The iconic American Life & Accident Insurance Company building in downtown Louisville, Kentucky originally gained notoriety for being the last notable work of the famous German architect Ludwig Mies van der Rohe. However, this impressive building still had room for improvement. Recently, the landmark site was able to increase its sustainability and prominence in the area by installing the largest privately-owned vegetative roofing system in Kentucky.

Planning for the new roof began back in 2009 when it became clear that the existing 20-year old roof was no longer in good-enough working condition to protect the structure. The original re-roofing plan called for a 2-ply modified bitumen roofing system with a white, reflective cool roof coating on top.

With input from the asphalt membrane manufacturer and American Roofing & Metal, a premier commercial, industrial and residential roofing contractor, the owner decided to take a slightly different direction on the project. A modified bitumen system, upped to 3-ply for added redundancy and protection, would still be the roofing system of choice. However, instead of adding a reflective roof coating on top, they would install a sustainable vegetative roof instead.

Johns Manville, Green Roof Solutions and American Roofing & Metal worked together to provide a complete green roof system for the American Life Building. Green Roof Solutions worked with American Roofing and Metal to help their team understand the installation and logistics that are unique to this particular green roof assembly.

Brian Barry of Green Roof Solutions said, “The green roof included a protection layer, root protection, drainage layer, separation fabric, edge restraints, engineered media, a blended sedum pre-vegetated mat (for instant green) and inspection chambers over the roof drains to allow access.” Green Roof Solutions had personnel on site for five days to make sure that any questions regarding the installation were addressed in a timely manner and maximize efficiency making this a win-win project for everyone.

The vegetation used for the roof was primarily Sedum blankets provided by vegetative roofing products company Sempergreen. Each blanket was made up of ten to twelve different species of Sedum. Biodegradable and grown on a coconut fibre carrier, laying out the blankets did not prove to be a problem for the team.

In total, more than 12,900 square feet of the blankets were used for the installation. They were installed over approximately 5 inches of growing media, according to Boyd. Sedum plants are capable of storing water which helps deal with runoff water from the building and lessens the need for constant upkeep.

Nana Lampton, chief executive of American Life and Accident Insurance Co. of Kentucky, has been a roof garden proponent from the start. Enlisting the assistance of Bernheim Arboretum and Research Forest, three small 12-foot-square test beds were also installed to trial various native and adaptive species to Kentucky. “One plot, modeled after a rock garden, includes snow-in-summer and ice plant. Grasses — like purple love grass and blue fescue — grow in the middle plot. The third plot emulates a Kentucky cedar glade, with gray goldenrod and prickly pear,” (Courier-Journal, 2011).

Turner Construction Company Turner managed the interior fit-outs and renovations of multiple floors within the facility, as well as the original construction of the Mies van der Rohe-designed American Life & Accident Insurance Company building in 1974.