Building contractors are finding sustainable construction to be a growing market similar to design firms. The growing market for green design can be seen in the results of ENR's Top 100 Green Contractors list. The Top 100 companies generated $44.99 billion in contracting revenue in 2013 from projects registered with and actively seeking certification from third-party ratings groups under objective sustainable-design standards. Green contracting revenue has increased in all buildings sectors except for government offices and the religious-and-civic markets, which have been off 5.9% and 16.9%. Sustainability is also beginning to break out of a project-by-project basis and moving into a broader neighborhood concept, driven by local codes and regulations.