For over a century, zoning laws in Canada have favored single-family homes over structures like apartment buildings that encourage urban density. This has led to a housing shortage, high prices, sprawl, and car dependence. However, Canada is now offering billions in infrastructure funds to provinces with the condition that they eliminate single-family zoning and allow the construction of fourplexes. This policy, aimed at expanding housing and mitigating climate change, is a significant departure from traditional zoning practices. Researchers believe that denser housing reduces emissions significantly and leads to more efficient use of materials and energy. If successful, Canada’s approach could inspire similar policies in the U.S. and promote the construction of more climate-friendly housing options.