Airport Noise: Should you build or not build around an airport?
Canada will need about 3.5 million additional housing units by 2030 to restore affordability, according to the CMHC. Ontario has among the largest supply gap of any province. To reach the target set by the Housing Affordability Task Force, Ontario must build 150,000 houses per year. That is a big target. Land use and restrictive zoning rules can make it difficult to build housing in particular areas, such as where airport noise is high.
There is no one single answer for the problem of housing supply but there is a need for creative solutions. No one wants to see prime agricultural land lost. Developers are already exploring non-traditional locations and creeping closer to industrial land. And while the demand is high, the discussion becomes how far to push the boundaries. For example, building near airports can look like an attractive option, as they are close to the city with good access to infrastructure. But the question of noise makes it an interesting puzzle.
Airport Noise
Airport noise is measured via noise exposure forecast (NEF) contours. NEF predicts the various levels of airport noise in surrounding areas. It takes into consideration the direction of the runways, how often they will be used, the pattern of flights throughout the day, and other elements to predict noise in neighbouring areas.
Ontario’s current guidelines state no residential development should happen beyond the NEF 30 line. That means residential construction can be permitted near an airport without any restrictions at NEF 25 and lower. For residences between NEF 25-30, noise studies can provide detailed assessments to ensure indoor sound levels are within limits. This can be accomplished with upgraded roofs, thicker windows and walls or upgraded doors as well as other construction modifications.
As the need for homes grow, the question becomes whether to explore building in areas above the airport noise limits. Airports want to protect their business and potential future expansion so they do not want residential housing coming too close. But in some areas, the land is developable, so should noise limits be stretched?
The path for pushing past NEF 30 needs to consider the following.
- Noise impact studies and airport noise: Developers wanting to go above the current boundaries need a report to submit to the municipality and stakeholders. Ideally, it would compare the noise to provincial standards and state what conditions would be like for residents of the development. This could support a request to develop homes.
- Existing residents: There may already be low-density and scattered housing in an area where the sound exceeds the limits, without any health effects. For example, there are subdivisions in Mississauga above NEF 30 and there is signage on the roads and noise warning clauses in the purchase agreements, so it is not a surprise to anyone in the neighbourhood. It may impact house prices but there are people who live in the area and find it acceptable. This may be a path to additional development.
- Accept limitations: Some areas exceed the limits for outdoor or backyard sound level limits but there is often an opportunity to construct residential buildings with indoor spaces well within the provincial sound level limits. It does not mean the outside space is less noisy but there could be common spaces inside the building to compensate.
- Perceived Airport Noise: The difference between a regularly approved NEF 29 development and a dwelling located within the NEF 30 and higher zone may not be that noticeable in many cases. You have to draw the line somewhere, but further study could be warranted to determine what is appropriate.
- Zoning changes: Ontario has issued several ministerial zoning orders (MZO) that have approved developments in lands exceeding the noise thresholds. These have required upgraded construction beyond the requirements of the Ontario Building Code but they can lead to approval for development.
Exceeding the NEF 30 contour is not without risk but it could be worth exploring as developers look for new opportunities. Aercoustics can provide noise impact studies, noise monitoring, and noise investigations to support developers looking to build responsibly in louder than usual environments.
We can help determine airport noise levels and provide recommendations on how to mitigate it for development. We can also help you work with municipalities to understand the impact and if exceeding the current noise recommendations is a viable path.
