As response to the coronavirus (COVID-19 or SARS-CoV-2) pandemic, REHVA experts drafted a guidance document on how to operate and use building services in areas with a coronavirus outbreak to prevent the spread of COVID-19 depending on HVAC or plumbing systems related factors. This REHVA document has been updated (as of 3 August) and considers the best available evidence and knowledge to date, utilizing an ongoing Dutch literature review elaborated by dr. Francesco Franchimon, complemented by international REHVA experts as a joint effort. Due to the ever-changing information about the disease, the document will be updated and complemented with new evidence when it becomes available. REHVA thanks the co-authors of this document for their much-appreciated contribution. On August 3, the REHVA COVID-19 guidance document from April 3 has been updated