Land is a valuable commodity in London, with demand exceeding supply. Building horizontally is no longer an option. To meet the required densities in housing and make the most efficient use of land, it is necessary to build tall.
The London Plan, the framework for the next 20 to 25 years to accommodate a population of 10.8 million, makes a compelling argument for tall buildings based on the idea of a compact city. According to the plan, we must create places of higher density in appropriate locations to get more out of limited land, encourage a mix of land uses and co-locate different uses to provide communities with a wide range of services and amenities.
In May 2023, New London Architecture (NLA)1 published its 10th annual report, ‘London Tall Buildings Survey 2023: Sustainable Skylines’. This influential report provides the latest data and analysis on the contribution of tall buildings to a more compact and sustainable London.
While previous surveys focused on the pipeline of tall buildings, the spotlight this year is on sustainability and how towers can deliver lower carbon emissions, be more sustainable and support high-quality environments for occupants. So, how can towers become sustainable?
According to Ender Ozkan, Vice President Europe, Rowan Williams Davies & Irwin2, a broad-spectrum approach is needed. “It will require some really innovative approaches and innovative materials – building skins that adapt to the climate – with natural ventilation and energy capture from the sun. And also, long life and recyclable components, which makes embodied carbon no longer such an issue.”
Heating and cooling tall buildings
Alongside improvements to the building fabric and the use of renewable energy systems, such as solar photovoltaic, high-efficiency HVAC solutions are key in reducing carbon emissions and supporting occupant wellbeing.
Carrier’s solution for the landmark building 22 Bishopsgate is an excellent example of how modern, high-performance systems can contribute to more sustainable high-rise buildings and help transform cities.
Carrier supplied four AquaEdge 19XRV centrifugal chillers for 22 Bishopsgate, each delivering 4MW of cooling with efficiency levels as high as 6.8 European Efficiency Rating (EER). Equipped with Greenspeed Intelligence variable speed drives, the chillers constantly match cooling output to the building’s heat load, optimising comfort, reducing energy consumption and minimising impact on the environment.
London has ambitious carbon reduction targets to achieve net zero by 2030. The route map includes a 40% reduction in total heat demand from buildings and the installation of 2.2 million heat pumps over the next seven years. It also requires that 460,000 buildings be connected to district heat networks by 2030.
To meet these aggressive targets, more district heating networks are needed where recycled heat is harnessed to warm homes and businesses. The Citigen district heating energy centre project is an example of Carrier’s proven HVAC solutions to reduce carbon emissions and lower energy costs. Citigen is groundbreaking in its use of ultra-low global warming potential HFO refrigerant and parallel harnessing of energy from groundwater and waste heat from the power generation unit. Additionally, Carrier’s heat pump solution is recovering heat generated from data centres, which is used by more than 20 district heating grids across the Nordics and Europe, helping to reduce carbon emissions.