BRE DG526 PDF

INTRODUCTION

There are still hundreds of high-rise LPS dwelling blocks in the UK, which potentially contain about 50,000 dwellings. These generally comprise flats, but in some cases the accommodation is in the form of maisonettes. In addition, it is estimated that there are in excess of 1000 low- and medium-rise LPS dwelling blocks in the UK.

In essence, most LPS dwelling blocks are gravity structures, as are traditional masonry-constructed buildings, which rely on their self-weight to maintain their stability when subject to lateral loads, such as those created by the wind. They typically comprise precast reinforced concrete floor and roof components spanning onto storey-height structural precast (plain) concrete wall panels. The vertical loads associated with the self-weight of the building and the imposed loads applied to the floors and the roof are carried to the ground through the structural wall panels, which also provide stability against lateral loads.

Block owners have an ongoing responsibility for their safety, which requires periodic inspection and structural assessment of such buildings. The UK requirements for this particular class of building stem from the 1968 collapse of the south-east corner of Ronan Point, a 22-storey LPS dwelling block^[1].

Historically, the guidance used for the structural assessment of LPS dwelling blocks for accidental loads has been the Ministry of Housing and Local Government (MHLG) Circulars 62/68[2] and 71/68[3], which were produced shortly after the Ronan Point incident. MHLG Circulars 62/68 and 71/68, along with various other related guidance documents from that era, were never withdrawn, and notionally remain in force today. However, that guidance has become outdated by subsequent developments.

This Digest summarises the revised technical performance requirements and the associated guidance for undertaking a structural assessment of an LPS dwelling block for accidental loads, and also describes facets of the programme of work undertaken to support their development.