This year's questionnaire for the 1999 consultants survey included a new section: performance ratios. Practices were asked to calculate their fee-earning capacity by dividing their annual fee income by the number of chartered staff.

Taking the top 250 consultants across all disciplines, 100 firms have been ranked in order of the average fee-earning capacity of a chartered member of staff. This new way of ranking consultants provides a different snapshot of the market, and one that makes interesting reading.

Engineers again dominate the top 10, but many of the big names from the top 250 consultants are nowhere to be seen. Absent are WS Atkins, Ove Arup and the like, while in come names such as architect Gensler and engineer Sandberg.

Four engineers are among the top fee-earners per qualified member of staff; three are multidisciplinary companies, one is an architect, another a surveyor and the last a project manager. Top of the list is 20-strong Sandberg, with each qualified member of its UK staff bringing in £300 000 worth of fees a year.

Partner Neil Sandberg puts this down the company being able to extend the areas it works in – "extending value" he calls it – so that it now offers a range of services from advice on speculative developments right through to advice on building maintenance. It has also found a profitable new market predicting the thermal capacity of buildings – profitable. "We moved into this market last year and are pleased with the way it's going. It's got more growing to do," he adds.

Architect Gensler is placed fourth. Its staff bring in £250 000 each; Foster and Partners, by comparison, is in 72nd place. Its staff bring in a mere £117 155 a head. Fees for others at the bottom of the chart go right down to just over £100 000 per qualified member of staff. This figure is all the more shocking considering that many non-chartered staff also contribute to bringing in fees - if they were included, fee-earning capacity would be even lower.

Gensler managing director Tony Harbour says the firm's success is in part due to its policy of working out its fees by calculating man hours per project and presenting this to clients. "I keep hearing we're rather expensive, but I keep telling people it's reasonable," says Harbour. He says when he shows clients the work broken down into man hours they usually do not query the fee.

Top 250 consultants