It is too early to predict with confidence what the long-term impact of Covid-19 will be on the built environment. Illustrating this are the conflicting views on whether or not it will speed up or slow the transition to a low-carbon economy. However, it seems likely that the crisis will accelerate some trends that were already evident. These could have a significant impact on how we are able to meet emerging Net Zero Carbon (NZC) targets for buildings.
Most of us have learnt a great deal about remote working in the last few months. Much has been written about how commuting will reduce. But that reduction, in itself, might not have as significant an impact as first thought. Some estimates suggest that the increased heating in housing may more or less offset the savings from reduced commuting. This is especially true of the UK, which has some of the least thermally efficient housing stock in Europe.
Some estimates suggest that increased heating in housing may offset the savings from reduced commuting”
More positively, the growth of cycling for commuting shows every sign of accelerating even more dramatically, and for a much broader group of participants. The pressure for buildings, as well as the public realm, to reflect this with much better cycling facilities will only continue to increase.
People have also realised just how dramatically air quality in city centres has improved. Regrettably, that improvement will probably fall back as activity increases, but there will be growing pressure on local politicians to ensure future improvements. Ultimately, better external air quality will increase the feasibility of mixed-mode ventilation in city-centre buildings. Even if it remains unviable today, future-proofed buildings will soon need to allow for it.
One facet of remote working that will be largely positive environmentally is cloud computing. The collective realisation that VPN connections and remote desktops are imperfect is accelerating a process that was already happening, albeit tentatively. For low-energy office buildings, it is a very significant development. Up to a quarter of a building’s energy use can be associated with centralised IT, such as on-site server rooms, patch-rooms and their associated cooling.
The UK Green Building Council’s NZC energy performance targets for offices were released in January this year. An important technical note within them, which isn’t yet widely understood, is that the ultimate 2035 ‘Paris Proof’ target already assumes the wholesale uptake of cloud servers. Until recently the question was how to push occupants in that direction quickly enough. That has now changed.
For low-energy office buildings, cloud computing is a very significant development; up to a quarter of a building’s energy use can be associated with IT”
Having servers off-site removes the associated energy use from the Net Zero Carbon targets for buildings. The shift from ‘scope 2’ indirect carbon emissions (arising from the generation of purchased energy) to ‘scope 3’ indirect emissions (occuring elsewhere in the value chain) does need to be acknowledged by tenants, as does the huge environmental impact of the internet generally. Nevertheless, moving servers off-site does seem to make sense. The data aren’t conclusive, but the available studies conclude that the overall carbon impact of cloud computing is about half that of site-based servers – albeit, the choice of provider has an enormous bearing on the actual carbon impact.
Without the shift, it is difficult to see how the 2035 NZC target of 55kWh/m2/year is achievable (down from an average today of 200-250kWh/m2/year). Central IT would take up the entire allowance for tenant loads.
Fewer site-based servers will reduce the operational energy use of office buildings, as well as having an impact on embodied carbon. It will also remove large amounts of dedicated IT cooling plant, with savings in both space and embodied carbon. Declining need for hardwired local connections (when coupled with 5G and power-saving ARM-type chips) might also reduce the need for raised access floors, which can account for as much as 10 per cent of the day-one embodied carbon of a building – similar in magnitude to that of the facade.