With the adoption of the Green Building Actxxi (2006) and the Clean and Affordable Energy Act (2008), Washington DC became the first city in the U.S. to pass legislation that requires green building certification, as well as energy and water benchmarking, for both the public and private sectors. This policy legacy has prompted an impressive growth of green buildings and, as of January 2016, the city contained more than 119 million square feet of LEED-certified real estate from more than 650 LEED-certified projects.

However, realizing that building codes are a jurisdiction’s primary opportunity to tailor specific mandatory requirements for all buildings, in March 2014, in addition to its adoption of the latest version of the International Energy Conservation Code, the city adopted the DC Green Construction Codexxii based on the International Green Construction Code (IgCC). It extends the scope of green building requirements to all commercial construction projects larger than 10,000 square feet and all residential projects that are at least 10,000 square feet and 4 stories or higher.


The adoption of the comprehensive green code was possible thanks to an early engagement of relevant stakeholders from the private sector, careful consideration of local context and market conditions, and provisions for flexibility within the code. The new code was also adapted to the DC context and carefully integrated with all of the city’s existing codes and regulations (e.g. DC Plumbing Code, Zoning Code, Stormwater Regulation, etc.). Sections that were duplicative of other initiatives were deleted or amendments to other codes were made.

The code also provides flexibility to deliver the requirements in different ways. For example, projects can elect to achieve the ASHRAE 189.1 standard or LEED, National Green Building Standard, or Enterprise Green Communitiesxxiii certification as an alternative to the code requirements. In addition to the standard required sections of the green code, DC adopted an amended version of the IgCC’s Appendix A, from which project teams can choose a certain number of project electives from the overall list of possible electives.

Training has also been an important part of code implementation. Since 2012, more than 75 trainings have been given and several critical resources have been released, including a Green Building Program Manualxxiv for green building policy in general, and standard code submittal templatesxxv and sectional reference guides that aid in energy and green code compliance.

Reasons for success

The successful adoption of the ambitious DC Green Construction Code was possible thanks to a collaborative approach to its development and adoption, and strong commitment to implementation among private-sector stakeholders. Two existing instruments also facilitated the code’s adoption and successful implementation, namely the Green Building Fundxxvi (funded by revenue from permit fees) and the Performance Bond & Binding Pledgexxvii (a penalty for non-compliance with green building certification).

When/why a city might apply an approach like this

Cities in general should consider this approach, especially to guarantee energy efficiency and green practices in new construction and major retrofits for municipal buildings and to spur similar action in private buildings. Before adopting a construction code with mandatory green building and energy efficiency standards, it is advisable to start with certification requirements for individual municipal projects to build administrative capacity, uncover in practice any potential conflicts with existing building and related codes, and demonstrate success of the approach. This can later facilitate integration of a green construction code within the existing regulatory environment. 

C40 Good Practice Guides

C40's Good Practice Guides offer mayors and urban policymakers roadmaps for tackling climate change, reducing climate risk and encouraging sustainable urban development. With 100 case studies taken from cities of every size, geography and stage of development around the world, the Good Practice Guides provide tangible examples of climate solutions that other cities can learn from. 

The Municipal Building Efficiency Good Practice Guide is available for download here.  The full collection of C40 Good Practice Guides is available for download here.  

All references can be found in the full guide.

  • Economic
Key Impact
As of January 2016, the city contained more than 119 million square feet of LEEDcertified real estate from more than 650 LEED-certified projects
Share article

More Case Studies