Architecture: A logical solution to the labyrinth: Peter Dormer looks at an inspired renovation of the Barbican Centre, complete with gilded muses

THE BARBICAN Arts Centre in the City of London is a mournful place. Yet two million visitors a year go there to enjoy a diet of Art, despite the orange and brown gloom, and in spite of having to trudge up and down stairs to meaningless spaces. At last, however, the centre is being renovated - with light and logic.

The Barbican Estate, home to the Arts Centre, houses 5,000 of London's middle class. The heroic concrete architecture is settling down nicely, softened by grass, shrubberies and several acres of water populated with fat ducks and vulgar carp. The opening of the Arts Centre in 1982 made the estate more habitable by animating it with music and chatter.

At present, the Arts Centre's main entrance in Silk Street is dour and glowering. It has a heavy concrete eyebrow and a strip of windows that look like the bridge of HMS Belfast. Moreover, it jumbles people on foot with people in cars. Consequently, a key element in the pounds 9.7m refurbishment is the overhaul and pedestrianisation of the main entrance with a new reception area and artists' entrance.

Theo Crosby, the architect handling the renovation, has not approached his task as a jokey, Post-Modern lark nor as an angel avenging the excesses of Brutalism. He respects Chamberlin, Powell and Bon's strong architecture. Yet, unquestionably, alterations are needed. Under the new scheme the visitor arriving at the Silk Street entrance will enter under a glazed canopy and statues of the nine Greek muses. These have been sculpted in clay by Bernard Sindall, cast in fibreglass and gilded in gold leaf. The gilding will glow prettily against the dark concrete.

The muses are an obvious symbol for an arts centre: Mr Crosby did not want to enter into the pointless Post-Modern game of trying to invent his own 'meaningful' sculpture. Abstract art would not work because the building and the estate are after all, one giant formal abstraction; it would be like adding water to water.

Mr Sindall, a Prix de Rome winner in 1950, is a modern figurative sculptor with much traditional knowledge. Each sculpture has a rhythm that connects it to its partner, so that the nine muses work together like letters making up a word.

The work of another sculptor, Mathew Spender, will be used elsewhere in the Barbican. One of Mr Spender's sculptures, also gilded, but 20ft long, much larger than Mr Sindall's work, will welcome visitors who enter from across the Barbican lake.

Inside, small bronze figures adorning new lamps will direct visitors to the theatres and concert hall, and on the internal doors there will be push-plates decorated with figures and landscapes. This decoration will contribute to the sense of place.

But sculpture alone will not prevent people getting lost. Nor, says Mr Crosby, will the disorientated be helped by the addition of yet more suspended signs. Instead, he will replace these with floor-mounted directions and simple maps. The individual floors are to be renumbered and each will be given a name, such as Stalls Floor, Library Floor and so forth. Visitors have been psychologically wrongfooted by the fact that they enter the Arts Centre at Floor Five. This will now be called the Ground Floor, which is what most of us suspected it was all along.

The erection of a steel and glass bridge will take visitors direct from the Silk Street entrance to the main service lifts and stairs. This will do away with the disorientating experience of entering the building only to be plunged down a staircase to the lower floors when really you wanted to go up.

Feeling lost, as distinct from being lost, is not helped by the Barbican Centre's curiously muddy lighting: there are lots of lamps, but in between the pools of light there are areas of brown fug. Improvements to the lighting will get rid of this effect. Light is also the theme for the one major piece of abstract decoration in the plan, a pointillist mural designed by Polly Hope. In pointillism, instead of mixing secondary colours on the palette, they are set down as intermingled but individual dots or dabs of primary colour on the canvas or wall. Viewed from a certain distance the colours mix in the observer's eye and the resultant colours are, it is alleged, brighter.

All-in-all, the building should be prettier and easier to use. The Barbican has its defects, but a development so big and ingenious can only be completed years after its initial construction. Great buildings and great estates evolve, and it is to Mr Crosby's credit that he is capitalising on the work of earlier generations rather than mocking, subverting or dynamiting it.

(Photographs omitted)