Chairman Michael Graham revealed the target as part of a new five-year strategy to restore profitability and optimise the business size at around £900m.
In the year to March 2019, revenues stabilised at £735m, after several years of growth, while pre-tax profit fell 37% to £8.2m.
Graham said the latest accounts showed stability across all divisions, with each returning a profit.
“This will provide us with a solid platform to continue to grow sustainably,” he said.
“We have also produced a healthy balance sheet, with strong cash balances of £63m and no trading debt.
“Our intent is to continue to invest in the balance sheet to ensure that we can be selective about the projects we work on and the partners we work with.
“Our focussed approach to work winning has accounted for our current order book of £1.2bn.”
He added: “This leaves us well placed for 2020 with strong levels of secured work, and a forecast revenue of £875m.
“2020 should also see Graham return to the top quartile of industry profitability with margins in excess of 3%.”