Growth in the number of university students has increased demand for accommodation beyond that which universities themselves can provide, provoking private investor supply-side responses such as houses in multiple occupation (HMOs) and purpose-built student accommodation (PBSA). Such developments can lead to high concentrations of students in areas proximate to university colleges and campuses. The movement of large numbers of transitory students into well-established residential areas in university cities, termed studentification, leads to socioeconomic and physical changes. We deploy a mixed-methods approach to analyze qualitative and quantitative data, exploring the role of market participants and revealing the extent and impact of studentification in Durham, a small historic university city in North East England with a high relative student population. The research confirms that studentification was driven by key actors across two distinct phases: conversion of terraced houses into HMOs by private landlords, subsequently restricted by planning regulations, followed by development of PBSA by institutional investors supported by and in collaboration with the local authority and university. Consequently, studentification in Durham has become more dispersed, resulting in increased house prices, rents and competition for investment opportunities farther afield, causing exclusionary displacement of local residents and reducing the supply of family and social housing. We present a detailed timeline of studentification in Durham and reveal a new geography of studentification that extends to peripheral areas of the city and offer some salutary lessons in respect of planning and housing management policy responses to high demand for student accommodation.