Ahead of the herd: Norman Foster redesigns the elephant house at a Denmark zoo

Norman Foster, the world's most celebrated hi-tech architect – the Sultan of Seamlessness, so to speak – has just completed an elephant house at Copenhagen Zoo that is not just low-tech but, to an almost shocking degree, earthy in its materiality. If this building had been designed by masters of architectural texture and surface such as Herzog and de Meuron, or Peter Zumthor, that quality would have been a given. The fact that Foster + Partners created this tough and strangely pre-eroded domain is a bolt from the blue. In its way, the elephant house may be as seminal for the practice as the black glass amoeba in Ipswich, known as the Willis Faber building, was in 1974.

Foster's team sought to deliver an architectural paradigm-shift in a genre that is utterly foreign to them. This, after all, is the ultimate high-performance practice: Beijing's mega airport designed in detail in less than four months, a vast array of solar cells in a 6sq km zero-carbon development in Abu Dhabi, and a general hoovering up of gilt-edged corporate and foreign government commissions to such an extent that any design radicalism is increasingly overshadowed by more trivial sugar-rush factoids: the City suits that are now partly guiding the practice, Foster's pink corduroy suits, or Building Design magazine's recent coverage of the "controversial" relationship between the architect's position in the House of Lords and his reported status as a tax exile.

How refreshingly surreal, then, to juxtapose the practice's "brand" architecture with issues such as the drainage of copious amounts of pachydermic urine through sand, and the need to screen from public view the sometimes violent pre-sexual behaviour of bull elephants in must. Imagine what damage these creatures, weighing the equivalent of two Bentleys (or roughly 67 modernist architects) and with 15-ton ramming impact might do if released in the veld of the City and were suddenly alarmed by, say, Foster's Swiss Re building.

This levity is not without point. Foster can certainly design for the masters of the corporate universe, but how did his team address animal behaviour?

Foster's elephant house is remarkable, not least in being genetically linked to similar test-case zoo buildings designed for London Zoo by two legendary architects – the first, a great early modernist, the second, a brilliant polemicist whose anti-architectural stance continues to influence today's most influential architects. In 1934, the Tecton practice, led by Berthold Lubetkin, designed and delivered the Penguin Pool. It was a triumph of architectural form over behavioural needs, and created a mise en scène suitable only for a film entitled "Triumph of the Bill", which might have been made by Hitler's favourite film-maker, Leni Riefenstahl. In the 1960s, Cedric Price's equally polemical aviary at London Zoo was a cat's cradle of angular netting; Lubetkin's response to the natural world was didactic, Price's iconoclastic; and the penguins and birds were left to make the best of the results of evolved human creativity.

Foster's designers have deployed low-tech solutions in the elephant house. They are embedded in a deliberately roughly crafted architecture for the elephants, and smoother spaces and finishes for the public areas. There is no question that the elephants' internal and external environments are excellent; unusually, they are constantly on the move indoors, for example. Result: better muscle tone, and improved skin and heart condition.

The processional qualities of the visitors' path through the building, and out into the open, where they are within feet of the creatures in a relatively unrestricted way, is equally notable. And it is significant that the two trademark asymmetric glass domes that bathe the separate bulls' and mother-and-calf stables in light seem of only fleeting architectural interest. The real architectural action is elsewhere.

It started with research at Vienna and Chester zoos, and the subsequent concept drawings of Narinder Sagoo, one of Foster's key architectural conceptualisers. "It was such a task!" he says. "The brief was an inch thick, and all about the animals. We stayed here for several 24-hour cycles and watched what went on to see how the existing elephant house functioned. And then I made a 24-hour storyboard to confirm what we saw to the keepers. We had to get the story right. We felt that the building should have a narrative, so that you would be able to see how elephants inhabited space, and nature. We also realised that we could revolutionise these zoo enclosures."

Armstrong Yakubu, Foster's design group leader, puts it more impressionistically: "It's about light, sand and air for the elephants; and we had to find a way for humans to slip through their spaces." Spaces whose architecture is not about obvious enclosure, but about disclosures and connections that dealt with changes of scale, ergonomics and sheer animal power; and in a way that made sense to the keepers during the design development phase. Foster himself identified the possibility of designing the elephant house as a building of complete accessibility and no signage; and that possibility arose from Sagoo's original narrative drawings. There are no steps at any point, and there is only one way through the building – in a downward spiral that leads to the path through the outer landscape towards the exit-point.

The architectural qualities of the elephant house are founded on a number of progressive "moments". The approach to the building meanders on high ground past the original Edwardian elephant house, with views to the animals' landscaped outdoor domain spread out below. The elephant house itself is partially buried in sloping ground to maximise thermal insulation, and as soon as you enter the building, you are looking down into the huge volume of the mother-and-calf stable; descending through the building, there are exhibition and lecture spaces, and glimpses of the bulls' stable.

The polished concrete of the floor and walls changes from a clean beige to a deliberately dirtier yellow; elephant smells gradually increase, and then you're passing through a double-height colonnade, barely divided from the animals at ground level among the branch-scattered sandhills which are remodelled every day to keep them in wandering, exploratory mode under the dappled shadows created by computer-generated leaf patterns etched into the glass of the domes.

The building's material qualities, controlled by project architect John Jennings, have ensured the general success of its physical and visual thresholds. As Yakubu puts it: "The concrete was going to be the most expensive material. So we said, let's make it the most beautiful thing in the project." The demarcations of smooth and rough-cast reinforced concrete – and apparently abstract arrays of massively strong posts, whose spacings only just separate elephant from human – have created a place of unexpectedly relaxed co-existence, almost untroubled by overt refinement, apart from a beautifully made, spiralling ipe hardwood handrail and perfect alignments for the ceiling lighting tracks, and formwork tie-rod positions.

But these are merely incidents. It is the tough, crafted physicality of this building, and the landscape elements, that really strike home. It has taken the future well-being of 10 Indian elephants to generate a Foster building that radiates an overtly human touch, and a reminder that great architecture must feel made by hands and minds, rather than designed by insouciantly skillful mouse-click. The Sultan of Seamlessness seems to have discovered the surprising virtues of thick, rough architectural hides.