Well cost data is considered from many sources: GETEM, Lukawski et al. ( ), Klein et al. (2004), GeoVision (Lowry et al., 2017), and GEOPHIRES. Well cost models from GETEM and GeoVision are partially bottom-up models that try to build a well by summing individual costs, while Lukawski et al. (2014) and Klein et al. (2004) are top-down models that aggregate available drilled well cost data. Klein et al. (2004) is a subset of the geothermal well data used in Lukawski et al. (2014). The bottom-up models tend to be more accessible and are more easily adapted for use in genGEO.