Skanska is the highest of eight construction companies in the Sunday Times Green List, which ranks the UK businesses doing most to reduce their impact on the environment.
The Swedish-owned construction giant was positioned second, up from fourth place last year, behind overall winner UKOS, an office supplies company.
Willmott Dixon finished sixth, down from third last year, with Carillion up from 11th in 2009 to eighth.
Other construction companies in the top 60 were: Aggregate Industries (24th); Bam Construction (25th); Gifford (37th); Kingspan (38th); Balfour Beatty Construction Northern (60th).
The Building Research Establishment was positioned 26th.
Now in its third year, the Sunday Times Green List takes account of both corporate strategies and the views of more than 26,000 employees, the people who daily put each company's environmental policies into practice.
The rankings were derived from two surveys. The employer survey covered environmental management policies, environmental training and internal consultation, energy consumption, waste production and recycling. It also considered efforts to promote environmental initiatives within business supply chains. This accounted for 70% of the final ranking.
The employee survey put 61 statements to staff which they rated from "strongly agree" to "strongly disagree". As with the employer questionnaire, these statements fell into four broad areas: policies and systems, training and motivation, reporting and communications and environmental performance. Employee responses to these statements accounted for 30% of the final ranking.