I sat high in the North Stand for one of Arsenal’s last games — a patrician dismissal of Everton — at the old Highbury stadium. The vastly bigger and blingier new Emirates ground was about to open nearby. What was going to happen to the old place, I asked as we queued for burgers and beer. They’re going to convert it into housing, they said; the pitch is going to become a new London square. Oh sure, I thought. Like that’s ever going to work.

Now here I am, in a new flat high up in a block where the North Stand used to be, looking across the old Highbury pitch. The last Gunners game was played here in May 2006, and the development is officially launched this Thursday. Instead of the almost extraterrestrial lushness of the football surface (Arsenal’s groundsman was legendary), I’m looking at what appear to be allotments. At second glance, however, they turn out to be a series of different gardens — some wild, some manicured, some high, some low — arranged in a grid pattern with paths and places to sit. It’s all rather Alice Through the Looking Glass, a chessboard landscape. For all that, it is indeed a new London square: two acres of open space, surrounded by flats. But it still feels like a traditional football ground.

This ultimate conversion job cost more than £150m to build, and it contains 724 apartments. A bit bigger than the poky developer norm, they are somewhat upmarket, with all the usual stuff in them, and there are at least 60 left to buy, at prices ranging from £250,000 for a one-bed flat to £1.5m for a three-bed penthouse. More than 60, in fact, depending on how many of the precrunch sales fall through and go back onto the market. I saw plenty of evidence of people living there and moving in. I also saw quite a few empty flats. Property valuations — having fallen by some 10% as the recession took hold — have now recovered and are close to where they were. Arsenal FC is not officially lowering its asking prices, banking on the strength of its name and the uniqueness of the project. In comparison, two-and three-bedroom homes elsewhere in Highbury, north London, go for between £500,000 and £850,000, depending on location.

Just how do you turn a historic stadium into homes? It would have been easy to flatten the whole lot and build rabbit hutches, keeping only the listed art-deco facade of the main East Stand (its companion West Stand, hidden behind terraced housing, was unlisted, and the newer stands at the north and south “clock” ends were nothing special). But neither Arsenal FC nor its architects, Allies and Morrison, wanted that. The club borrowed heavily to fund a high-end development, rather than hiving it off. And the chosen architects were no developer hacks, but the same people who restored the beloved Festival Hall on London’s South Bank. The sacred pitch itself was given to the top-notch landscaper Christopher Bradley-Hole, winner of many a Chelsea medal of the non-footballing kind.

Doing things properly is in the club tradition. It started out in 1886, in Woolwich Arsenal — hence the name — and moved here in 1913. The ground was a simple playing field at first, shoehorned into the working-class terraced streets. The great East and West Stands were built in the 1930s under Arsenal’s famous manager, Herbert Chapman — there’s a bronze Epstein bust of him in the foyer, not the kind of memorial afforded to many footie bosses of the time. For their day, they were the most lavish ever built. So while at the north and south ends the developers just demolished the stands and built new blocks to about the same height, on the east and west sides it was a matter of actually converting Chapman’s steel, brick and concrete stands into housing.

This required some sleight of hand. It wasn’t possible to fit flats around the steeply raked tiers of seating, so the stands were gutted behind their facades and all the key historic bits — such as the “sunburst” art-deco steel-framed glazing at the ends, and the architectural mouldings to the upper seating tiers — were taken away for restoration. Then the flats were built, the historic bits went back on, bad later alterations to the main facade were removed and new metal roofs were built to match the look of the original — but with two layers of living space inside the roof.

It’s been cunningly done. “At 96 metres long by 18 metres wide, the stands were coincidentally about the right dimensions for residential blocks,” says Chris Bearman, the architect. Standard flats are four metres wide (some are double-width). What you would imagine as the main visual drawback — that you have vertical glass walls on the fronts of the previously open-fronted stands — in fact works well. Bearman explains how they modelled these facades with industrial-sized steel girders so as to avoid them looking too flat and reflective.

Each stand has seven levels. Below the eaves on the fourth floor, you get some triplexes, two levels of two-storey duplexes and one level of single-floor flats. Above the eaves, there are two further storeys in the roof, including penthouses. The flats looking inwards sell at a premium, but the flats that look out have great views on the upper levels; the more ordinary new blocks at the north and south ends are arranged around smaller courtyards.

It’s a shame, in a way, that the flats don’t preserve some of the tough, painted-concrete character of the old stands. But with heating and hot water provided centrally, and solar panels up on those huge roofs, fuel bills will be low, and you get underground parking and a gym with pool beneath the (private) gardens. There’s a crèche, too, and the Arsenal Tube station is nearby. Even if the football links mean nothing to you, it makes sense as a place to live in London. Truth to tell, half of the buyers are investors — one bought a block of 140 homes at the north end — and only one-third owner-occupiers. Still, the memorabilia in some of the windows proves that some real fans have bought here.

Buildings often change their uses, but seldom as radically as this. It feels just slightly surreal — those Through the Looking Glass gardens add to the vague sense of strangeness. That is good. Also good: absolutely nowhere in those new gardens on what was once the pitch did I see a sign saying “No ball games”. Well, they wouldn’t dare, would they?

Highbury Square officially opens on Thursday. For more information, call 0845 262 6000 or visit highburysquare.com

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