Introducing the Blue/Green Roof at 150 West 4th Avenue

Targeting LEED Gold, as part of Vancouver’s Green Building Policy for Rezonings, TKA+D’s 150 W 4th Avenue Laboratory and Office project is nearing completion. We are excited to reveal that it will yield one of the first “Blue/Green Roofs” in the region. This innovative roof not only supports biophilic design principles that seek to improve the quality of this workplace, but it also provides a practical solution to meeting the project’s municipal stormwater requirements.

A low maintenance sedum cover creates extensive “Green Roofs” located on the roof and two occupied podium levels. A flat rainwater detention pond chamber below the soil creates a “Blue Roof”. The resulting “Blue/Green Roof” is multi-functional stormwater management system which automatically feeds the green roof as a resource rather than becoming a waste product.

This approach to meeting increasing stormwater regulations, not only reduces the impact on the building’s loss of valuable indoor areas due to large detention tanks, but it also relieves the ever-increasing stress on the city’s infrastructure while adding beauty to the design.

  • The entire system has a 70m3 of storage capacity which can handle 10-year storm events.
  • The system utilizes both “retention” in soils and “detention” in the pond chamber.
  • It is anticipated that the system will provide passive irrigation to the green roof for up to 3 weeks in the summer.
  • The system is designed to provide a flourishing green roof with relatively low maintenance. Should the chamber dry out in the summer, the system will automatically top up with water.

In addition, the project generally benefits from the green roof’s ability to:

  • Extend roof life with extra layer of protection from elements.
  • Reduce energy demands,
    • Lower summer temperatures than a conventional roof and mitigates Urban Heat-Island effect.
    • Increase thermal insulation in the winter.
  • Pre-filter and clean stormwater.
  • Absorb pollutants and CO2, improving air quality.
  • Provide a more natural habitat with increased biodiversity within the city.

More information and resources