The “EcoShopping” project aims to produce a practical holistic retrofitting solution for commercial buildings, reduce primary energy consumption to less than 80 kWh/(m2.year) and increase the proportion of Renewable Energy Systems (RES) to more than 50% by using state of the art solutions. The project intends to use and integrate available products and technologies; along with a network to accurately monitor the environmental and occupancy parameters to allow the Building Management System to have better control of the building and fully exploit the thermal mass. This paper: ‒ Introduces the EcoShopping project and the consortium carrying out the work. ‒ Describes the case study building and the initial targets for carbon reduction. ‒ Discusses the results of Work Package 2: which is an assessment of national building codes, Energy Performance Buildings Directive (EPBD) implementation, performance standards and good practice. This study identifies that building regulations and their associated codes lay down minimum levels of performance for non-domestic buildings but do not attempt to prompt best practice. Best practice performance criteria were identified for the majority of technology areas. For such a case study, it is essential that the methodologies are comparable with those already in use and that technologies match or exceed best practice criteria already published. In addition, producing auditable numbers is essential to showing transparency in how the energy savings claimed are justified.