Montreal should ban the installation of new indoor fixed appliances, including gas stoves, that use fossil fuels as soon as possible, according to a report by the city's water, environment and sustainable development commission.

The commission also recommends phasing out heating systems that run on fossil fuels in existing buildings and the prohibition, as soon as possible, of connecting new buildings to natural gas lines.

It is also recommended that the decarbonization of Montreal's buildings be coupled with other energy efficiency measures, such as promoting the installation of heat pumps.

The report, which contains 25 recommendations, will be tabled by the commission, which is made up of borough mayors and councillors, at the March municipal council meeting.

These recommendations come after the city mandated the commission to organize a public consultation and find ways to ensure Montreal buildings produce zero emissions by 2040 — a promise made by Mayor Valérie Plante at the Montreal Climate Summit last summer.

Catherine Cadotte, a spokesperson for the mayor, said the administration will take time to analyze each recommendation before making any decisions.

The aim of the summit was to accelerate the shift toward becoming a more ecologically friendly city and buildings account for 30 per cent of Montreal's greenhouse gas emissions, she said.

Of that, the commission says, commercial and institutional buildings emit 57 per cent of the greenhouse gases despite making up just 4.1 per cent of the buildings.

Marie-Andrée Mauger, responsible for the environment on Montreal's executive committee, said, given the scale of the climate crisis, "it is no longer time for half measures".

"We will take the time to analyze all the recommendations and we will follow up on them in the coming months," she said.

The commission's recommendations quickly received support from environmental organizations such as the Association québécoise des médecins pour l'environnement (AQME), Greenpeace Canada, the David Suzuki Foundation and Nature Québec.

However, the Énergir gas utility has come out opposed to the recommendation. Énergir's natural gas network includes nearly 10,000 kilometres of underground pipelines that serve more than 300 municipalities, including Montreal.

In a statement, the company said Montreal would no longer have access to renewable natural gas as a clean energy source if it opts for the recommended bans.

"Recommendations aimed at banning certain types of appliances rather than encouraging the consumption of renewable energy would deprive Montreal of zero-emission solutions that are already accessible, at a good price and that make it possible to effectively manage the energy peak," the statement says.

Énergir's statement said it is pleased to continue the collaboration with Montreal and Hydro-Québec to achieve carbon neutrality in buildings.