Greening the landscape - Living Site
New rating systems will change our ways
Green roof of the Burnside Gorge community Centre controls stormwater runoff as part of a landscaping strategy that contributes points to LEED Gold certification.
by Adrienne Brown .We think of the landscape as green by default. In reality, it is challenging to achieve this goal in urban areas where requirements are imposed by market expectations, municipal requirements, and a range of other factors.
At the same time, green building rating systems are beginning to demonstrate their power to transform both the market and the regulatory context, and are offering opportunities for landscape architects, engineers, and other designers to apply a variety of new approaches to site development.
The first Canadian system for measuring and rewarding greener approaches to site development was the Canada Green Building Council’s [CaGBC] LEED Certification for New Construction and Major Renovations. Since 2004, this set of guidelines has encouraged developers to address a range of site-related issues including the urban heat island effect, erosion, and water efficiency.
While the resulting attention paid to the environmental aspects of site design has begun to transform the market and design practice in general, there is a need to expand the scope of rating systems and their effectiveness for landscape development. Three current models taking on this challenge are the Sustainable Sites Initiative, LEED for Neighbourhood Development, and the Living Site and Infrastructure Challenge.
Sustainable Sites Initiative
The Sustainable Sites Initiative began in 2005 with a new partnership formed between the American Society of Landscape Architects and the Ladybird Johnson Wildflower Centre. A year later, the United States Botanical Garden signed on, and since then the project has been guided by a product development committee representing almost a dozen stakeholder groups that include the United States Green Building Council [USGBC].
Their goal is to develop a system that will measure and evaluate site developments that may or may not include a building component. Sustainable Sites™ Standards and Guidelines are expected to be complete in May 2009, followed by a rating system in 2011 and the introduction of a Reference Guide by 2012.
One of the primary objectives of the Sustainable Sites Initiative is to incorporate this material into future versions of LEED Guidelines. These new guidelines will expand the role of site design on green building projects to include the potential of vegetation to capture carbon dioxide, affect micro-climate, and increase biodiversity.
They will also address the environmental and economic impacts of landscape waste and soil being diverted to landfill, and will establish parameters by which the most environmentally and socially inspired landscape development can be evaluated for its contributions to both physical and mental health. This system is being developed to complement the LEED for Neighbourhood Development [LEED-ND] rating system, which focuses on the broader context and planning processes.
LEED for Neighbourhood Development
The pilot version of LEED-ND has been developed as a joint venture by the Congress for New Urbanism and the Natural Resources Defense Council to bring together the principles of green building and smart growth.
It was launched last year, and a revised version rating system is expected to be approved by the CNU and the NRDC in 2009.
LEED-ND combines a selection of green building practices from the LEED guidelines with smart growth principles such as development density, proximity to transit, land-use, and multi-modal transportation. The goal is to provide incentives for revitalizing existing urban developments, and for creating new developments that decrease the development footprint while integrating physical and social infrastructure.
Living Site and Infrastructure Challenge
The Living Site and Infrastructure Challenge was published in draft form by the Cascadia Chapter of the US Green Building Council in November 2007. This model is being spearheaded by a group of contributors led by Jason F. McLennan, and is intended to complement his Living Building Challenge introduced a year earlier.
These initiatives move beyond the goal of limiting negative impacts to one of pursuing restorative design that utilizes a set of prerequisites as opposed to a credit system. The difference between mitigating impacts and achieving restorative design is profound, as it has the potential to transform urban development from being “less bad” to being a positive force environmentally. With this in mind, these programs have been conceived to inspire pilot projects that will ideally drive the transformation of landscape, architectural, civil engineering, and planning practice.
The Living Site and Infrastructure Challenge asks designers to meet performance-based prerequisites that address land use and density, the production of renewable energy, the incorporation of nature and natural processes in all major outdoor spaces, and the establishment of human scale.
They require the elimination of stormwater discharge off site and diversion of construction waste from landfill. The prerequisites also preclude the use of potable water from the municipal supply, and the incorporation of ”Red List” materials in projects, and have mandated offsets for loss of habitat and carbon load.
Beyond these more easily quantified factors, the Living Site and Infrastructure Challenge asks designers to include elements that elicit “human delight and the celebration of culture spirit and place,” as well as educational materials and public access to the site to communicate the significance of the project.
The introduction and ongoing development of these three rating systems are meant to complement each other, and to provide different tools for designers and developers to use on projects that vary in scale, complexity, and goals.
The Sustainable Sites Initiative is the most specific and technical in its approach, the Living Site and Infrastructure Challenge is the most aggressive and comprehensive, and LEED for Neighbourhood Development is best suited to projects that involve broader scale planning.
