What is the main characteristic of a 'greenfield site'?

A greenfield site is defined primarily as an area of land that has never been built on before, making it untouched by previous construction activities. This characteristic differentiates greenfield sites from brownfield sites, which are previously developed and may require redevelopment or clean-up before new construction can take place.

The allure of greenfield sites often lies in their availability for new development, whether for residential, commercial, or industrial uses. They provide opportunities for fresh planning, allowing developers and urban planners to design new communities that fit modern needs without the constraints and complications often associated with existing structures or contaminated land typical of brownfield sites. This aspect of greenfield sites contributes significantly to urban expansion and can influence planning policies aimed at sustainable development.