23 Aug 2019
“Good wind microclimate conditions are necessary for creating outstanding public spaces in the City for all”. (City of London Corporation)
Such was the headline of the UK’s first wind microclimate guidelines, published this week by the City of London Corporation (CLC), affecting new development proposals within London’s ever climbing Square Mile.
Strong winds around the base of high-rise structures is a well-documented effect, as is the ‘channelling’ effect of wind being forced through narrow gaps if multiple towers stand close to one another. Now, for the first time, developers will be required to provide a more robust assessment of the impact of new developments over 25m tall, raising the benchmark for acceptable wind conditions in the City and combating the effect of potential wind tunnels on city workers and cyclists.
This year’s New London Architecture London Tall Buildings Survey found that 60 skyscrapers were to be completed in 2019, with an overall pipeline of tall buildings in the capital at 541. Within the Square Mile cluster, another 13 skyscrapers are planned by 2026 with six already under construction and seven having received planning permission from the CLC. Alistair Moss, Chair of the Planning at Transportation Committee at the CLC, acknowledged the need to address the impact of the increasing number of planning applications for tall buildings on microclimate conditions, stating “it is important that the knock-on effects of new developments on wind at street-level are properly considered”. The move has reportedly been supported by many cycling groups.
2026 View from City Hall
Source: GMJ and City of London Corporation
What does this mean for developers and future planning submissions?
The guidelines dictate that developers proposing a tower more than double the height of its surrounding buildings will need to provide both wind tunnel testing and Computational Fluid Dynamics (CFD) assessments. CFD’s should be undertaken by an appointed wind consultant and will test the impacts of a scheme within early design development (i.e. pre-application stage). This can allow proposals to be adapted and necessary solutions to be found early on, preventing costly mistakes further down the line in the determination process of major planning applications.
Developers should take note that proposals for development situated in ‘exposed areas’, such as near the Thames and other sensitive pedestrian areas, transports hubs, hospitals and schools may require more detailed checks. The guidelines encourage early consultation with CLC planning officers, to determine whether their project will be subject to additional requirements.
The CLC also indicate that other factors such as temperature, sunlight, air quality and noise, which also influence our enjoyment of outdoor spaces, may be incorporated into a future edition of the guidelines. Interestingly, this links to the increasing and welcome consideration of pedestrians and cyclists ahead of cars in the City, exemplified by recent publicity surrounding traffic-free-lunchtimes and Sadiq Khan’s car-free day.
Overall, with London’s skyline continuing to head upwards, the new guidelines mark a significant and pioneering step by the CLC. However, other areas of London and ultimately other cities also expanding vertically, will need to follow suit, preparing guidelines or adapting existing policies to address the impacts on microclimate conditions at ground level, supporting the prioritisation of the safety and comfort of pedestrians and cyclists.
Which Way is the Wind Blowing?
Two imminent changes to the development consent order (DCO) regime - the removal of onshore wind developments and the introduction of ‘related’ housing - prompt interesting questions about how the localism agenda is understood in the context of nationally significant infrastructure project (NSIP) proposals. In particular, can housing actually be delivered through the DCO process, while keeping the spirit of localism alive?
The Infrastructure Planning (Onshore Wind Generating Stations) Order 2016 is due to come into force on 1 March 2016. This will effectively change the thresholds in the Planning Act 2008 that dictate whether a wind farm scheme is to be considered as an NSIP or not. Reflecting the Conservative Party’s Manifesto and subsequent promises, and in tandem with a clause in the Energy Bill 2015-16, this will effectively remove onshore wind farms from the DCO consenting regime, and give the power to determine onshore wind schemes, even those above the previous threshold of 50 MW, back to local planning authorities.An Energy Bill factsheet, published this month by the Department of Energy & Climate Change, makes clear that these changes are the realisation of the Government’s manifesto commitment to decentralise decision-taking on onshore wind. It is explicit in stating that the vociferous local opposition often directed at wind farm applications has led the Government to wash its hands of this particular decision-making responsibility. The move is intended, ostensibly at least, to allow local communities to have a greater say in the determination of wind schemes.Framing wind farm development as a local issue however, too sensitive to communities to be handled by the Secretary of State, invites comparisons with a seemingly different approach being taken elsewhere in the UK’s emerging legislative framework on DCOs.
Homes under the…NSIP Regime
The Housing and Planning Bill 2015-16 is now at Committee stage in the House of Lords, complete with draft clause 144 (formally 107) which will allow for ‘related housing development’ to be included in an infrastructure scheme application for a DCO. A DCLG Briefing Note published back in October 2015 sought to iron out some of the ambiguity of this clause; it confirms that up to 500 residential units may be considered by virtue of a geographic proximity or a ‘functional’ link.Whilst the scope for a qualifying scheme will be restricted, introducing any form of housing into the NSIP regime is an exciting prospect for those who see the DCO as a mechanism that is not yet used to its full potential. But the new mechanism does sit a little uneasily with the spirit of the ‘localism agenda’.The Government has gone to great lengths to address housing as a local issue, with need and supply defined and planned for by local planning authorities. Notwithstanding the extensive consultation and LPA inputs that are characteristic of the DCO process, the imminent removal of onshore wind schemes shows that the Government is not oblivious to how the DCO process can be seen as ‘skipping’ the local level.So how will the NSIP regime fare once/if housing elements start to crop up (even if it is limited to ’related housing’), and to what degree will development plan ‘local’ housing policy, and potential community backlash, be allowed to influence consideration of the principle of a DCO application as a whole?
A Point of Principle
While many residential schemes are (eventually) determined by the Secretary of State already, the DCO process is designed to deliver infrastructure development for which there is a pre-determined, national scale need, ordinarily enshrined in a National Policy Statement. It is not designed as a forum to debate the principle of development, something which would be surely inevitable if ’related’ housing elements are considered as part of NSIP DCO applications. Quite how this will work will be interesting to follow, particularly given the degree of community interest generated by housing developments normally.Time will tell how local communities will react if a perception emerges that they, and their local planning departments, are being denied the opportunity to determine applications for certain housing developments, particularly if the residential element is seen as ‘riding the coat-tails’ of an NSIP, through to achieving development consent.
From a delivery perspective, the flexibility to progress much-needed housing in NSIP schemes seems to be ‘a good thing’ - although the vast majority of housing will not quality for the DCO ‘treatment’, and will continue to be determined via conventional planning applications (and appeals). Regardless, removing onshore wind from the DCO regime with one hand, but introducing elements of ’related’ housing with the other, appears to be a contradiction.Any NIMBYist outcry against housing delivered in this way, should it materialise, will pit the resilience of an expanded DCO regime against the traditional interpretation of localism. Localism seems to have won the day with onshore wind…will housing fare better?