The debate about the impact of embedded carbon in existing buildings looks set to continue, following the decision of Westminster City Council to allow the demolition and redevelopment of Marks and Spencer’s flagship Marble Arch store. We are all used to seeing the retention and refurbishment of buildings because they are listed, but with the growing climate emergency it cannot be long before a Council refuses to allow the demolition and redevelopment of a building on the grounds of its carbon impact.
The existing policy system is adapting to the new priorities, although the legal framework does not entirely support this approach. Many Councils have planning policies that support a net zero carbon approach to new development and allow financial contributions towards carbon reduction projects to enable schemes to meet a net zero target. In the case of the M&S store that amounted to a £1.2M carbon offset payment. Increasingly, achieving net zero includes both an assessment of the embodied carbon effects – arising from demolition, basement excavation and construction of the building, together with the lifetime carbon efficiency savings generated by the new building. The case for demolition is therefore increasingly likely to be accompanied by a detailed set of calculations that assess both the embedded carbon impact and the cumulative lifetime saving.
However, if this approach is going to be taken seriously the ease that buildings can be demolished under the current regime would need to be revisited, to stop buildings from being demolished speculatively, ahead of the full implications of doing so being considered. Also, are we going to see it being made a requirement that new buildings must be retained for a minimum period, to ensure that the full lifetime carbon reductions are delivered?
The great divide: redevelopment vs refurbishment