The Climate Resilience Factor

In 2022, the Southwest borough in Montréal modified its urban planning by-law to integrate a climate adaptation requirement for new real estate developments.

The Climate Resilience Factor (CRF) is a tool that is part of the third phase of the borough’s regulatory changes, in line with the Southwest borough’s Local Action Plan for Ecological Transition and the City of Montréal’s Climate Plan. This is a weighting method for construction projects aimed at improving the quality of life and landscape of neighbourhoods while ensuring the ecological value of developments. For example, as soon as they are built in the Southwest the new buildings will contribute to the reduction of urban heat islands (UHI), which are particularly present in this old and highly mineralized sector, and will promote biodiversity through greening, as well as sound management of rainwater to avoid combined sewer overflows. These building design elements will also have the co-benefit of helping to reduce greenhouse gas (GHG) emissions through reduced energy consumption and carbon capture.

Unlike more conventional regulations, the CRF, also known as the biotope coefficient, does not only assess the amount of green spaces on a land, but also the quality of the plantation and their ecological benefits or co-benefits, as well as complementary measures in a project, such as the presence of green walls or roofs on the building.

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Understanding and Assessing Impacts

The built environment in Montréal’s Southwest borough has faced many challenges in recent years; a victim of its attractiveness, the already dense and mineralized borough is facing significant real estate development. Combined with an increase in heat waves and torrential rain events projected in Montréal’s 2020-2030 Climate Plan, the borough is seeing increased pressures on its infrastructure and risks to its population. The Urban Planning Division team also noted that many projects complying with the greening by-law ultimately had inadequate green spaces to have a real impact on UHI or site water retention. This is why they, in collaboration with the Office of Ecological Transition and Resilience, decided to use the “biotope coefficient” model to develop a regulatory tool specifically targeting green spaces, soil permeability and biodiversity conservation.

Identifying Actions

The biotope coefficient is a regulatory tool developed in Berlin in the 1990s and adopted in several cities around the world, including Seattle and Helsinki. Adapted to dense and mineralized environments, it aims to protect vegetation and promote soil permeability. As this concept had never been implemented by a Canadian city, the borough team took the time to adapt it to the local climate context. They also took the time to develop a criteria grid that would be consistent with the municipal and provincial legal framework in order to have a real impact on the design of new real estate projects.

The ecological targets selected for the local grid are thermal regulation, rainwater absorption, pollutant capture and the ability to provide wildlife habitat. The team decided to establish three main categories of requirements to achieve these goals:

  1. the permeability of surfaces in contact with the ground;
  2. the quantity and quality of plantings; and
  3. the greening of buildings

The team then developed a weighting system inspired by existing grids to establish the score for the elements in the different categories. For example, a permeable soil gives a maximum score (value of 1) compared to a non-permeable surface. Fill soil grounds were even weighted at 1.5 because of their importance in retaining water on site and providing habitat for wildlife. The local prevalence of underground parking lots occupying the entire lot is one of the reasons which explain this choice. This complies with greening regulations by installing grassy surfaces, but are in fact green roofs and do not allow for deep water infiltration. The grid also provides for the greening of buildings by integrating green walls, green roofs and even plants in planters. In addition, distinctions are made between different types of vegetation, for example between small and large trees, in order to promote a significant canopy to fight against UHI.

Implementation

During its development, initial versions of the grid were shared with local real estate developers who had projects awaiting approval. This provided an opportunity to test which requirement and weighting were most likely to influence project design. This dialogue allowed the grid to be adjusted so that it would have the desired influence at the time of its uptake. On their end, developers were able to work upstream on new proposals adapted to the new regulatory context. The project team also coordinated with the stormwater management team to standardize the language used in the regulations. The goal was to avoid confusion regarding the different standards established in the two regulations and to use complementary and consistent definitions.

Testing the grid also allowed us to identify areas of the borough where it was becoming difficult to apply, especially in some very dense residential areas. For example, it is easier for a small plex-type building in need of expansion to meet the criteria required to obtain a permit than a high-rise building requiring underground parking. More precisely, the Griffintown area, adjacent to the downtown core, presents challenges as the majority of development projects in that area are towers requiring underground parking.

Outcomes and Monitoring Progress

The Climate Resilience Factor (CRF) officially went into effect in December 2022. It is an index that expresses the ratio between the sum of the climate-resilient areas, which are the landscape elements, and the land area on which they are located. Projects submitted for a permit are analyzed through the criteria grid and the result is a coefficient indicating whether the project meets the climate resilience targets set by the administration. To be granted a permit, the project must meet the minimum target required. This target varies depending on the use and location of the building.

As the uptake of the regulatory tool occurred shortly before the publication of this case study, the results of this project are currently limited but are already beginning to shine through in the projects under consideration. Rather than limiting their landscaping to a few shrubs, the new developments that take part in the criteria grid test incorporate a greater variety of vegetation, as well as stormwater retention solutions in the form of outdoor ponds with permeable bottoms and rain gardens, as opposed to the previously favoured underground retention ponds.

The borough also retains a certain discretionary right, out of concern for the many old buildings on its territory, as well as sectors where the built environment or other major constraints make it difficult to apply the measures of the grid to new developments. The borough will give itself at least one year after the adoption of the by-law to review it and make adjustments.

Next Steps

As mentioned earlier, the borough plans to make future adjustments to its criteria grid and regulations once the effects of its implementation have been more clearly documented. In particular, the borough will monitor the effects of the CRF and its various iterations on multiphase projects, which will go through different rounds of permit delivery. In addition, consideration will be given to the integration of negotiable bonuses to encourage the integration of the grid criteria while taking into account other regulatory constraints (e.g. on the issue of building heights and footprint). The urban planning team that worked on the project is also collaborating with other interested Montréal boroughs, including Mercier-Hochelaga-Maisonneuve, Plateau-Mont-Royal and Montréal-North, for the eventual adoption of similar by-laws on their territories. Moreover, communication was maintained throughout the development of the initiative with the City Centre’s urban planning division in order to initiate a discussion on the integration of a similar tool into the city’s future urban plan.

Resources

Link to Full Case Study (in French only)