SWINGS AND ROUNDABOUTS

Revolving doors
Codes and standards might tell you how to design a revolving door, but they won’t stop users plumping for the swing option instead. Careful specification and construction can go some way to help

Words Jan-Carlos Kucharek

There’s a queue developing outside the new, elegant, glazed revolving doors of Oxford’s Ashmolean Museum, although not necessarily for the right reasons. Not that Stuart Cade, project architect for Rick Mather Architects, is worried. The firm’s proposal to radically transform the former main entrance, consisting of the original doors that had been sawn in two halfway up, only to enter CR Cockerell’s blustery lobby, wasn’t only to enhance environmental protection for the museum’s precious artefacts, but also to make something aesthetically intelligible and beautiful of the entrance itself.

What replaces it is a highly minimal solution – a 4m high, 2.3m wide fully glazed, automatic Record revolving door with two side-hung, DDA-compliant doors either side, giving views from the street, like some baroque stage set, directly into the depths of the museum. Since it opened, however, the droves of museum visitors have been putting the doors through their paces. It’s been noted that people are hesitating and stopping, or rushing to go through and so activating the door brake, and impeding visitor flows. Having designed the doors using the relevant standard, namely BS7036, Cade’s job now is to conduct post-occupancy studies of the door, and decide on the fine-tuning, like revolve speed, to ensure that operation is optimised. He’s found that while codes and standards might tell you how to design a revolving door, they can’t predict the human interactions and psychologies incumbent in its use.

The main reason for specifying revolving doors has always been to prevent draughts and conserve energy, but since they have been deemed ‘inaccessible’ under the Disability Discrimination Act (DDA), and with BS5588 and Approved Document B both demanding expedient and unimpeded egress from a building in the case of an emergency, the need for additional doors comes with the territory. Revolving doors are most often specified alongside swing doors, usually positioned in close proximity to one another. But this has implications in terms of which doors people use and for what reason, and it ultimately affects the energy performance of the building itself. Those with physical or mental impairment and mothers with prams need automatic swing doors, but it’s about ensuring the able-bodied don’t opt to use them, as each time they are opened the ability of the building to conserve energy is compromised. Due regard for energy efficiency is desirable, but as a spokesperson for the National Building Specification attests: ‘Building owners are always worried about being sued, so the environment just has to wait’ – a comment unofficially affirming the primacy of the DDA and Part M over Part L regulations.

Least resistance
‘People will always take the route of least resistance,’ says Paul Watson, chairman of the Automatic Doors Suppliers Association. ‘In the industry we say the best doors are the ones that people notice least. That’s why we’ve been moving towards revolving doors with only two wings, giving a larger compartment to pass through, and which, once open, gives a clear view through to the other side for the user.’

While increasing the likelihood that they will be used by the less able-bodied, this kind of ‘no nuisance’ design is critical to their being effectively used by everyone, he says. New doors are tipping their hats to DDA compliance by incorporating handicapped buttons that slow down the door’s movement, and even the requirements of Approved Document B are beginning to be addressed with door leaves that ‘failsafe’ outwards in the event of an emergency. But Watson thinks specifiers have to accept the limitations inherent in the door’s principle, adding: ‘If you have a lot of people trying to enter in some kind of free-for-all, it won’t cope. There’s no magic solution – it’s simply about optimising door positions and speeds.’ 

As far as energy efficiency is concerned, Watson sees the new breed of revolving and sliding doors answering that, ‘with dual motion sensors that identify a person moving toward the door, through it, and away from it, minimising the time a door is in motion or open’. Manufacturers are looking not only at energy savings on site but also reducing the carbon footprint during manufacturing and supply.

For Ian Durbin, partner at service engineer Hoare Lea, reconciling building performance with the need for a fully DDA accessible entrance area gets more polarised the more stringent Part L regulations become. ‘With increasing insulation of the building fabric, air leakage in these areas really begins to matter. There’s growing pressure to ensure entrances are as sealed as possible – the amount of energy squandered can be huge.’

Durbin believes attention to the specification and construction of doors is fundamental, citing a recent example on a business park in Oxford which, despite a coherent energy-efficient design strategy, suffered post-completion temperature problems. ‘It turned out there was a 2.5cm gap between the frame and rotating panels and brushes of the door, that had a major effect on the internal temperature of the reception – the designed thermal benefits were totally lost.’ The new Part L Display Energy Certificates and Energy Performance Certificates will put an end to such sloppiness in detailing, he says.

So with air tightness assured, we return to the big ‘X Factor’ of the whole issue – the human aspect. For architects to create a preference for revolving over neighbouring swing doors, the trick is in generating a psychological ‘Hobson’s choice’ for users. A Massachusetts Institute of Technology report, Modifying Habits Towards Sustainability: A Study of Revolving Door Usage on the MIT Campus, is one of the few that analyses the psychological and habitual components of door use, and set itself the task of discovering ‘an effective means of getting people to use the revolving over the swing door’. Aiming to influence ‘almost unconscious door use decisions’, the survey concluded revolving doors remain ‘stressful’, and ‘cramped or dangerous’, and that swing doors are quicker and require less effort. While only 42% of respondents said that signage reminding them of the environmental point of the door would influence their decision to use it, 61% said they would use it if the person ahead of them had, suggesting ease of passage through a revolving door is fundamental to its efficacy in an overall building energy strategy.

Usable and sustainable
Of course, it remains for the construction industry to decide how revolving doors can be technically modified to become truly sustainable by being realistically useable for all members of the public, whatever their needs; but until then it seems that existing two-part ‘revolve and swing’ approaches to entrance design are here to stay. This is probably no bad thing if one considers the needs of likes of Sir Terry Pratchett, author of the Discworld novels and chronic Alzheimer’s disease sufferer, who in his televised David Dimbleby lecture on the Right to Die last month, even managed to squeeze in his views on the ‘quintessential’ challenge of the revolving door.

‘I have to approach very carefully. It’s glass, it’s full of reflections, and it’s both coming towards me and going away at the same time,’ he said with characteristic perspicacity. ‘It’s an odd moment when my brain needs to sort things out.’