The M&S Oxford Street inquiry was a clash of world views

The M&S Inquiry was really a clash between two opposing world views. On the one hand you have the M&S approach which is essentially a 20^th Century mindset, in that new development is seen as fundamentally a good thing and that demolishing buildings that are less than 50 years old, or still viable at 90, is ok.

To achieve this end the M&S team have gone out of their way to denigrate three perfectly reusable and surprisingly inter-connected buildings to try and prove this point. The new build would, they say, offer improved storey heights, better public realm, better internal organisation and would have a high BREEAM rating demonstrating its sustainability credentials and of course better operational energy performance.

On the other hand, you have the SAVE approach, which is responsive, not just to BREEAM and the other site issues, but specifically to the climate emergency. This approach recognises that, with the government’s legally binding commitments of 2019 and 2021, to respectively achieve net zero by 2050, and 78% reductions by 2035, everything has changed.

“…you can’t get to net zero by flipping a green switch, we need to rewire our entire economies”

To quote Mark Carney when he was governor of the Bank of England, “you can’t get to net zero by flipping a green switch, we need to rewire our entire economies”. What Mr Carney has recognised is that the ‘net zero’ requirement is transformational and fundamental. It is not something that can be solved with a fancy BREEAM rating or by demolishing reusable assets.

We are at the beginning of period of massive change every bit as extensive as the UK’s change during the 18^th and 19^th centuries from an agrarian economy to an industrial one, except that now we have less than 30 years to affect a similar level of change. Those that recognise this will succeed, those that don’t will, like Kodak or Blockbuster (remember them?), fail.

If you compare the two approaches, the M&S new build proposal and the SAVE deep retrofit, several things become apparent. Many of the claims for the new build scheme such as public realm improvements, better servicing access, and better internal reorganisation can, to a very large extent, be replicated in a deep retrofit.

…according to Arup’s own assessment, the existing structures are easily capable of taking as many as three additional storeys

The new square in Granville Place, the resolution of the unpleasant overhangs along Orchard Street, access at ground level from Oxford Street to the new square, plus the relocated service bay can in my view be resolved with an imaginative and extensive retrofit.

Operational energy performance could also, with the intelligent use of insulation, double glazing and all new services, be very close to that of a new build. The existing facades are, apart from the glazing, robust and after a deep retrofit, would be capable of a very long life.

Further, according to Arup’s own assessment, the existing structures are easily capable of taking as many as three additional storeys. The basic structures of the three buildings are simple, regular concrete or steel frames.

Digging out basements (particularly in central London) and building deep concrete structures is a very high carbon activity

The removal of the existing perimeter cores would not impact the structural integrity and would open the buildings up to light, regularize the floor plates and improve efficiency. A new central core, matching the layout of the new build, could be introduced using existing escalator voids.

This approach would of course result in carbon emissions expenditure, but these would be significantly less both in upfront, construction emissions and in in-use emissions both embodied and operational than a new build. These buildings would be set up for the future.

In my estimation a deep retrofit with additional storeys could achieve some 50,000m² against the M&S scheme which achieves just over 60,000m². The M&S proposal would however be at a significantly higher kgCO2e/m² cost and also a significantly higher total tCO2e cost. And of course it involves total demolition with associated waste and transport as opposed to selective, localised and relatively minor core removals.

This means that around 2050 the new build will be facing a major retrofit of its own

Ironically certain features of the new build scheme are very counterproductive in carbon terms. The new build requires three new levels of basement as opposed to reusing the existing one. Digging out basements (particularly in central London) and building deep concrete structures is a very high carbon activity.

The new build’s proposed storey heights (3.9m) are, I would argue, excessive and could be more tightly designed by reducing them to both reduce embodied carbon from construction and the operational energy use from cooling the extra volume (plus reduce capital and running costs). The cladding systems are predominantly aluminium and glass, and according to Arup’s whole life carbon assessment have a life expectancy of no more than 35 years.

The new build proposal has a claimed life of 120 years. However according to the Arup carbon assessment most components only have a life expectancy of 35 years or less. This means that around 2050 the new build will be facing a major retrofit of its own.

The government’s net zero commitments in 2019 and 2021 had no apparent impact on the design of the building

The M&S planning submission documents showed that the existing buildings have simple structures that are capable of not just reuse but several additional storeys, and enabling significant internal reorganisation. The documents also show that any idea of a deep retrofit was abandoned in 2018 (as confirmed at the inquiry) with no serious work on examining deep retrofit since then.

The government’s net zero commitments in 2019 and 2021 had no apparent impact on the design of the building. This is why in my view the M&S scheme is fundamentally a 20^th Century rather than a more subtle and imaginative 21^st Century proposal.

Many of the large developers, such as British Land and Landsec are, in response to both the market and the climate crisis, focussing much more on the retrofit/hybrid approach. M&S have not responded to changing circumstances in the same way.

Why have none of the parties involved sought to deliver the level of change referred to by Mark Carney and mandated by legislation?

I would note that I am not against new construction, and certainly not against the deconstruction (and recycling) of redundant buildings, but for this site we are not in that position as these buildings are clearly an opportunity rather than the claimed liability.

It is interesting that all parties involved in the new build scheme have impressive sustainability credentials, M&S has Plan A which specifically mentions their concerns about construction waste, and of course Arup are considered leaders in this field. Both Westminster City Council and the GLA have policies prioritising retrofit, yet seem unable to change direction in response to the urgent need to deal with the climate crisis.Why have none of the parties involved sought to deliver the level of change referred to by Mark Carney and mandated by legislation?

I am wondering what it is that is encouraging M&S to continue to pursue this course of action, which seems so at odds with their Plan A. Could the fact that their current share price is approximately a quarter of what it was in 2015, and that the completed new build might be worth roughly half their current market capitalisation have anything to do with it?

…we can no longer afford to pay lip service to climate issues

Who knows? But we can no longer afford to pay lip service to climate issues. We need to act positively and decisively in response to climate change. We need to get on with “rewiring our entire economies”.

Given that the built environment sector is responsible for some 40% of global emissions we have a lot to do. Large new schemes that require the demolition of reusable carbon assets is not the way to move to a net zero and circular economy. M&S’s new build proposal therefore is fundamentally retrogressive and will be seen as such for years to come.