This paper introduces an innovative tool developed under the EU-funded Smart Square project, designed to simplify the calculation of the Smart Readiness Indicator (SRI) for buildings. This tool addresses the urgent need for an efficient and user-friendly methodology to assess building smart readiness, offering a streamlined approach to SRI assessment. Its architecture and calculation procedures are crafted to facilitate rapid and straightforward SRI calculations, making it accessible to a diverse range of stakeholders, including building owners, facility managers, and policymakers. Crucially, this tool is also tailored for call centres, presenting a novel method for building certification. The paper explores the rationale for utilizing call centres in building certification, demonstrating how this strategy can significantly enhance the efficiency and scalability of SRI assessments. By leveraging a user-centric design, the tool efficiently processes building data to produce accurate and comprehensible SRI calculations. The paper showcases examples of certificates generated by the tool, highlighting its practical application and ease of generating clear results. This tool significantly advances the promotion of smart and sustainable building practices across Europe, aligning with the EU's objectives for energy efficiency and digital transformation in the built environment.