Household expenses for daily mobility, on the one hand, and housing, on the other hand, are significant components of household budgets and difficult to manage for a significant portion of the population. Although related, these two major expenditure categories are traditionally analyzed separately and rely on separate databases, which prevents the identification of common issues and the joint analysis of their determinants. The concept of residential cost, which encompasses both expenses related to primary housing and reversible daily mobility, aims to overcome these analytical difficulties. However, various methodological challenges arise when attempting to operationalize the residential cost and provide a measurement and indicators, such as the burden ratio (residential cost as a proportion of household disposable income). This presentation at the 6th Swiss Mobility Conference (2023) addresses the methodological issues and initial results from estimating the residential cost of households in the extended Grenoble metropolitan area (359 municipalities, approximately 825,000 inhabitants). Within this scope, the latest certified Cerema Household Mobility Survey (EMC2) was conducted in 2019-2020 by SMAGG, the public transport authority of Grenoble. It includes an additional module for collecting residential cost housing + transportation data. Firstly, the presentation introduces the developed methodological framework (definitions, databases used and linked, estimation methods, and indicators). Secondly, initial results on the residential cost are presented, distinguishing within this framework the household energy expenses for housing, mobility-related expenses, and other expenses for housing and mobility. The estimated values of residential cost indicators for different socio-demographic, economic, and residential household categories are discussed. This work is carried out as part of the COUT-RES project funded by the AURA region, led by LAET, in collaboration with CEREMA, EMSE, IRSTEA (INRAE), the Urban Planning Agency of the Grenoble region, and the SMTC, the public transport authority of Clermont-Ferrand.