The Emerald Hills residence is located approximately 800 feet from Edgewood Park and Natural Preserve (EPNP) – a landscape of significant ecological value, with many rare plants and animals. It is particularly known for its serpentine ecology:
“The most important driver of Edgewood’s extraordinary ecological diversity is its 160 acres of serpentine soils. These soils contain heavy metals, which can be toxic to plants, and low levels of the nutrients that plants need to grow. Over millennia, certain plants and animals have adapted to living in these thin, gravelly soils. Because most non-native species cannot tolerate serpentine, Edgewood’s serpentine grassland and chaparral communities form a natural preserve of native plants and animals that depend on them. Many of Edgewood’s rare species are serpentine endemics, meaning they’re limited to serpentine soils. The role these soils play
at Edgewood is magnified by their role in California’s remarkable biodiversity. Serpentine outcrops cover just 1% of California, but they account for 12% of the state’s endemic species. Serpentine lands, like those at Edgewood, are unique and with protection will continue to offer refuge to a rich mosaic of California plants and animals.” https://friendsofedgewood.org/learn-about-edgewood-park

The landscape between the site and preserve is a mix of very low-density housing and consistent tree cover, predominately oak trees – a keystone species of high value to biodiversity. This connectivity of wildlife habitat links EPNP to the site, and as a result, the landscape is well poised to make a positive contribution to this existing network of biodiversity. The site is also located within the wildland-urban interface and is listed as Very High fire hazard.

In addition to the threat from development, serpentine habitats are threatened by nitrogen pollution from car emissions which allows non-native plants to outcompete the rare serpentine plants. One species of particular significance is the federally threatened Bay Checkerspot Butterfly, which relies on serpentine grassland ecologies. This butterfly had disappeared from EPNP in 2002 but with human intervention was reintroduced to the park in 2007. Ongoing efforts are being made to reestablish the butterfly populations.

The catalyst for this project is a house addition, designed by See Arch. The entrance to the house is to be reoriented to the south edge, and a new wing is added that extends the house into the landscape. We worked collaboratively with the clients and See Arch to design a landscape that is both integrated with the architecture and takes full advantage of the views to the hills beyond. Designing different areas for outdoor relaxation and entertaining was another focus, as well as providing areas for kids to play. We also incorporated defensible space measures for fire mitigation.

The planting in the backyard will be entirely locally native with a focus on habitat planting.  Plant selection, spacing, and layout will be responsive to the proximity of the house. For example, planting in fire zones 1 and 2 will include clusters of compact shrubs, groundcovers, and grasses planted amidst gravel, stones, and boulders. The planting will be low-lying to prevent ‘fire ladders’ to adjacent trees. Moving further away from the house into fire zones 2 and 3 the planting becomes taller and wilder with clusters of shrub planting. The planting will still has fire breaks of gravel or mulch between clusters. 

Field collective developed a comprehensive concept design, that included two different concept schemes and multiple perspective imagery. Through a collaborative process, one concept was selected and refined, and we are now in the process of taking the final design through entitlements.