The first speaker, Stuart Baillie, head of planning at Knight Frank, sponsor and co-author of the NLA Tall Buildings Survey 2022, summarised its findings. A record number of permissions were granted (98), but there was a continuing decline in applications submitted (72). Starts on site are the lowest since 2014, excluding the 2020 pandemic year. Stuart speculated on whether the steep rise in construction costs, coupled with more stringent tests in the 2021 London Plan, may mark a long-term tall buildings slow-down. Meanwhile the action has shifted to Outer London, with clusters of towers appearing on key suburban transport nodes, and from flats for sale towards flats to rent, with 35% of completed residential towers purpose-built for rent. 

Stuart described the formidable regulatory, technical and financial challenges affecting all residential development in London but which becomes more acute with height: the politics of planning, including affordable housing; building safety; embodied and operational carbon; construction cost height thresholds. 

June Barnes, former chief executive of East Thames Housing Group, and I introduced a research project, which we will be launching in September, along with the LSE, Allies and Morrison and Levitt Bernstein. Our focus is on the long-term sustainability of tall residential buildings, and we provided two examples of our draft findings to date. 

June spoke about the cost to leaseholders of management and maintenance through service charges and sinking funds. Components generally have a 25-year life, and the cost of replacing M&E kit and cladding at height is high. Apart from those who retain entire blocks for rent, developers have no incentive to plan for durability and ease of maintenance and no obligation to warn leaseholders of their liabilities. There is little consumer protection, and legal remedies are costly and complex. The forthcoming ‘commonhold’ tenure will give leaseholders more control, but the challenge of life-time costs remains: the UK norm of fragmented ownership seems poorly suited to tall buildings.

I spoke about the amount of public and shared open space delivered by tall building developments. The issue applies to all development, but tall buildings can create local population spikes of thousands of new residents and workers overburdening existing parks. Most of us value open space, there is plenty or research about its importance to wellbeing, and we have all sorts of planning policies to protect and enhance it – when asked, only one audience member asserted that open space is a waste of space. And yet there is widely differing provision in super-dense developments– from generous (Queen Elizabeth Park) to minimal (North Acton and many stand-alone towers occupying their entire site footprint). Other developments provide small but perfectly formed and curated open spaces – these are valuable, but can they substitute for ‘loose fit’ parks where people can kick a ball, walk a dog and experience nature? Also, there is some correlation between boroughs with the tallest buildings having the least open space and highest levels of deprivation. This raises questions about how much we really value open space and whether delivering more homes justifies a reduction in access to it. In any event, we need better evidence on which to base such decisions: please help by completing our survey https://blogs.lse.ac.uk/lselondon/tall-residential-buildings-project/

Three speakers then shared their experience of designing and delivering tall residential buildings. Roger Black, creative director at Ballymore, began by talking, not about buildings – ‘’empty vessels for human interaction’’ - but about urban loneliness, and the effort his organisation puts into creating social opportunity for their residents, through the design of shared spaces and the ‘‘choreographing’’ of community events, such as the summer fete at Royal Wharf. Roger then turned to more concrete issues, using Ballymore’s City Island to illustrate the merits of off-site construction – ‘’innovation driven by market inefficiency’’. With each tower requiring only 12 site operatives to assemble the factory-built modules, he emphasised the benefit of minimising disturbance to those occupying the completed blocks.

Simon Bayliss, Managing Partner at HTA Design, expanded on the off-site construction theme by presenting his practice’s portfolio of build-to-rent projects with Vision Modular. The latest is Ten Degrees in Croydon, where 546 apartments were assembled from 1400 modules around a slipform concrete core in just nine months. At 44 storeys it is the world’s tallest modular residential tower. Simon outlined some impressive benefits when compared with traditional construction: 55% faster construction period; 40% reduction in CO2 emissions; 80% reduction in vehicle movements; 80% less construction waste.

Simon Bird of LOM Architecture and Design spoke about their co-housing scheme in Hounslow, next to the new civic centre. At 15-storeys it’s tall for its context, although short of the NLA’s threshold. Simon talked about the planning challenge of inserting a large building into such a prominent site, and how the project delivers a new public open space at street level as well as shared roof terraces for residents (who do not get private balconies). Co-living is a stepping-stone for young graduates towards their own self-contained home. It’s a great way to meet a niche housing need – which potentially extends to older single people – but is regarded with some suspicion by planning authorities, fearing micro-flats by stealth. 

There were lively panel discussions, which also involved Daniella Davila Aquije from the GLA and insurance broker David Isherwood. Topics included: inconsistency and confusion in fire safety exclusion clauses in professional indemnity insurance; disagreement around just how safe or unsafe are London’s apartment buildings; how to address climate change. One interesting nugget was that overheating is a significant cause of turnover in rental flats.

I will leave you with this: 88,000 high-rise homes in London’s current pipeline sounds impressive. But if you look at actual completions over the ten years of the NLA survey they average around 2,600 a year, which is 5% of London’s current annual housing target. There may be good reasons for building tall, but is it an essential response to the capital’s housing needs?