One St. Peter’s Square


One St. Peter’s Square in Manchester provides 268,000 sq ft of office space in the heart of the central business district. The building has been designed to meet the extremely exacting demands of a BREEAM Excellent 'Grade A’ compliance.

The challenge

In order to achieve the required acoustic performance both horizontally and vertically, any potential weak points had to be investigated and it has been necessary to upgrade the curtain wall mullions. A hollow mullion is an ideal conduit for flanking sound transmission and even if all other elements, such as the floor slab, partitions or ceilings perform well acoustically, an untreated mullion can drag the overall DnFw performance of the façade below its required specification.

Our solution

Working with the main contractor, Carillion and Red Architectural, the façade installers, SIDERISE supplied products from the mullion and transom range for the project: SIDERISE V baffle - MI5 & SIDERISE HB insert - MI6 mullion inserts. These inserts are available for any profile and are cut to the exact internal dimensions of the mullion or transom. The range of inserts have been shown by test to be capable of improving performance by up to 9dB.

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