The restoration of run-down urban areas by the middle class (resulting in the displacement of low-income residents) WordNet 3.0 & Open English WordNet

Gentrification is the process of changing the character of a neighborhood through the influx of more affluent residents and businesses. Wikipedia

Urban socioeconomic process Wikidata

The transformation of a neighbourhood's demographic and character that ensues when affluent individuals move in, causing real estate value (and thus rent and property taxes) to increase and forcing less affluent long-time resident to relocate. OmegaWiki

The renewal and rebuilding that accompanies the influx of middle class or affluent people into deteriorating areas and often displaces earlier, usually poorer, residents; any example of such a process. Wiktionary

Process of renewal accompanying an influx of relatively affluent people. Wiktionary (translation)