Examples
A recent example of how a landscape development can contribute to a LEED-Gold certification is the Burnside Gorge Community Centre in Victoria designed by Sharp & Diamond Landscape Architects, and completed in 2007. The main goals of this project were to achieve a zero net loss of green space, combined with maintaining pre-development existing stormwater run-off levels.
The stormwater control has been achieved by the construction of a large green roof that covers the structure, permeable paving in the parking area, disconnection of the rainwater leaders, and the introduction of a cistern to capture rainwater.
To support these strategies, the grading techniques and soil depths were planned to maximize the infiltration rate of rainwater. This landscape was treated as a restoration project that replaces green space taken away by the building, as well as providing an environment that supports the sensitive Garry Oak ecosystem.
The planting design is intended to create an environment best suited for establishing the Garry Oak, while providing a functional outdoor space, and a publicly accessible green roof. This landscape development contributes LEED credits for the Water Efficient Landscaping [Water Efficiency 3.1] category through the use of drought tolerant, native species, and an irrigation system that will be disconnected after the planting is established. The green roof contributed credits to the Urban Heat Island Effect section [Sustainable Sites 7.2], while the use of locally supplied products contributed to Regional Materials [Materials & Resources 5.1].
While many projects incorporate the green building strategies carried out at Burnside Gorge, there are also countless site developments that utilize elements of the existing green building rating systems without pursuing certification.
In some cases, this approach can be as effective as going through a formal documentation process, to the degree in which the design encourages transformation of design practices, and markets for both materials and products.
One recent example of this is the Neighbourhood 3 Area Structure Plan for Kelowna completed last year by Stantec Consulting, which incorporates the principles of LEED-ND. Much of the tree cover on this 177-hectare site was destroyed in the 2003 Okanagan Mountain Park Fire; however, natural regeneration is underway and will be enhanced by planting native, drought-resistant species on both private property and public parkland.
In this case, the LEED-ND guidelines have influenced the land use plan, the creation of multimodal transportation networks, and the approach taken by the planners to stormwater management. Neighbourhood 3 will become a home for 2500 to 3500 people over the next 20 years, and over this time Kelowna residents will see the difference such a plan makes to the environmental and social success of the area.
Meanwhile, in Montreal PLANI-CITÉ, Landscape Architects have planned a comprehensive green approach for the Maison de la Culture for the Borrough of Rivière-des-Prairies that includes the retention of an existing wetland ecosystem.
The design team based the plan on the principles included in LEED Canada 1.0 for New Construction and Major Renovations that relate to landscape development, addressing performance criteria that fall under Site Selection, Water Efficiency, Materials & Resources, and Innovation. The resulting site plan focuses on restorative design by minimizing the impact of the building and parking areas, while eliminating man-made drainage infrastructure.
Natural biodiversity of the wetland is being maintained, while runoff continues to feed a small creek that flows into the Rivière des Prairies. For this project, plant species have been selected for their ability to filter run-off, and both rain gardens and dry gardens have been designed and positioned to respond to the specific conditions.
As site and landscape designers, we are at an early stage in the development of systems to measure and optimize site design and environmental processes. However, both the Sustainable Sites Initiative and the Living Site and Infrastructure Challenge promise to bring many new ideas to the table, thus making a substantial contribution to the evolution of design practice in the coming decade.
.
»»» Related Information:….
Big box site design
Mountain Equipment Co-op Distribution Centre
by Bryce Gautier.
Is it possible to design an industrial suburban development that is efficient in terms of construction, operations and maintenance, yet takes a responsible approach to site design and makes a positive contribution to its surroundings?
This was the question posed to the design team by the client Mountain Equipment Coop in relation to its planned new distribution centre in Surrey, BC. In response, Sharp & Diamond Inc. worked as part of a dedicated consultant group to create a site plan focusing on a range of sustainable design techniques that are achievable, cost-effective and relatively low maintenance.
Some of the sustainable approaches implemented include:
- A carefully organized site plan that places the fundamental functions of a working environment [parking, loading and access] in the natural context of a preserved wood lot, enhanced to improve its ecological function.
- An innovative storm water management plan where precipitation from the building and surrounding hardscape is directed through a series of vegetated swales, infiltration basins, cisterns and permeable paving areas.
- Large drifts of native planting, grasses and seasonal meadows planted in lieu of unused, water-hungry lawns to create a low maintenance street edge that is affordable to install and maintain and adds aesthetic interest.
- Recently completed, the MEC Distribution Centre can be seen as a prototype for a new and healthier approach to the design of the industrial landscape.
Self-Report to the AIBC to receive 1 Core Learning Unit
Print and retain completed questionnaire
.Print this article | Send by e-mail