The Westminster government has published guidance, to help providers of higher education in England, on reopening HE buildings and campuses. This is available here: https://www.gov.uk/government/publications/higher-education-reopening-bu....
A few key points:
It makes specific reference to libraries, stating Library service providers have been required to cease their business during the coronavirus (COVID-19) outbreak, apart from servicing orders made online or by telephone, text or post. Libraries can open from 4 July in a COVID-secure way. Libraries Connected has drawn up guidance for public libraries to support reopening that will also be relevant for university libraries. (https://www.librariesconnected.org.uk/news/new-guide-help-libraries-reopen).
On social distancing it says: From 4 July, where 2 metres is not viable, reducing the distance down to a minimum of 1 metre can be used but only if appropriate mitigation is in place. You should consider and set out the mitigations you will introduce in your risk assessment.
In large part it points to existing guidance – e.g. https://www.gov.uk/guidance/working-safely-during-coronavirus-covid-19/l... and https://www.gov.uk/guidance/working-safely-during-coronavirus-covid-19. On staff safety it refers to https://www.gov.uk/guidance/working-safely-during-coronavirus-covid-19 and https://www.gov.uk/government/publications/covid-19-guidance-for-the-pub...
It says that institutions should “identify the appropriate mix of online and face-to-face content for each subject, reflecting what will maximise learning as well as supporting staff or students who cannot attend campus, and enabling the provider as a whole to minimise transmission risk.”