Living Roof & Living Wall Centre for Interactive Research on Sustainability

Living Roof & Living Wall Centre for Interactive Research on Sustainability

Building

Peter Busby, Design Director, Perkins + Will

15.1 Overview

15.2 Description

Living Roof

The roof of the lecture hall is covered in a garden of native plants. The plants include a wide variety of ground cover, shrubs and woody materials, all native to the lower mainland. The low profile plants require a relatively shallow amount of growing medium (45 cm) and are hardy enough to withstand some variation in the amount of irrigation. Both deciduous and evergreen plants were included to create a diverse habitat for insects and birds. The green roof provides an interesting view for inhabitants of the upper office floors, whose windows face inward, across the building courtyard. The landscape is built on top of a membrane type roof structure specifically designed to accommodate it. The growing medium is held in place by an erosion net and L-shaped soil retainers, below which a corrugated drainage layer catches and channels excess water off the roof. The membrane is sandwiched between a protection mat and rigid protection board to protect it and the rigid insulation below from penetration by growing plant roots.

Roof Layers: (top to bottom)

  • Soil Erosion Net
  • Light Weight Growing Medium
  • Soil Retainer
  • Living Roof & Living Wall Centre for Interactive Research on Sustainability
  • Geogrid
  • Drainage Layer/water Reservoir
  • Protection Mat
  • Water Proof Membrane
  • 13 Protection Board
  • Rigid Insulation
  • Vapour Barrier
  • Plywood
  • Laminated Wood Structure

The living roof is an integral component of the building’s water management strategies. The roof reduces stormwater runoff by absorbing and utilizing the rain falling on it as irrigation. The rainwater is supplemented by reclaimed water treated by the Solar Aquatic System (see Section 13.0 Reclaimed Water). The roof also indirectly reduces the burden on the municipal sewage treatment system; in the summer months when the building is sparsely occupied, the solar aquatic system imports sewage from the municipal system in order to maintain the volume of treated water available for irrigation in the driest months of the year. The need to provide steady year-round irrigation was one of the driving factors in this innovative “sewer mining” solution. The living roof is therefore supplied with nutrient and phosphorous rich water throughout the year, independent of both rainfall and the level of inhabitation in the building.

15.4 Campus Context

UBC Campus Plan

The UBC Campus Plan emphasizes the natural setting of the campus and encourages the engagement of the community within it. The Plan also encourages high standards of sustainability performance for buildings, landscapes and infrastructure, by supporting innovation and experimentation through demonstrative living laboratory projects in new developments. Part of these efforts include a natural systems based approach to issues like water management, identifying waste streams as resources and using plantings native to the campus environment. The living walls and especially the living roof of the CIRS building are demonstrative examples of ways to meet these objectives, using plantings to provide both functional services and focal points of environmental engagement for the inhabitants and visitors to the building.

UBC Design Guidelines

The UBC Design Guidelines were developed to help coordinate the design of projects on the Point Grey campus, with the intention of accentuating UBC’s western coastal setting and improving the cohesiveness of the built and natural environments of the University. Projects are encouraged to integrate the design of new buildings and the surrounding landscapes as single compositions, and provide strong indoor-outdoor connections, both physically and visually, between the inhabitants’ interior working and social spaces and exterior environment. The green roof of the CIRS building, with native plantings and habitat, provides this connection. The Design Guideline emphasizes using passive design strategies to address lighting and heat gain in buildings, and encourages integration of such features into the overall design of the building. The guide prioritizes illustrative examples of natural cycles in the built environment to raise public consciousness of sustainable building practices. The living wall is an example of a passive design strategy (“passive intelligence”), creating a dynamic façade that responds naturally to the amount of shading required throughout the year, as well as beautifully highlighting natural cycles of plant growth.

UBC Technical Guidelines, Division 7

While the green roof provides many functions, including a key component of the wastewater system and a habitat, it is primarily a roof, and must perform as part of the building envelope. Division 7 of the UBC Technical Guidelines governs buildings envelopes, emphasizing thermal and moisture protection, including air barriers, insulation, cladding materials, types of roofs, fire stopping, sealants and accessories. Of particular relevance are sections 07200 Insulation Systems, 07500 Membrane Roofing, 07700 Roofing Accessories, 07840 Fire Stopping and 7900 Sealants. The design of the living roof must maintain these requirements, while incorporating the dirt, water and plants on top.


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