Expert-produced information and data hold significant potential for adoption by decision-makers; however, this potential can be compromised by barriers related to language, communication channels, and formats. The literature emphasizes the differing languages, timelines, and incentives between specialists and lay decision-makers who seek practical solutions to real-world issues, rather than theoretical dilemmas. We conducted a mixed-method study, based on a survey and interviews with Italian regional lawmakers and local decision-makers in land-use planning. This is an area characterized by high levels of technicality and hence appears challenging to most decision-makers. We discovered that when they easily grasp the meaning and implications of policy documents, their understanding seems more influential in their legislative behavior. Consequently, a key challenge in promoting evidence-informed policy-making seems to translate expert knowledge into accessible languages and codes for laypeople and to present it in practical and concise ways.