Canal plus.

The removal of the last printing press in Paris gave an old publishing firm space to expand and create a new image.

Until 1993, the Bayard Presse building in Rue Bayard contained the last printing works in Paris, and on their removal, Bayard was left with 2000 square metres of empty shambles on the ground floor. The entrance to the building, begun in the '30s and incorporating several different structures, was a modest one on the Rue Bayard. Employing about 1000 people, the company decided to take the opportunity to add a new civilised dimension to staff facilities and to create an entrance more in keeping with the image of a prosperous modern publishing house. Patrick and Daniel Rubin of the architectural practice Atelier Canal, won the competition to remodel the ground floor and were appointed the architects.

Canal's scheme includes a new entrance hall, library and archive store, various offices and meeting rooms. In effect, it exhibits the same coherence and invention that was remarkable in an earlier scheme by the practice, the transformation of part of a redundant car park in the centre of Paris into airy civilised offices for Liberation, the French national daily (AR May 1988). In that case, as in this, the architects have made sense of apparently intractable and amorphous space.

In the Rue Bayard, the ground floor was stripped of extraneous clutter down to the basic structure - the brick shell and handsome brick and stone columns. The plan describes part of a rectangle, stepped down along one of the long sides towards the rear of the building so that the broadest part faces on to the street.

Here in the centre and set back from the street is a new entrance hall and the beginning of an internal street which articulates the main longitudinal axis at the basis of the architects' spatial organisation.

Space has been layered back from the street along the axis, with the public, communal facilities, like the post room and library, being placed around the entrance hall and giving way to more introverted accommodation: the research department and trade union offices, and further on to neutral spaces, the meeting and conference rooms at the rear.

Circulation circumscribes the plan. The internal street takes you up to an informal meeting point, an open space beneath a big illuminated disc, and cafeteria. Beyond it, a long corridor running past a row of meeting rooms continues the axial thrust to the edge of the building. Corridors running at right angles give access to a long side gallery and stairs to upper floors.

As in its design of the Liberation offices, Canal has kept the conversion as simple as possible, exploiting the positive characteristics of the place - the sheer expanse of space and sturdy structure - and enhancing them by means of light, colour and material. A vertical dimension has been added by restoring old rooflights and adding another (the building has very few windows), with daylight cleverly diffused through the interior. In the reception hall, the architects have opened up the ceiling to admit daylight and views of the offices of La Croix magazine at first floor level. This not only illuminates the entrance but at once states the company's business. Other lights long obscured and excavated shed daylight into the research department, the meeting point and cafeteria. At the rear, a glazed gallery diffuses light into the adjoining meeting rooms.

Throughout the interior, finishes and materials have been carefully chosen to express a lyrical play of oppositions between the existing and the new, formal and informal, and so on. Such tensions, together with the architects' use of colour to animate surface and geometry, is continually lively. Large expanses of ceiling have been given depth by the simple device of colouring the original surfaces dark blue to obscure the ducts, and then partly masking them with suspended ceilings that project light within a recessed dark frame.

The interior street has been made luminous by glass walls screened by louvres and enlivened by colour. Silk-screened walls in the reception area soften the light. In the meeting rooms, which are divided by movable screens, neutrality is matched and given character by fine detailing. Handsome wooden panelling and brightly-coloured furniture, plaster ceilings and carpets give them a formality that is seductive - and splendid when opened to their full extent.