The firm said it was close to trading out all legacy contracts as it revealed pre-tax profits edged up from £200,000 to £900,000 in the first half of the year on turnover marginally ahead at £122m.

But the group’s Cardiff office, which is part of the second biggest of four regional arms, suffered a disappointing performance due to a challenging student accommodation project due to close out in October.

Central & West divisional revenues for 2015 also have been affected by the same principal contractor withdrawing from a secured project where T Clarke was also its partner.

The turnaround in London started to drive margin growth in the first half of the year and work is due to start on Angel Court, Mizuho Bank, Principal Place, Rathbone Square, and London Wall Place.

Mark Lawrence, chief executive, said: “The group looks forward to the improving market conditions particularly with our forward visibility for next year and beyond.

Our order book now stands at a strengthened £320m against £275m last time and provides a platform to grow the business and improve the profitability of the group.”

Overall the group has secured 92% of its target revenues for 2015 and £155 million for delivery in 2016.

“The signs of improvement in our London markets continue to be seen and we expect to see further opportunities for margin growth next year and beyond in our wider markets across all our UK locations,” he said.