The second meeting of the NLA Expert Panel on Tall Buildings picked up on two of the pivotal themes identified in the initial panel meeting, namely; the perception of tall buildings in London and the environmental sustainability of tall buildings.
1.On the perception aspect, it appears that people are generally positive towards tall buildings in London particularly for commercial buildings and to a lesser extent for residential towers.
Other global cities seem to have better acceptance of tall buildings, particularly when it comes to living, which could due to cultural differences. Perceptions of superior space standards and better quality of space in other cities may also be a factor, with London thought as lagging behind.
Perception is divided into those that live and work in tall buildings and those that ‘look on’ and live nearby. There is a slight ‘us and them’ problem. Tall buildings are either seen as places for people to live in poor conditions, or for the very affluent to look down from.
Other perception issues identified are:
· Tall buildings are often seen as new and alien to London, even if this is not the case anymore
· They contribute poorly to the public realm and local streets
· They can create poor environmental issues associated with wind and shading
· Adding density disproportionally drains local amenities such as schools and doctors surgeries
· Fire safety concerns for living and working in tall buildings following Grenfell
Tall buildings need to be designed flexibly for the unknown and unpredictable events, with Covid a good case in point.
It was agreed that a smaller group would look further at some of the issues raised and consider whether to conduct a public survey on attitudes.
2. The panel moved on to discuss the environmental sustainability of tall buildings
All building types must reduce operational energy demand by at least 75 per cent and embodied carbon by a similar factor before off-setting.
Tall buildings face similar challenges to other building typologies in meeting carbon targets by 2030. However exacerbated by additional energy demands from lifting and pumping during construction and in-use. Challenge lies in additional structural requirements on embodied carbon.
How are tall buildings a sustainable building form?
· Play a role in helping cities reach governmental targets for densification.
· Could help reduce urban sprawl and carbon associated with commuting.
· Long design life should allow for refurbishment and re-use.
· Carbon sequestration great potential for tall buildings – longer life means a stronger case that timber is genuinely sequestered.
What does this mean for the design of tall buildings?
· All electric towers and using low carbon heating- i.e. heat pumps, or connections to district heat networks.
· Increasing consideration of timber, opening vents, consideration of healthy living and wellness.
· Prioritising retrofit and using low carbon healthy materials- responsibly and ethically sourced.
· Taller buildings have smaller roof areas which challenge renewables but PVs integrated into façades are increasingly an option.
What do we need to do better:
· Address the often negative reaction to tall buildings as being “gas guzzlers.”
· Define the energy /carbon targets better for tall buildings. The RIBA targets are for ‘non domestic’ buildings.
· Need better data and tools to assess embodied energy of materials and products from cradle to grave.
· Need better chain of custody and more extensive EPD (environmental product declaration) data.
It was agreed that a smaller group would look at some of these issues in further detail.