Meg Needle is a green roof expert who loves to talk about sustainability. This makes her a great fit for her educational and institutional clients, who often use the living roofs for teaching their students. Needle, AIA, LEED AP BD+C, GRP (Green Roof Professional – accreditation through Green Roofs for Healthy Cities), began her career as the first female draftsperson in a small architectural firm in Ohio. She currently resides in Atlanta and works as an Architect and Associate at Lord Aeck Sargent Architecture (LAS).

Lord, Aeck and Sargent has studio specialties for commercial projects, including higher education and institutional clients. Needle works in the Education/Arts and Culture Studio and has been involved with academic buildings, student housing, museums and interpretive centers.

“I love working with institutional clients because they have a great interest in creating lasting buildings that are expected to serve students and visitors for many years,” she said. “All of our projects have a sustainable aspect to them as that is just part of our corporate design philosophy, and that, LAS has brought to our clients long before sustainability was a buzzword.”

Needle explains that sustainable design has been at the center of the firm’s practice since its inception and thinks that philosophy continues to give them an edge and keep their firm relevant across all specialties. “Bringing talented and dedicated staff and listening carefully to our clients’ needs are paramount,” said Needle.

Green Roof Guru

Needle has worked on multiple garden roof projects encompassing both intensive and extensive green roofs. She defines intensive green roofs as assemblies with more than 6 inches of growing media, while extensive green roofs are shallower, with six inches or less of growing media.

She’s worked on roof plazas with landscaping amenities that would definitely be categorized as intensive green roofs. “Those types of projects still have their place where accessible green spaces on elevated structures are a priority,” she said. “Intensive green roof installations generally include landscaping, trees, shrubs, sod, or other ornamental plantings, as well as hardscape for walks, etc. These applications require a lot of structural and waterproofing TLC and can be quite expensive.”

Extensive green roof technology brings many of the advantages of intensive green roofs but doesn’t have complicated structural or waterproofing implications, which makes them more widely applicable.

Needle explains that she has been very fortunate to be involved in several significant projects that were a catalyst for her to dig into the latest extensive garden roof research. One of those pivotal projects is the Gwinnett County Environmental and Heritage Center, completed in 2006. This facility serves as an interpretive education center for the county school system as well as regional audiences with a primary focus on water.

“A green roof concept really embraces their educational mission and was adopted as an important feature of the center’s design from the very beginning. With approximately one acre of sloping green roof area on a wood framed structure, this project’s challenge gave me the chance to research the very latest extensive green roof technology,” she said. “That experience really exposed me to the current green roof movement and since then, I’ve become the ‘green roof specialist’ in our firm.”

As great as green roofs are, Needle makes a point to note that they are not always the best fit for every project and do require a commitment from the building owner for long-term care as they are really a garden. Highly reflective roofs, while they don’t have the storm water management qualities of a green roof, can be good choices for mitigating the urban heat island effect and are proven to provide cooler roof temperatures that can be a real energy conservation strategy in cooling dominated climates.

Ahead of the Curve

Needle keeps up with the latest technological developments in roof assemblies, “Building technologies continue to evolve at logarithmic rates and garden roof assemblies are not an exception,” she said. “The documented performance of green roofs, along with more proven systems and materials have allowed them to really begin to gain broader acceptance by design professionals, construction trade contractors and building owners,” she said.

“As the building industry, as a whole, really embraces sustainable building practices, green roofs will continue to be an arrow in the quiver for integrated design strategies. In the right context and for a client who embraces the roof as a garden space, green roofs can definitely play their part in a holistic sustainable building design solution.”

Sustainable Home life

Even when away from the firm it seems that sustainability is a big part of her personal life as well. Needle reveals that she and her husband spend lots of time on small and large home renovation projects and find it therapeutic working in the garden, including their 230-square-foot garden roof.

“I really do enjoy sustainable building design. I like working on projects at home where I can use my hands and enjoy finding clever ways to reuse things,” she said.

“The challenge of ‘cutting the fat’ by minimizing wasted resources fascinates me. I loved integrating our solar hot water system that serves as a sunshade and also provides some radiant space heating in the winter as well as my compact disk shingle installation that makes our roof peaks sparkle and reflect heat in the summer.”

When she is not doing home renovations you can find her at the beach spending time with her husband Ron and two sons, Simon and Joshua.

In the future, Needle hopes to remain a resource for LAS and the industry, as well as her clients. She states, “What’s the point of learning a trade if you can’t pass on what you’ve learned to the next generation?”

The Basics of Green Roof Assemblies

According to Needle, green roof assemblies include both the “black arts” (roofing and waterproofing) and the “green arts” (growing media and plant materials). Extensive green roof systems — those with 6 inches or less of growing media — include the following basic key components:

•          A robust roofing/waterproofing membrane system is really important. Generally a waterproofing like rubberized asphalt, TPO or PVC installed in an inverted roof membrane assembly (IRMA) configuration (in which the membrane is fully adhered to the deck with insulation on top) is a good choice.

•          A drainage mat to ensure unimpeded sub-surface runoff with landscape fabric to prevent silt migration into the drainage infrastructure is almost always required by roofing manufacturers.

•          Growing media of engineered soils that include expanded shale or similar aggregate that resists compaction, resists erosion, drains well and has a capacity to retain water are key qualities that are necessary for the majority of the mix.

•          Plant selection will influence the growing media composition somewhat. Finding local resources that can mix the engineered growing media is important since transportation costs can have a big influence on installation costs.

Tips from Needle on green roof design include:

•          Capturing rain water or condensate are great ways to help with irrigation needs.

 •          Locating a green roof “downstream” of a higher roof such that it can treat the runoff from the other roof area as well as its own is a great strategy for maximizing the storm water effectiveness of the green roof.