Watch our webinar with Schüco, which explores ways of optimising indoor comfort while maintaining environmental performance.

There is a growing body of evidence that demonstrates the importance of lighting, ventilation and good acoustics to our experience of buildings. Indeed, they form key components in the concept of ‘wellbeing’. Yet at the same time, we are urgently concerned about lowering the carbon footprint of our buildings, to help ameliorate the climate crisis. Can these two desires be reconciled? Is it possible to enjoy daylight and fresh air in our buildings without emitting irresponsible quantities of carbon dioxide? This is the issue that the speakers at this webinar addressed. And – spoiler alert – they concluded that yes, we can do both.

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Buildings.

Designed by Zaha Hadid Architects, the MAXXI gallery in Rome achieves a delicate balance between delivering thermal comfort and expressing the connection to the outside (ph: Hufton & Crow)

Buildings.

Speakers from left to right: Shaun D Fitzgerald, Nick Cramp, and Alina White

The most straightforward explanation came from Dr Shaun Fitzgerald, director of the Centre for Climate Repair at Cambridge. He subtitled his talk on Covid and the climate ‘Why improved ventilation is synergistic rather than in opposition to progress in energy efficiency’. He talked about the documentation, by bodies ranging from the World Health Organisation to CIBSE, on the importance of ventilation in preventing Covid. But this did not mean, he said, that ‘we need to blast every space with cold air’. Instead, he said, ‘We need to identify poorly ventilated areas and improve them.’

Sensors in schools will, he said, typically show some areas where high levels of CO2 (the indicator of poor ventilation) constantly peak. This is because windows remain closed for thermal comfort. Instead, he said, these areas need controlled ventilation for use in winter – systems that use heat recovery or heat recycling. As a result, he said, energy use will actually be lower than relying solely on radiators as the system will use the heat generated by people, only topped up by other heating. And in the summer? Just open the windows.

Buildings.

Advanced simulation of the building’s physics and a flexible approach to the exhibition planning lessened the need for interventions controlling light and air at MUMA’s Queens Diamond Jubilee Galleries at Westminster Abbey (ph: Alan Williams)

Nick Cramp, senior partner in the light and air team at Max Fordham, talked about the work that his practice does, righting mistakes of the past. ‘Concern about light damage to exhibits caused many of the great museums to block up all their windows in the late part of the last century,’ he said. He called this decision ‘reactionary, impulsive, and ultimately wasteful. A large part of our work is renovating these institutions and putting the light back.’

Cramp believes in doing as little as possible to buildings and using as little new material as possible to minimise the embodied carbon. The engineer used this approach when creating an exhibition space for the treasures of Westminster Abbey. The Queen’s Diamond Jubilee gallery was a space that was previously unused because of uncontrolled light and air.

Buildings.

Herzog de Meuron’s Blavatnik Building at Tate Modern, London, is an international standard art gallery which is mostly naturally lit and vented (ph: Alex Upton)

Max Fordham ‘processed every ray of bouncing light and the wind pressure for three months,’ said Cramp. As a result, it was able to provide useful material to exhibition planner MUMA. Most of the exhibits are in glass cases to stabilise their environment, with very little change to the building fabric. ‘The existing building stock is adaptable if we want it to be,’ Cramp said.

Similarly, when working on the latest phase of Tate Modern, the engineer argued that most of the exhibits require only broad control. The most demanding areas, those that house temporary exhibitions, occupy only around a quarter of the space. Requiring those conditions everywhere is, therefore, wasteful.

One of the surprises, Cramp said, referring to the Maxxi gallery in Rome, where the practice worked with Zaha Hadid Architects, was that using artificial lighting during the day can actually be more energy efficient than daylight. This is because efficient LEDs can use less energy than would be lost through windows.

Buildings.

Due to complete in 2024, 3 Chamberlain Square is a landmark office building in Birmingham designed by Feilden Clegg Bradley Studios (cgi: by Glenn Howells Architects)

A similar surprise came from Alina White, an associate with FCBS studios, who talked about the practice’s project at Three Chamberlain Square in Birmingham. The overall carbon impact of using double-glazed windows can be less than with triple glazing, she said. Although triple-glazing offers better insulation, this may be more than offset by the additional embodied energy contained in the larger unit – particularly if it also needs a more robust structure to support it.

Analysis by Cundall, which also worked on the project, showed that the overall carbon impact depended on how much the grid was decarbonised in the future – a prediction about which nobody can be certain.

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View showing the new public space between Three Chamberlain Square and the Grade 1 listed Town hall in the Birmingham Paradise development (cgi: Glenn Howells Architects)

Another societal change is the move towards electric car use. White’s design includes opening windows, on the assumption that the lower noise and pollution levels will make people keener to open windows in city centres in future. So on this building, every other window opens to provide natural ventilation to the first 7.5 metres of depth. The windows are placed high on the floors with solid panels below.

These counter-intuitive solutions require the sophisticated modelling that Cramp showed. But this does not mean, he said, that we cannot learn from the past. He showed three types of tents used by nomads. Analysis showed just how well Bedouin and Tuareg tents dealt with light and air, directing the flow and providing shading where it was needed. Those tents were, of course, refined by centuries of trial and error. The tools we have now allow us to make decisions on a host of different buildings – to balance the demand to reduce ambient and embodied energy with creating the best and healthiest places to live and work and relax.