Wednesday, November 17, 2010

Headquarters Profile: Green Roof

This is the second of three posts about our new headquarters at 3030 12th Street NE and our tree yard at 3015 12th Street NE in the Brookland neighborhood. We are excited about our new home, and we wanted to share with you some of the green features we have implemented.

Close-up of a green roof at the new Casey Trees HQ.

The 10,000 square foot Casey Trees administrative building is a half new, half renovated office building on the 12th Street NE corridor in Brookland. The key feature of the building is a green roof system that covers just over 25% of the roof area. There are three green roof sections covering part of the first floor and garage, and the upper story roof is covered by a white "cool roof" which reflects sun off the building and keeps the interior cool. Part of the reason for constructing the green roofs on top of the first floor was to ensure the visibility of the roof for staff and visitors. We planted three different types of green roofs, each with more than half a dozen varieties of herbaceous flowering plants (primarily the sedum genus). The design of the green roof maximizes water absorption, while keeping the building much cooler than a conventional roof would in summer months.

If you haven't seen a green roof up close before, you may be surprised to find that they are not simply elevated grass lawns. In fact, they aren't made of grass and you actually shouldn't walk or sit on top of a green roof unless you are maintaining it. It is built only for the purpose of gathering as much rainwater as possible. If there is excess water, it filters through pebbles surrounding the platform and flows to storm gutters. The storm gutters at the Casey Trees site empty into our rain garden and bio-retention site. Even though these roofs are utilitarian and efficient in nature, they are beautiful to behold.

A section of green roof is unrolled like a carpet.

Non-profit green roof advocates DC Greenworks and Level Green Landscaping worked together to get our green roofs constructed and planted in a matter of days. This project would not have been possible without funding from the District Department of the Environment (DDOE). We hope to use our green roof design as a model for sustainable development in DC, as part of our participation in the Sustainable Sites Initiative™ (SITES) Pilot Program.

More pictures of the new green roofs.

Read the media release about the move to our new headquarters, and stay tuned for more blog posts about the eco-friendly features of the site.

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