Once targeted by the road protest movement for building roads through areas of outstanding natural beauty, support services and construction company Carillion has become a beacon of good green practice.

Fifteen years ago, taking on board the concerns of the green lobby, the firm, then part of Tarmac, developed an environmental policy and set up an independent advisory committee before broadening its initiatives to cover wider sustainability issues. The Wolverhampton-based company, which was involved in developing Nottingham's tram system, recently helped protect an internationally important nature conservation site while building a new section of the M6 between Carlisle and Guardsmill in Cumbria.

Employees think the company does a lot for the environment, giving it a positive green score of 78% in our staff survey. They think Carillion is getting better at protecting the environment (85%) and that its impact on it is improving (81%).

Indeed, electricity and gas consumption both fallen by more than 20% in the past year, helping the firm towards its target of halving its carbon emissions by 2010 against a 2006 baseline. Its plan to fit submeters — which show much energy is being consumed in individual rooms or by particular appliances — will bring further cuts.

The firm is committed to constantly improving its environmental performance even as it grows and is currently tackling the rise in fuel consumption and office waste resulting from its acquisition of support services company Alfred McAlpine last year, which added more than 100 sites to its portfolio. Supportive employees should make meeting the 40% target reduction for waste at head office locations an achievable one. Our survey reveals workers are aware of the environmental implications of the work they do (81%) and know that how they do their job has a bearing on the environment (83%). They know about Carillion's environmental policy (84%) and an abundance of green information via e-mails, the intranet, on notice boards and at staff meetings keeps them fully informed of environmental issues and campaigns (81%) to help them play their part.

From its offices to its construction sites, Carillion's mantra is reduce, reuse, recycle and recover wherever possible. Last year, the company began using vans which cut the engine when the vehicle is stationary in traffic to reduce carbon emissions. Policies for reducing construction waste include using Forest Stewardship Council certified timber, donating wood offcuts to local schools for use in technology lessons, shredding material for use in landscaping and specifying no or minimal packaging from suppliers.

A bid to produce zero net waste at its Bridgend Asda project, which involved recycling and reusing more material than was wasted, saved Carillion £276,000.

A Carillion team working at Catterick garrison in North Yorkshire is even trialling the use of recycled cooking oil in one of its vans. Fifty litres of oil will be taken from the garrison kitchens each week and processed on site to produce vehicle fuel and a glycerol by-product, which can be used for cleaning the van.

It is clear that most people in the business don't still associate green issues with beards and sandals (80%) and that staff see Carillion's environmental commitments as being very serious (83%).