Willmott Dixon will plant 10,000 trees a year over the next decade and has already identified sites around the country where it will begin the initiative.
The company made a commitment to plant the trees last year when it launched its sustainability strategy Now or Never.
Its construction and interiors businesses will work in partnership with charities, social enterprises and community groups located close to their projects and offices and will focus on delivering environmental and well-being benefits, rather than solely the carbon benefits of tree planting.
Within the construction business, the London and South team is supporting the National Trust to plant 1,200 trees at Coopers Hill woodland in Egham, Surrey.
In the North, it is also partnering with the National Trust to support tree planting by the River Aire to increase the extent of the woodland and mitigate flooding.
In the Wales and West region, a partnership with Bristol-based environmental organisation Wanderlands will see 2,500 trees planted over the winter.
In the Midlands, Willmott Dixon is working with the Woodland Trust to plant more than 2,800 trees throughout Nottingham alongside the banks of the River Trent.
Finally, Willmott Dixon Interiors will partner with The Conservation Volunteers to plant a minimum of 3,084 trees across London, the Midlands and Leeds.
Julia Barrett, chief sustainability officer at Willmott Dixon, said: “We are delighted to finalise our 2021 programme of tree planting, which is a wonderful and positive legacy for the communities we work in.
“Delivering environmental net gain is critical to our projects, meaning we will leave the environment in a measurably better state than before, by providing valuable habitats to enhance biodiversity, through reducing flooding, and improving air quality. This also helps customers and their local communities by increasing their access to nature, which can measurably improve health and well-being.”