National Library of Scotland, Causewayside Building

Client: National Library of Scotland


The Causewayside Building is located on the corner of Causewayside and Salisbury place, on the site of the former Middlemass Biscuit Factory.  It is the largest property within the National Library of Scotland estate. The building was constructed in 2 phases and designed to provide areas for staff, public, map room and collection storage initially with the flexibility to convert staff and public areas to collection storage over time.  Phase 1 to the north was completed in 1987 and Phase 2 to the south was completed in 1994.



The building had shown failures in the stonework, glazing system and roof coverings.  Investigations concluded that to resolve the issues it was necessary to replace the external envelope. LDN Architects approach was similar to that for a listed building. Proposals were developed and new cladding materials and systems selected to retain the overall appearance of the original building whilst incorporating more robust and simplified details to ensure a weathertight envelope with significant improvements in airtightness and thermal performance.


The existing roof cladding was replaced with a new standing seam aluminium system capable of covering the main roof areas without cross joints whilst accommodating movement. Sheets are colour matched to the original building with long joints aligned to the existing grid to replicate the original design. The system incorporates insulation to meet current standards. A dark grey single ply membrane has been used on less visible areas of roof to deal with complex interfaces and in the existing planters. Existing roof access walkways and steps were also replaced and extended.


The existing glazing system, which utilised a bespoke 100x100mm aluminium frame, has been replaced with a standard, mullion drained curtain walling system, double glazed into a 60x160mm frame. The frame is colour matched to the original building and aligned to the existing grid to replicate the original design. The different frame size is accommodated at the perimeter of screens with insulated flashings. Abutment upstand flashings have also been increased to improve weathering.


The existing stonework was replaced with a new, more durable sandstone, similar in appearance to the existing and to match the original stone profiles. In some locations drips have been introduced at wall heads to improve weathering.  New insulation was incorporated in the cavity which, although limited in thickness, provides an improved thermal performance.


The construction works were completed over a 3 year period during which time the building remained occupied and open to the public.



Get in touch to see how we can help you

Contact us →