Wren’s Library, Trinity College, Cambridge

Client: The Master and Fellows of Trinity College, Cambridge
DB&P's Services: Building Services Consultant Engineers 

Wrens Library

Description of Works:

The Wren Library was completed in 1695 under the Mastership of Isaac Barrow, who persuaded his friend, Sir Christopher Wren, to accept the commission as Architect to the project.

The Library is renowned for it's classical proportions and the clever use of natural daylight which cascades through the opposing East / West window facades to create a crisp and vibrant atmosphere. David Bedwell & Partners were appointed to improve the artificial lighting in the library, essentially to ensure compliance with current regulations without prejudice to the aesthetics of the building. In this respect a range of specialist "background" fluorescent luminaries were discretely installed within the bookcases, these were supplemented with task lighting at desk level. An emergency lighting scheme, comprising floor mounted LED luminaires, was installed at the foot of alternate bookcases thus providing a clearly identifiable passage for safe exit from the building.

As well as being a Grade I listed building, Wren Library houses some of the Trinity College's most notable manuscripts, including an eighth century copy of the Epistles of St Paul, John Milton's shorter poems in his own handwriting and the original manuscript of Winnie-the-Pooh. It was therefore essential that the potential for fire be eliminated / minimised as much as possible – in this respect, and in addition to the conventional fire alarm system, a "Very Early Smoke Detection" (VESDA) system was installed. The VESDA system continuously monitors the clarity of the air via a network of laser-based sampling units; these have the capability of facilitating smoke detection a thousand times more sensitive than normal smoke detectors. Due to the height and open plan aspect of the library, two VESDA systems were required - one monitoring the potential for smoke at floor level, the other at ceiling level. Considerable consideration was given to the location of the sampling units and the installation of the inter-connecting pipework, electrical wiring, etc thus minimising the visual impact that the system would have to the building.

wrens libExtent of Electrical Services:

• General lighting, aesthetic and task lighting

• Emergency lighting

• Replacement of the mains distribution switchgear

• Electrical small power – generally comprising concealed floor boxes augmented with the grilles concealing the LPHW heating system.

• Data and voice communications systems

• CCTV and security systems

• Fire alarm installation – supplemented with a VESDA air sampling smoke detection system.