Urban development is often confronted with a lack of available space. Brownfield sites offer great potential for sustainable urban planning because of their often-central location and the benefits associated with their redevelopment. Although the interest in brownfield regeneration has led to a lot of research on this topic, there is not yet a comprehensive review of brownfield research. In this review, we analyze the research on brownfields and provide a picture of the published case studies. We focus primarily on brownfields research in the United States, Europe, and China. This exploratory research is based on an analysis of the published scientific literature available in the Web of Science database. Initially used in North America, the term brownfield quickly became popular in the rest of the world, particularly in Europe. However, with the exception of the United States, there is no specific legislation for these sites; their protection is often based indirectly on directives or laws related to soil pollution, biodiversity or the environment. The perception of the potential use of brownfield sites varies considerably from one part of the world to another, and international collaborations between researchers from different parts of the world remain limited. Most of the described reuses of brownfield sites are forms of soft reuse (53%), and the type of reuse of a site depends more on the surrounding urbanization levels and the specific region than on the past use of a brownfield site. Despite the continued interest in the rehabilitation of these sites, especially due to the increasing demand for nature in the city following the Covid-19 crisis, many questions regarding the future of brownfield sites remain unanswered. The factors influencing their successful redevelopment are unclear, and further research is urgently needed to ensure a truly sustainable re-use of these sites.

Brownfield technosol restoration represents a real opportunity to minimize land consumption, but it often requires intensive intervention and reconstruction, leading to soil donor site destruction and potential pollution. Using a former oil refinery brownfield site, this research compares the short-term (one year) impact of localized restoration methods, including soil surface scarification, organic matter addition, earthworm inoculation (locally and commercially sourced), on the soil fauna and vegetation properties. Vegetation rapidly covered the bare soil, but few significant impacts were observed in terms of the soil or vegetation structure. The initial positive impact of soil scarification on surface compaction quickly faded and earthworm inoculations did not seem to impact soil characteristics. Natural soil colonization by vegetation or fauna was the major driver in soil modification. The analysis of an intermediate reference showed a delay of multiple decades between vegetation, fauna density, and soil structure improvement, as well as the achievement of a soil of “good biological quality”. We conclude that the use of engineer species on brownfield soil in its actual form is not an early restoration step but should be tested in later steps (e.g., when organic matter content is sufficient). However, additional research is needed in engineer species selection and multi-compartment approaches. A better understanding of the impacts of natural colonization in the early stages of technosol restoration is also essential for restoration techniques’ improvement.