n eerie mechanical hum has joined the usual backdrop of tweeting birds and the roar of the North Circular at Wanstead Flats in London. The sound is coming from behind a large wooden fence, recently erected on wide open fields by Epping Forest, where a group of long, white marquees poke up above the tree line. It looks like the makings of a beer festival, but the reality is far more bleak: the hum is not coming from beer taps, but from a generator that will be used to keep a fleet of storage units at 4C for the coming weeks – the temperature required to prevent human corpses from decomposing. Covering an area the size of two football pitches, this new complex is a temporary mortuary, one of many such structures that are being erected at lightning speed across the UK to cope with the rising death toll from the coronavirus pandemic. This East End outpost is conveniently next to the City of London Cemetery and Crematorium, and just three miles from the new NHS Nightingale hospital at the ExCel convention centre – a strategic location for what the Newham mayor Rokhsana Fiaz described in a letter to local residents as “a holding point before a respectful and dignified cremation or burial can take place to send a loved one on their final journey”. It is a storage depot that grieving relatives will, of course, never be allowed to visit. The Wanstead facility is one of almost 200 temporary mortuary complexes being built around the UK and in Ireland in preparation for what the Cabinet Office has described as “the reasonable worst-case scenario”, when tens of thousands of bodies might overwhelm the capacity of existing morgues. There was no plan for such a crisis, so each region is responding according to what facilities and spaces are available. In Devon, refrigerated lorries have been set up on an empty lot close to Torbay hospital. In Milton Keynes, an ice rink has been co-opted for the task, its cooling infrastructure making it well-suited for the job. In Dublin, the Irish Museum of Modern Art (housed in the former Royal Hospital Kilmainham) will return to a clinical purpose, hosting a mortuary on its grounds, while an aircraft hangar at Birmingham airport is being converted into a morgue with capacity for up to 12,000 bodies. From mobile mortuaries to drive-through testing stations and pop-up intensive care wards, the coronavirus outbreak has witnessed one of the largest ever peacetime mobilisations of temporary infrastructure. It is an Olympian effort of scaffolding, marquees, inflatable tents and portable cabins, as existing buildings have been repurposed in a matter of days. With construction having to begin before plans were finalised in many cases, architects, engineers and fabricators are responding at a speed that leaves time for no more than basic essentials. This is emergency architecture at its most elemental. Portakabin, the York-based firm that has been synonymous with prefab buildings for 60 years, has been at the frontline since mid-February, delivering many of the emergency structures. They began by erecting assessment pods and isolation units in hospital car parks, and they are now working on the government’s national programme of mortuaries. “We were contacted by the commercial directorate of the Cabinet Office asking what could we do around ‘storage buildings’,” says company director Robert Snook. “It soon became clear what that meant.” Portakabin has form in refrigerated storage, with previous prefab modules being erected to store everything from exotic orchid bulbs to fine wines. The morgues’ racking and shelving systems, however, were a new challenge. The bulk of the firm’s work to date has been in delivering large amounts of overspill space for hospitals, so wards with lower-risk patients could be relocated to free up more space for those with Covid-19 in the main hospital buildings. Snook says this is all business as usual for a company that is used to rapid response, having delivered an emergency hospital to the Falkland Islands during the war in the 1980s, and built an entire secondary school in nine weeks following the Grenfell Tower fire. “This is all standard stuff for us,” says Snook. “The main challenge has actually been getting our hands on enough FFP3 face masks for our workers to wear in the factory.” While companies such as Portakabin have been supplying standard modular shells as usual, with the factories working full pelt, some situations have required more bespoke solutions. One of the most technically demanding of the temporary structures so far has been the transformation of the ExCel convention centre at the Docklands area in east London into an emergency field hospital, NHS Nightingale, ultimately capable of holding 4,000 patients. The gargantuan exhibition halls have hosted a diverse range of functions in the past, from the Crufts dog show to international arms fairs, but this incarnation has stretched the building’s flexible nature to the limit. Completed in nine days, it has – like every other part of the national response to Covid-19 – been worked out on the fly. The location was settled on in mid-March, after other large sports halls and warehouses were considered. The ventilation system is equipped to handle large numbers of people, the floors are riddled with mechanical service boxes and there is a readily available supply of modular partitions and teams of technicians used to mounting exhibitions overnight. “The strategy was all about using as much of the existing infrastructure as possible,” says James Hepburn of BDP architects, who led on the design team for the project. “It was clear on day one how difficult procurement was going to be, as a lot of factories were shutting down. We used the exhibition partitions with a bit of extra stiffening to create the bedheads, then ran the power, water, drainage and medical gas in a long service run behind, mirroring the bed bays on either side.” Visibility between the bays was key, given that the doctors will each be charged with many more patients than usual. The site became a 24-hour production line, coordinated by army personnel, seeing vinyl floor laid, partitions erected and teams of electricians assembling prefabricated dado trunking to be screwed to the bedheads as soon as they were up. The central boulevard between the conference halls, usually home to networking delegates, has been transformed into a controlled zone where medics don and doff protective clothing, while the waterfront cafes have become their much-needed rest areas. Of course, there is a mortuary, too. “It’s interesting that when the army sets up a camp with a field hospital, one of first things they do is build the mortuary,” says Hepburn. “There’s a psychological element to it – if you’re in a war situation, knowing that that side of it is dealt with is actually quite reassuring.” Learning from their experiences, BDP has produced a “how to” guide, drawn in the clear diagrammatic style of an Ikea furniture-building manual, to help other projects. Similar emergency hospitals are under way in Bristol, Harrogate, Birmingham and Manchester. Despite the rushed intensity of the process, might the whole experience offer some lessons for the future? “If someone asked you to design a hospital like this, you would normally say you need six months and an enormous team of carefully selected individuals, not a group of people thrown together over a weekend,” says Hepburn. “Here, there wasn’t the usual ‘design responsibility matrix’ or any of the admin that bogs everyone down. It was a very liberating, free-form collaborative approach, and it shows what’s possible when everyone really pulls together with a common goal.” “If we ever get back to normal,” he adds, “projects are going to become very frustrating when someone says no.”