The privately-owned firm, which has offices in Scunthorpe and Leeds, established a new Energy Waste and Renewables (EWR) division to focus on complex civil engineering projects.
The group’s turnover increased from £118.2m for the financial year 2016-17, to more than £176m for the 2017-18 financial year.
A spokesman said: “However, the investment in restructuring the group to create the platform for future growth, saw profitability decrease marginally from the £1m pre-tax profit recorded in 2016-17 to a small pre-tax loss of £0.5m for the financial year 2017-18.
“The group maintained a strong balance sheet with accumulated cash balances of £30m at the year-end, no bank debt, and a strong forward order book. These cash balances were up on last year, increasing from £18.1m for the 2016-17 financial year.
“Net assets, meanwhile, decreased slightly to £14.3m for the 2017-18 financial year.”
Bob Vickers, chief executive, inset, said: “Despite the challenging conditions in several of our key markets, together with investment in the restructuring, we have delivered another credible financial performance.
“Whilst the markets in which we operate remain challenging and we believe this will remain so for the foreseeable future, I am sure that the restructuring we have undertaken, particularly within the construction area of our business, will create the focus and drive to enable us to continue to deliver successful projects.”