How green is your skyscraper? Why the most sustainable buildings might be low-rise

Well, this one's pretty green. The Empire State Building, in its St Patrick's Day gladrags. Image: Getty.

The fact a controversial cornucopia of towers is coming London’s way is well known – and some who support this development claim that towers are “greener” than low-rise living.

But are they? My new research project at UCL’s Energy Institute (conducted in association with Create Streets) will try to discover if high-rise buildings are more energy-intensive than equivalent low-rise buildings. At present the evidence is uncertain, but there are suggestive hints. We intend to test them.

Many variables can affect tall buildings’ energy use – and only some of them relate to height. There is the use of energy in lifts. There is the use, or not, of air conditioning. There can be important differences due to building construction, especially between glass curtain walls and solid walls, since rates of heat loss are greater through the glass. Finally, there will be effects related to the local environments of buildings – such as orientation, overshadowing and exposure to sun and wind.

There is some evidence on the relationship between height and energy use. A 2003 study of 20 comparable Hong Kong office towers found that, as high increased, there was a steady increase in energy too. Each additional storey added on average 3 kilowatt hours per M2.

But the use per M2 for lighting and – perhaps surprisingly – lifts did not increase with height. The biggest increase was in the energy used for heating, ventilating and air conditioning. The Hong Kong climate is hot and steamy: we would expect heavy loads for air conditioning. But these were greater, per unit of floor area, the taller the building.

The energy element of the English Housing Survey provides evidence of the relationship between energy use and height in tall residential buildings. A preliminary analysis of data on both low- and high-rise purpose-built flats shows that the latter use on average more than twice the amount of electricity annually (although the sample is small).

That said, there have been studies that have shown little or no difference in energy use with height. Aedas Architects analysed theoretical designs for tall office buildings, using simulation models, and found only small increases in energy intensity with height.

Researchers at the LSE carried out a study of energy use for heating in residential buildings of many different types. They found that energy use decreased with height. However, they too were working with simulations. Furthermore, their sample only included buildings up to 11 storeys.


Why might we expect energy use to increase with height? The obvious characteristic of tall buildings is that they stick up above their neighbours: they are exposed to higher winds. Data from the Chartered Institution of Building Services Engineers shows that wind speeds do indeed rise with height

And higher winds can contribute to increased energy consumption in several ways. They remove heat from the surfaces of buildings. They increase drafts, meaning that the air inside requires more heating or cooling. And they can increase the rates of conduction of heat through the building’s envelope, especially through glazing. Tall buildings tend also to be more exposed to the heat of the sun, and are less likely than low-rise to be overshadowed by trees or other buildings. This can lead to increased energy requirements for cooling in summer.

It seems at least possible that such effects are insufficiently represented in the simulation models used to estimate energy consumption during the design of tall buildings. This could lead to underestimates of predicted energy consumption in practice.

It’s sometimes suggested that a concentration of tall buildings around public transport hubs can help shift travellers from cars to buses or trains, and so reduce energy consumption in transport. This may be true. However, it is an argument for higher densities rather than skyscrapers, as such.

Some researchers have looked at the potential for “green” retrofitting of existing tall buildings. Valuable as this work is, it seems possible that most, if not all, of the conservation measures and renewable technologies employed in “green” or low-energy skyscrapers could equally be applied – perhaps with greater effectiveness – in low-rise buildings. One could also imagine that the potential for adaptation and refurbishment would be greater in low buildings than in tall ones. Might the most sustainable skyscraper not be a skyscraper at all?

Philip Steadman is professor of urban and built form studies at University College London. This article is adapted from an essay he wrote for Create Streets.

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As EU funding is lost, “levelling up” needs investment, not just rhetoric

Oh, well. Image: Getty.

Regional inequality was the foundation of Boris Johnson’s election victory and has since become one of the main focuses of his government. However, the enthusiasm of ministers championing the “levelling up” agenda rings hollow when compared with their inertia in preparing a UK replacement for European structural funding. 

Local government, already bearing the brunt of severe funding cuts, relies on European funding to support projects that boost growth in struggling local economies and help people build skills and find secure work. Now that the UK has withdrawn its EU membership, councils’ concerns over how EU funds will be replaced from 2021 are becoming more pronounced.

Johnson’s government has committed to create a domestic structural funding programme, the UK Shared Prosperity Fund (UKSPF), to replace the European Structural and Investment Fund (ESIF). However, other than pledging that UKSPF will “reduce inequalities between communities”, it has offered few details on how funds will be allocated. A public consultation on UKSPF promised by May’s government in 2018 has yet to materialise.

The government’s continued silence on UKSPF is generating a growing sense of unease among councils, especially after the failure of successive governments to prioritise investment in regional development. Indeed, inequalities within the UK have been allowed to grow so much that the UK’s poorest region by EU standards (West Wales & the Valleys) has a GDP of 68 per cent of the average EU GDP, while the UK’s richest region (Inner London) has a GDP of 614 per cent of the EU average – an intra-national disparity that is unique in Europe. If the UK had remained a member of the EU, its number of ‘less developed’ regions in need of most structural funding support would have increased from two to five in 2021-27: South Yorkshire, Tees Valley & Durham and Lincolnshire joining Cornwall & Isles of Scilly and West Wales & the Valley. Ministers have not given guarantees that any region, whether ‘less developed’ or otherwise, will obtain the same amount of funding under UKSPF to which they would have been entitled under ESIF.


The government is reportedly contemplating changing the Treasury’s fiscal rules so public spending favours programmes that reduce regional inequalities as well as provide value for money, but this alone will not rebalance the economy. A shared prosperity fund like UKSPF has the potential to be the master key that unlocks inclusive growth throughout the country, particularly if it involves less bureaucracy than ESIF and aligns funding more effectively with the priorities of local people. 

In NLGN’s Community Commissioning report, we recommended that this funding should be devolved to communities directly to decide local priorities for the investment. By enabling community ownership of design and administration, the UK government would create an innovative domestic structural funding scheme that promotes inclusion in its process as well as its outcomes.

NLGN’s latest report, Cultivating Local Inclusive Growth: In Practice, highlights the range of policy levers and resources that councils can use to promote inclusive growth in their area. It demonstrates that, through collaboration with communities and cross-sector partners, councils are already doing sterling work to enhance economic and social inclusion. Their efforts could be further enhanced with a fund that learns lessons from ESIF’s successes and flaws: a UKSPF that is easier to access, designed and delivered by local communities, properly funded, and specifically targeted at promoting social and economic inclusion in regions that need it most. “Getting Brexit done” was meant to free up the government’s time to focus once more on pressing domestic priorities. “Getting inclusive growth done” should be at the top of any new to-do list.

Charlotte Morgan is senior researcher at the New Local Government Network.