Green Roofs

The Project

Thanks to funding from Environment and Climate Change Canada’s Eco Action Community Funding Program, the Mount Allison Students’ Union’s Green Investment Fund and the Small Change Fund, EOS Eco-Energy worked with community partners in Sackville, NB to install two extensive green roofs. The sites enable local residents and students to learn more about green roofs and their benefits for managing stormwater. The green roofs also create more outdoor community spaces, which is especially helpful during the current COVID-19 pandemic. 2020-2021 was a planning and design year. 2021-2022 saw roofs installed and promoted. Find out more about the project below:

The Goals

To reduce runoff from buildings and manage stormwater with green infrastructure;
To promote the benefits of green infrastructure, specifically green roofs;
To increase community resilience to climate change; and
To education the public, including youth and small businesses, about community resiliency including green roofs.

EOS staff and volunteers plant the green roof at the Sackville Town Hall in summer 2021.

What is a green roof?

Green roofs (also called vegetated roofs or living roofs) are planted gardens on the tops of buildings, covering all or part of the roof.

How are green roofs constructed?

An engineer will need to do a load assessment to make sure the building can handle the weight of the green roof and is constructed in a suitable way (for example: has an inverted roof design, existing drainage system, etc.). A building permit may also be required. Green roofs have a waterproof membrane which is placed over the existing roof, root barrier, drainage layer, filter layer, moisture retention layer, and growing medium (a type of special soil), and plants. You may also want to install a leak detection system and/or a sprinkler system.

What are the benefits of green roofs?

Green roofs have many benefits. Most importantly they absorb rainwater and help to reduce local flood risk. They also provide additional insulation for the building and can extend the life of the roof. Green roofs increase biodiversity, create natural habitat for birds, insects and other wildlife. They also help to lower urban air temperatures by mitigating the heat island effect, filter pollutants and sequester carbon. They create attractive spaces that can help reduce our stress, connect us with nature, and provide space to grow food. The many co-benefits of green roofs will enhance the resiliency of our region to climate change impacts.

Types of Green Roofs

EXTENSIVE ROOFS: Low maintenance shallow coverage, ranging in depth from 2 cm to 15 cm, much lighter and cheaper than intensive green roofs. This is the type of green roof we installed.

Example of a simple extensive green roof

INTENSIVE ROOFS: Have a minimum depth of about 15 cm, supporting wide variety of plants, even trees. They are heavier, more expensive and require more maintenance.

Example of an intensive green roof with trees

The Project’s Green Roofs

Sackville, NB Town Hall

EOS revived the original green roof area by planting new native species. The green roof area was also extended. EOS staff and volunteers planted native flowers and grasses, strawberries, blueberries, and a variety of herbs. This green roof is open to the public (during regular Town Hall office hours) and is considered a public roof top park. It has patios, picnic tables, benches, and solar lighting as well. It is located off the second floor (which can be accessed by an elevator if needed).

The Town Hall’s existing green roof in the background with newly planted extension in the front.

McCain Student Centre at Mount Allison University

The green roof at Mount Allison University is located on the McCain Student Centre and is wheelchair accessible. The green roof layers were installed in late 2021 and will be planted with a variety of native flowers in spring 2022 by students, staff and volunteers.