This Digest gives guidance to professional engineers on the structural appraisal of existing buildings, including making a structural appraisal for a material change of use.

Part 1 considers the overall regulatory requirements, and in particular the disproportionate collapse issues associated with Requirement A3 of the Building Regulations Approved Document A: Structure. It describes what constitutes a material change of use and reviews the Building Classes (see Section 5 of Approved Document A: Structure). It also examines means of reducing sensitivity to disproportionate collapse in respect of Building Classes 2A, 2B and 3, as defined in Table 11 of Approved Document A. The provisions in the structural Eurocodes for reducing sensitivity to disproportionate collapse are also discussed.

Contents

1 Introduction

2 Reasons for undertaking a structural appraisal

3 Regulatory requirements and disproportionate collapse issues

3.1 Definition of a material change of use

3.2 Building Classes as defined in Approved Document A

3.3 Other circumstances and considerations

3.4 Requirement A3: reducing sensitivity to disproportionate collapse

3.5 Provisions in the structural Eurocodes for reducing sensitivity to disproportionate collapse

4 Other UK legalisation

A4 12pp, 1 line drawing, 3 photos.

Available on or after 1/6/2012.