Pre-tax profits at the Belfast-based firm also showed a modest increase to just over £200,000 as the firm expanded its UK presence.
Ray Hutchinson, managing director of Gilbert-Ash, said: “While market conditions remain highly competitive, we are encouraged by the current order book and anticipate a further significant increase in turnover in 2016.
“Our strategic focus on further developing the business in Great Britain has led to an increase in tender opportunities, which will ensure continued growth in the medium term.”
He added that last year Gilbert-Ash raised staff numbers to 180 and expanded its base in London, moving to larger premises in the centre of the city.
Looking ahead, the firm is in talks with Cadogan Estates about converting a 19th Century red brick mansion house and apartments into a luxury boutique hotel located on Sloane Square in London.
The firm is also hoping to secure the job to find a new home for Mountview Academy of Theatre Arts in south London and has just started a student accommodation block for the University of Surrey at Manor Park in Guildford, continuing a long association with the university.
Last December Gilbert-Ash handed over a new hub hotel for Premier Inn at Tower Bridge in London. Described as, ‘the only hotel in the world that can be controlled from your wrist’, the hub hotels are next generation, technology enabled hotels aimed at digitally savvy city travellers.