Peri-urban Expansion in Ikorodu, Lagos: Extent, Causes, Effects, and Policy Response Funmilayo Mokunfayo Adedire 1 # Springer Science+Business Media B.V., part of Springer Nature 2018 Abstract This paper examines the extent, causes, socio-economic and environmental effects, and policy response to expansion in Ikorodu, the most urbanised peri-urban settlement in Lagos State, Nigeria. Primary data was collected through the administra- tion of 384 questionnaires to household heads in purposively selected 18 settlements in the study area. Secondary data was sourced by conversion of analogue spatial images, the land use maps, and satellite images of the study area to digital format. Quantitative data was analysed using descriptive statistics while qualitative data was analysed using time series and satellite image analysis. Findings show a spatial expansion due mainly to housing development and socio-economic activities. The existing expansion in the study area is accompanied with socio-economic, socio-cultural, and environmental challenges. It is recommended that the state government should create a balance between the pace of development and infrastructural provision in the peri-urban settlement to limit expansion-related challenges in the study area. Keywords Environmental challenges . Peri-urbanisation . Policy response . Settlements . Spatial expansion Introduction With limited land supply and continuous population growth in Lagos metropolis, spatial expansion through the creation of satellite towns in peri-urban areas becomes the available means of mitigating the unabated housing challenge and spatial demand accompanying urbanisation (Towry-Coker 2002). Presently in Ikorodu, Nigeria, there is a rapid change in land use especially from agricultural to residential land use in rural areas on the outskirts of metropolitan cities. Law et al. (2008) through their Urban Forum https://doi.org/10.1007/s12132-018-9336-5 * Funmilayo Mokunfayo Adedire funmidire@gmail.com 1 Department of Architecture, University of Lagos, Lagos, Nigeria