International policies indicate the building sector as one of the most promising for sustainable development. According to the Intergovernmental Panel on Climate Change (IPCC), it has the greatest and cheapest potential for delivering significant greenhouse gas emission reduction. However, early experiences of sustainable construction have shown that both a social and a technical transition are required. Consequently, the changes in organizational aspects of firms involved in construction represent an urgent research theme. This paper investigates how inter-firm relationships are changing as the sector moves towards green building. The organizational model between firms is described at the integration level with suppliers, the integration level between the general contractor and the design team, the degree of specialization of involved firms and their sustainability certifications. These features have been analyzed in case studies collecting data through interviews. This paper compares organizational aspects in traditional and green buildings. Results suggest that green buildings are associated with inter-firm relationships of comakership with suppliers and with the design team, and with firms with a portfolio focused on sustainable projects. Finally, among the case studies, sustainability related certifications are scarcely related to the greenness level of the building.

Sustainability is no longer being questioned as a passing trend, but has been recognized as innovation’s new frontier. However, the complexity of environmental issues requires that firms collaborate with a wide range of external parties as they can supply environmental knowledge and competencies outside a firm’s main domain. This study proposes and tests a model suggesting that inter-organizational collaborations positively affect environmental performance, analyzing the behaviours of the largest publicly traded U.S. companies. The dependent variables are different types of companies’ environmental performance, as reported in the U.S. 500 Newsweek’s 2010 Green Ranking. Data for the independent variables (collaborations undertaken with several types of actor and concerning environmental issues) have been collected through the content analysis of companies’ environmental/sustainability reports and/or their website section devoted to environmental sustainability. Collected data have been analyzed through regression analysis. Results show that inter-organizational collaborations with actors both within (suppliers and customers) and outside the supply chain (government agencies and NGOs) are beneficial for a company’s overall environmental performance, the management of its environmental footprint, and a company’s environmental reputation.