Vol. 23, No. 3 May 18, 2015

DDOE Green Area Ratio

Effective October 1, 2013, the District Department of the Environment (DDOE) implemented an environmental sustainability zoning regulation called the Green Area Ratio (GAR). This regulation sets standards for landscape and site design with the goals of reducing stormwater runoff, improving air quality, and incorporating sustainable program elements into the site design early in the design development process. Under the new regulations, developers and builders are required to engage a Certified Landscape Expert (WSSI has 22 such experts!) to prepare and certify a site landscape plan and landscape maintenance plan which complies with the GAR requirements before they are submitted to the Department of Consumer and Regulatory Affairs (DCRA). Current versions of the GAR Guidebook and associated forms and worksheets are available for download on the DDOE Website.

Key elements of the GAR landscape submittal requirements include:
Existing tree inventory
Preservation and removal plan for existing trees (completed by an ISA Certified Arborist)
Specifications for soil improvement
Schematic irrigation plan (when applicable)
Location, size, and species of all proposed landscape elements
Landscape maintenance plan
Post-construction site inspection checklist

A Certified Landscape Expert is a:
A Professional Landscape Architect (PLA) licensed in Virginia or Maryland (D.C. has no such certification);
International Society of Arboriculture (ISA) Certified Arborist;
A Professional Horticulturist in Maryland; or
Landscape Contractors Association MD-DC-VA Certified Landscape Technician.

Who Must Comply?
All new buildings (permitted on or after October 1, 2013) that require a Certificate of Occupancy must comply with GAR requirements. Additions and interior renovations to existing buildings must also comply with GAR when the cost to construct exceeds 100% of the assessed building value within any twelve-month period.


There are several exemptions, such as:
Single family residences;
Buildings that do not require a Certificate of Occupancy;
DC Water wastewater treatment facilities;
Some interior renovations of existing buildings (as specified in the regulations); or
Historic resources certified by the DC Inventory of Historic Sites or State Historic Preservation Officer unless undergoing renovations of more than 50% gross floor area.

Plan Submittal Process
GAR plans for new buildings should be submitted during the Foundation-to-Grade (FD) or Civil (BCIV) permit application process to allow coordination with stormwater plan review. GAR plans for additions or interior renovations should be submitted when applying for the Building Permit (B). All plans are submitted to the DCRA, routed to the DDOE Watershed Protection Division and reviewed for compliance with the regulations.

GAR Construction Compliance & Certificate of Occupancy
The Certified Landscape Expert is required to sign off that all GAR environmental performance features have been installed according to the approved plan. The approved landscape management plan should be provided to the property owner to inform them of the maintenance and management activities required by the plan. The Landscape Expert must then meet with the DDOE Inspector to review and sign the DDOE Landscape Checklist.

Please note that a Certificate of Occupancy will not be granted until the signed Landscape Checklist is received.

For additional information please contact Matt Landes, Barry Duncil, or Dillon Conner.