Greenfield development refers to building on previously undeveloped land—typically agricultural fields, natural areas, or other open spaces at the edges of existing communities. This contrasts with infill or brownfield development that builds on already-developed or previously-developed land within existing urban areas. Greenfield development enables new suburban neighbourhoods but raises concerns about loss of farmland and natural habitat, car-dependent community designs, long commutes, and the high cost of extending infrastructure to serve dispersed development. The infrastructure cost of greenfield development typically exceeds its tax revenue for years or decades, potentially subsidized by existing taxpayers. Provincial planning policies increasingly direct growth toward existing built-up areas rather than greenfield expansion, though housing demand and developer economics continue driving greenfield projects. Sustainable greenfield development incorporates compact design, transit access, and preservation of natural features.