This paper introduces the harmonized accessibility methodology (HAM) that has been defined and deployed in the context of the ACCESSIBLE project. HAM is aimed to harmonize existing collections of related design knowledge, such as heuristics, guidelines, standards, etc., and thereby provide the grounds for defining ontology-based rules and, and thereby implementing, within ACCESSIBLE and beyond, automated accessibility assessment of ICT designs and developments. Ultimately, ordinary developers will be enabled to conduct rapid, yet specialized, accessibility assessments focused on any relevant disability types, assistive technologies, platforms, and contextual conditions.