A revolutionary library and trend-setting apartment block are two architectural gems opening their doors this weekend.

Herne Hill’s Carnegie Library and Pullman Court in Streatham will be the focus of free guided tours as part of the capital’s Open House Weekend. The annual event, run by architecture charity Open House, gives Londoners a glimpse of historic buildings that would normally be wholly or partly closed to the public.

Carnegie Library was the first in Britain to give readers the chance to browse the books themselves - rather than asking a librarian to fetch what they wanted from an archive.

The Herne Hill Road library was built in 1905 after a donation by Scottish philanthropist Andrew Carnegie, and is now Grade II listed. In recent years the library’s opening hours have been reduced and in 1999 it was threatened with closure. Tours will take place every hour, on the hour, from 10am to 4pm on Saturday.

Also welcoming visitors is the modernist Pullman Court in Streatham Hill. Built in 1936, the apartment block is a rare British example of the early International Style and also Grade II listed.

Its architect, Sir Frederick Gibberd, went on to design Heathrow and Liverpool’s Catholic Cathedral. He created Pullman Court at the start of his career, in a bid to show that good quality flats could be used to house the country’s growing ubran population. It will open on Sunday from 12am to 5pm.

Open House Weekend was launched in 1993, and this year about 700 of the capital’s buildings are expected to feature in its programme. For more information about the event visit londonopenhouse.org.