Guide to Conversion of Traditional Buildings

An introduction to safety standards in traditional buildings

The purpose of section 4 of the Technical Handbooks is to ensure that buildings are accessible and as safe as possible for everyone to use. Historic buildings and landscapes were not designed to be readily accessible to everyone, and the emphasis on, and understanding of, health and safety issues was very different when they were first built. We therefore must deal with complex contradictions when attempting to adapt these buildings to allow safe, convenient and unassisted access throughout, while preserving their historic character.

The application of these standards to the conversion of traditional buildings has the potential to cause significant disruption to their historic character and fabric. It is important when attempting to design and work with traditional buildings that their unique character and challenges are fully understood as well as their potential for change. It is therefore recommended that their cultural significance is defined and understood clearly and in detail.

The usual methodology for this is a conservation (or heritage) statement. The more significant and sensitive a building or structure is, the more careful evaluation of the fabric and detail is required. A conservation statement sets out why the building is significant and what fabric is important to that significance. Ideally, it should also identify sections of buildings that are likely to be more adaptable to change. This allows both general design proposals and specific alterations to be assessed to ensure the most successful solution for both the performance of the building and retention of cultural value.

Features such as materials, doors, finishes (panelling, decorative plasterwork, historic decorative schemes etc.), and the importance of internal spaces and their arrangement should all be considered when trying to develop a scheme to improve accessibility and safety. The front elevation and principal rooms and spaces (such as entrance halls) are typically more difficult to alter without affecting their architectural or historic interest (character). Therefore, there is normally a presumption in favour of adapting less important rooms and spaces as a way of preserving a building’s wider character and significance.

Experience suggests that most buildings can be successfully and effectively altered as part of the conversion process. In some cases, a reversible addition which avoids the removal of historic fabric may be preferable, but this must be balanced with the visual intrusion that these solutions often have. It may also be possible to design a set of alterations or interventions which are clearly modern, using a consistent set of materials and details throughout the building, provided this is carefully considered in relation to the building’s key characteristics. It is important to be aware that improvements to accessibility can also help many sections of the community beyond those who are identified as disabled.

When attempting to make traditional and historic buildings fully accessible, practitioners should carry out a further investigation in the form of an ‘access audit’. This should define where and how an existing building creates a barrier to access. For further information on what should be included in an access audit, reference should be made to BS 8300-1: 2018: ‘Design of an Accessible and Inclusive Built Environment’, Part 1: External Environment- Code of Practice and BS 8300-2: 2018 ‘Design of an Accessible and Inclusive Built Environment’.

The audit is then compared with the conservation statement noted above, and an access plan can then be developed. An access plan (or access statement) defines what can be done easily, what can be improved, and what the key challenges are to create a fully accessible building. The most common specific challenges are discussed below, although it is outside the scope of this guide to identify all the features of an access audit, as this will cover issues that are unlikely to impinge directly on the requirements of the standard when dealing with conversions. The process is more fully defined in BS ISO 5727: 2024 ‘Accessibility and Usability of the Built Environment -Accessibility of Immoveable Cultural Heritage - Principles and Methodology for Interventions’.

This standard is also intended to prevent the creation of dangerous obstructions or level changes and to provide safe access for maintenance and inspection of the building fabric, for example to allow safe cleaning of windows and to provide safe access to roofs. Most of the requirements are straightforward for new buildings, but the conversion of historic buildings will set challenges for the designer, the most common of which are considered in the following chapters. Existing features may present an inherent risk of accidents that will not occur in new buildings.

As regards safety within traditional buildings, the owners and managers of the buildings as converted should be aware of their obligations under general health and safety regulations, law and policy. Designers and their clients also have wider duties under the Construction (Design and Management) Regulations 2015 (CDM 2015 Regulations). Compliance with this specific standard or advice will not remove or meet these fully. Health and safety in buildings is a complex issue and the Health and Safety Executive has published guidance and codes of practice which are regularly updated and available on their website.

Designers also must ensure that the design of a conversion does not cause unnecessary danger to those who will build, maintain and repair the building. Given the importance of maintenance to the longevity and ongoing condition of any traditional building, it is good practice to enable this to be done safely, even beyond the scope of this regulation. Employers of construction workers that will be working on a conversion and the building’s future maintenance, face increasingly stringent safety guidelines. The opportunity should be taken during a building conversion to improve safe access to all parts of the building to enable the building to be properly altered and maintained in the future.