The firm hit its target by driving down carbon emissions by half over last year and investing in a carbon offset scheme backing global decarbonisation projects.
Mace has additionally offset estimated carbon emissions associated with its employees moving to home working as a result of the global pandemic.
The business has also pledged to set out its new carbon reduction targets as part of its 2026 business strategy due to be launched in February.
Mace said it cut carbon emission by half through a variety of trials and solutions including a 75% increase in renewable energy, a 75% reduction in business travel emissions, a ban on diesel generators and an increase in the use of cement alternatives.
The outstanding carbon emissions were offset through investment projects led by Carbon Footprint, a UK sustainability consultancy with a portfolio of Gold Standard and Verified Carbon Standard programmes across the globe.
The offsets have been divided across six international programmes that provide solutions to climate change.
They include decarbonising electricity grids through solar power and wind farms in India, providing support and equipment to remote communities in Africa to improve their energy efficiency, reducing deforestation in Brazil and planting trees in the UK.
Mark Reynolds, Group Chief Executive at Mace, said: “I’m delighted that we have realised our ambition in the same year that we set our target.
“My hope is that our net-zero carbon position will inspire the industry to take greater action as a whole.
“Only by working together, sharing our learning and supporting each other’s efforts will we make the difference that’s needed.”
Reynolds added: “Our journey doesn’t end here. We have new, tougher targets that will see us reduce our carbon footprint by 10% each year and deliver biodiversity net gain with the creation of 500 hectares of new habitat.
“Equally, in 2021, we will look beyond our own footprint and continue to support and measure helping our clients reduce their carbon footprint and scope 3 emissions.”