewed the draft policy, including the supporting Topic Paper ‘Retrofit first and reducing embodied carbon’ ^[2] which supports the consultation, and draws conclusions on this new policy and its implication on development within Westminster. 

“We will not reach net zero without a significant shift in how we view development.

That is why we are introducing one of the nation’s first retrofit policies, promoting sustainable growth by encouraging commercial and residential buildings to be refurbished to the latest standards rather than demolished and replaced with new ones. The policy supports the great work the real estate industry has done to understand how to repurpose buildings to be eco-friendly and attractive to investors, office-workers and people looking for a new home.”

Quote from Cllr Geoff Barraclough, Cabinet Member for Planning & Economic Development

Key Points of the Retrofit First Policy

• Prioritising Retrofitting over Demolition:

Policy 43 requires developers to thoroughly explore retrofitting options before considering demolition. This aims to reduce the environmental impact that would otherwise occur from new developments, by conserving resources and lowering whole life carbon emissions. 

The Policy requires applicants to prepare a mandatory ‘Retrofit Plan’ which must accompany the Sustainable Design Statement for all applications which create new floorspace and/or proposals which involve extensive works to retrofit existing buildings. The retrofit plan should summarise how the retrofit policy has been complied with, including the justification of the following policy points: 

1. The proposed development will deliver public benefits which could not be delivered through a suitably comparable retrofit option; and
2. The whole-lifetime carbon of a new building would be less or similar to a suitably comparable retrofit option; or
3. The proposed development has bespoke operational requirements which could not be provided through the repurposing, adaptation and/or extension of the existing building(s); or
4. It is demonstrated that a retrofitting option is not possible or achievable due to structural constraints, demonstrated through an independently verified structural engineers report.

• Setting Embodied Carbon Targets:

The policy itself prioritises retrofit but still has requirements for new developments where retrofit isn’t possible (and this has been thoroughly justified). As such, a mandatory whole life-cycle carbon assessment along with embodied carbon targets have been introduced for new developments involving total substantial demolition of a building which has more than a single storey. This follows the GLA’s approach of undertaking a Whole Life-cycle Carbon Assessment (WLCA), however the topic paper ^[2] that supports the consultation on this policy, highlighted some of the weaknesses with the GLA’s embodied carbon targets, specifically when it comes to retrofits. 

The topic paper highlights that the average embodied carbon of new build in Westminster is around 700 kgCO₂e/m², which is significantly less than the London Plan Guidance (LPG) benchmarks of 900 kgCO₂e/m² and is nearing the LPG aspirational target of 600 kgCO₂e/m². It also calls out that these targets may not actually align with the pathway to net-zero by 2040 – as is Westminster’s target. 

The paper provides recommendations to set more ambitious embodied carbon targets, which align with the council’s carbon reduction pathway identified by the Tyndall Centre in 2023. The actual targets that have been included in the Policy have instead opted to align with the LETI banding, which are widely recognised benchmarks within the industry. These targets are currently only proposed for upfront carbon, which covers emissions up to practical completion of the project. Depending on project size and typology, the Policy sets an absolute minimum rating of “B” (non-residential & residential below 18m) or “D” (residential above 18m) with “A” or “C” respectively being encouraged as targets. 

Unfortunately these targets do not seem to be ambitious enough to align with the Net-Zero by 2030 pathway, as identified within the topic paper, but are at least more ambitious than the LPG benchmarks. 

• Encouraging Recycling and Reuse:

Where demolition is unavoidable, the policy emphasises that maximising the recycling and reuse of materials to minimise environmental impact. This supports broader goals of reducing waste and promoting a circular economy. Policy 43 includes a requirement for applicants to submit a Circular Economy Statement including a pre-redevelopment audit and pre-demolition audit, which demonstrates how materials will be reused and repurposed. This aligns the City of Westminster’s plan further with the GLA, however this policy could be enhanced further by establishing a reuse target for a specified percentage of demolition waste. 

Based on our experience, setting a target of approximately 10% for direct reuse of demolition materials (either on-site or off-site) is a practical starting point. This target could be gradually increased over time and would help boost the availability of materials in the second-hand market, which would further promote a circular economy.

• Balancing Sustainability with Heritage Preservation:

Westminster’s rich architectural heritage is taken into account, with the policy supporting the retrofitting of historic buildings. This includes integrating modern energy-efficient technologies like heat pumps, insulation, and solar panels while preserving the historical and architectural integrity of these structures.

Conclusion

Overall, the City of Westminster’s new “Retrofit First” policy represents a step forward in the current guidance, and further aligns with their commitment to sustainable development and net-zero by 2040.  Although there are areas for improvement, such as establishing specific reuse targets for demolition waste and more ambitious embodied carbon targets, the  policy is a significant step forward for sustainable development in Westminster.

Envision provide expert advice in the life cycle assessment of buildings, including whole life carbon and circularity assessments. We are able to support developments within the City of Westminster by providing ‘Retrofit Plans’ alongside pre redevelopment audits and Circular Economy Statements, to support alignment with the emerging policy. 

ENDs

[1] https://westminster.moderngov.co.uk/documents/s59268/Appendix%201.pdf

[2] https://www.westminster.gov.uk/media/document/retrofit-first-topic-paper