5Plus’s layout at Trafford Borough Council’s offices opts for elegant restraint while letting the bombastic town hall do all the talking, writes Felix Mara. Photography by Mark Waugh
It’s cheaper to keep her,’ warns the old Mac Rice song about the perils of divorce. And you might take this as the message of the AJ’s last two technical studies, which both focused on office retrofits. But John Robertson Architects’ 199 Bishopsgate (AJ 04.07.13) was on a site with no realistic alternative to adaptation and Stiff+Trevillion’s 10-4 Pentonville Road (AJ 11.07.13), also spec offices, is a Derwent project and therefore hand-picked for a retrofit strategy. Trafford Borough Council’s 1983 offices in Stretford on the other hand, which were handed over to the wrecking crew, making way for replacement facilities designed by 5Plus Architects, opened in March.
‘They were dark, with low ceilings and sealed windows and generally horrible to be in,’ says 5Plus director Paul Norbury. ‘The top floor, added later, was the worst: cold in winter and overheated in summer.’
The town hall next door, however, had been listed and therefore survives as an anachronistic 1933 brick heap, retrofitted by 5Plus along with the new offices. ‘We started with a £3 million repair deficit, so the new building had to be low-cost,’ explains Norbury. ‘We didn’t want an inflexible, weird and wonderful form.’ Flexibility, simplicity and low cost was the core strategy. The new offices had to be future-proofed against changes in working procedures and potentially able to be rented to non-council occupants and subdivided, conceivably even retrofitted as a hotel or flats.
5Plus started by simplifying the levels of the new building, lining them up and linking them with those in the town hall, creating generous 3.3m floor-to-ceiling heights. A golden rule of flexible, marketable office design is to avoid changes in level at all costs. Improvements to the landscaping give people the impression they are entering the ground floor on grade. The bunker in the basement of the 1983 offices was retained as storage and also foundations for their replacement. Once crushed, their frame was also used to form a pile mat.
Another golden rule of flexible office design is to create tidy, rectangular floor plates. 5Plus’s diagram involved a double-height street forming a continuous circulation zone along the south side of the new building. This was intended to feed into three fingers, forming an E-shaped configuration, with courtyards between, and 5Plus envisioned diminishing noise levels toward their extremities. The next decision was to convert the ‘E’ to a figure 8, providing more flexibility in circulation and potential sequestration of the floor plates into up to six units per level, each of which could have front doors on the north facade. Structural columns are on a 6m grid, with intermediate dummy columns which channel service runs. These columns also help to achieve a good balance between horizontal and vertical acoustically absorbent surfaces. Each 3m x 3m module has a chilled beam overhead.
The courtyard, enwrapped by Trafford Town Hall and the 1983 offices, was a melée of bin stores, loading space and car parking. Now it is attractively landscaped and enlivened by features such as the terrace of the new coffee bar in the semi-circular space below the town hall’s council chamber, one of many facilities added to get the public through the doors and also fill the council’s coffers. To the north of this café is a transparent, spacious, new double-height entrance area at the end of the internal street, lined by the original brick facade of the town hall on its south side.
Using the stack effect and low-level glass intake louvres at the foot of its south-facing glass wall, the street draws air up from the concrete soffits of the new offices and discharges it at high level.
The floor plates are as deep as natural ventilation allows and a brise soleil reduces solar gain. Aquifers with 18m-deep bore holes, rooftop PVs, SuDS and copious insulation, plus secondary glazing in the town hall also do the sustainability business, generally slashing running costs and hoisting the BREEAM Excellent flag.
Norbury compares the new offices to a Derwent White Collar Factory. ‘Flexible and bespoke are at opposite ends,’ he adds. The new offices do include bespoke elements such as acoustic padding, precast external cladding panels and screens of timber posts, for which it is difficult to share the architect’s passion, but 5Plus’s sprawling, boxy layout has avoided unique, sculptural building volumes - in fact there is little sense of massing at all - opting for elegant restraint and a tough design logic, while letting the bombastic, stepped-clocktowered town hall do the bragging. A case of having your wedding cake and eating it, you might say.