Pre-tax profit slipped by over a quarter to £4m at the Hertfordshire-based firm on revenue up 5% at £107m.
Chairman Michael Masterson said: “Pricing remained challenging in a very competitive market and costs continued to rise especially so in tradesman’s wages and management salaries.”
He added: “Nevertheless the directors consider a 3.7% profit margin after tax to be satisfactory.”
Masterson said: “Profit margins in the current year remain demanding but increased activity in London and the South East enables the directors to report another successful year.”
He added: “We have been trading successfully since 1980, we have the financial strength of a larger construction company but we strive to retain the family culture with all our directors actively involved with our clients and projects.”
Getjar, which employs around 120 staff, saw the balance sheet strengthen to £13m in the year to August 2018 from £10m in 2017.