Guide to Conversion of Traditional Buildings

4.0 Building Definitions

This chapter defines the two principal terms for buildings used in the Guide to Conversion of Traditional Buildings, which are Traditional Building and Listed Building.

The chapter also outlines other historic environment designations that practitioners may need to be aware of when planning a conversion project. This may be because their project is sited within or adjacent to a protected area or structure, or because they may need to demonstrate an awareness of other material considerations when justifying a proposal through a statement of significance.

This chapter also includes an explanation of the way that the term ‘historic building’ is occasionally used in legislation and guidance for planning and building standards.

4.1 Traditional building

The Guide to Conversion of Traditional Buildings is specifically written for those buildings which are traditionally constructed using vapour-permeable natural materials. It recognises that intervention with modern techniques and materials that create barriers to moisture movement may not be compatible with the long-term health of a traditional building’s fabric.

The Scottish House Condition Survey of 2019 identified around 479,000 traditional buildings across the country, accounting for around 19% of Scotland’s total domestic building stock.

a) Definition

The term traditional building is defined as follows:

Traditional building means a building or part of a building of a type constructed

before or around 1919:

a. using construction techniques that were commonly in use before 1919, and

b. with permeable components, in a way that promotes dissipation of moisture from the building fabric.

Traditional buildings are often referred to as having ‘breathable construction’ which means both the materials and the way they are assembled allow for moisture movement away from the fabric through evaporation. This acknowledges the fact that the materials and construction have the ability to absorb and release moisture through a number of mechanisms to keep the interior of the building dry.

These buildings therefore act like an environmental system whereby ventilation of the materials and construction keep both the building and its occupants dry and in good health. More detail on the technical performance of traditional buildings is given in chapter 7 (Understanding Traditional Buildings).

b) Origins of definition

By the 1990s, it was recognised that the application of standards written for new buildings was impacting on the character and performance of buildings of traditional construction.

Historic Scotland created the definition for traditional buildings in recognition of the fact that their vapour permeable construction and materials perform differently to those used in modern construction. Practitioners and verifiers were experiencing difficulties in both meeting the standards and protecting the way that the historic building fabric behaved.

Historic Scotland also recognised that proposals which met the standards were also impacting on the traditional character of Scotland’s older buildings. The term Traditional Building was derived primarily to protect the long term ‘health’ of these buildings when subject to alteration or conversion works. However, the term also recognises that traditional buildings have an inherent cultural value because they are constructed from natural materials sourced and worked by skilled craftspeople using methods developed by and passed down through many generations.

The date of 1919 is not a cut-off date but was identified as a time when the bulk of buildings constructed beforehand would be of traditional construction prior to a significant move over to cavity brick construction in the inter-war period and the greater use of steel and concrete in post-war construction. The date was intended to be helpful in directing those involved in the maintenance, repair, alteration and conversion of Scotland’s building stock and drawing their attention to the likely differences in approach that would be required.

The notional nature of the 1919 date recognises that it is possible to find buildings of conventional traditional construction after this date. It also recognises that modern forms of construction were increasingly adopted across Scotland during the course of the 19th century. Unusual examples include the Waverley Castle Hotel (Scottish Borders), which is a traditional-looking building of 1869 but built in mass concrete, and the Lion Chambers (Glasgow) built in reinforced concrete in 1905.

More typical use of non-traditional materials and construction is likely to be found in factories, offices and school buildings from the second half of the 19th century where historicist designs and stone elevations may mean that their innovative construction is not immediately obvious.

4.2 Listed building

a) Definition

A Listed building is defined as a building of special architectural or historic interest that is included in a List compiled or approved by Historic Environment Scotland as required by the Planning (Listed Buildings and Conservation Areas) (Scotland) Act 1997. Designating a site or place as a listed building recognises its cultural significance at a national level.

To be listed, a building must meet the criteria of special architectural or historic interest as set out in the 1997 Act. To decide if a building is of special interest for listing, Historic Environment Scotland uses selection guidance that examines cultural significance under two main headings:

• Architectural interest – this may include its design, designer, materials, setting and the extent to which these characteristics survive
• Historic interest – this may include a building’s age, rarity, social historical interest and association with people or events that have had a significant impact on Scotland’s cultural heritage.

In this context, buildings are defined as anything made by people such as houses, schools, factories, boundary walls and sculptures.

In Scotland there are approximately 47,000 listed buildings (as at 2026) accounting for less than 1% of Scotland’s building stock. These are classified under one of three categories according to their relative importance. About 7.5% are listed at category A, 49.6% at category B, and the remainder are listed at category C.

It should be recognised that listing is not simply related to age. There are many examples of 20th century buildings, built using contemporary materials and methods of construction, that are listed: the youngest listed building in Scotland is around thirty years old. Buildings younger than this are not normally considered for listing but there can be exceptions.

b) Statutory protection of listed buildings

Listing provides statutory protection to ensure that any changes to listed buildings are given careful consideration through the planning system with a view to preventing unnecessary loss or damage.

The protection afforded by listing covers the whole of a building or structure at the address given, including its exterior, interior, as well as any object or structure fixed to the building. The address of the property is the statutory element. While the listing itself has legal weight, the categories have no legal status and are advisory. Similarly, the information in the listed building record is advisory and helps to identify the building and some of its elements of special architectural or historic interest and forms the basis of how change to a building is managed through the planning system.

Statutory protection may extend to buildings or structures that are not physically attached but which are part of the curtilage (or land) of the listed building, as long as they were erected on or before 1 July 1948. This might include boundary walls, gates, gate piers or ancillary buildings. More information on curtilage listing can be found in chapter 6 (Heritage Management Structure).

A change to the 1997 Act enabled elements or features to be legally excluded from a listing. This means that listed building consent is not required for these areas or structures, unless the works directly affect the listed building itself. This came into effect on 1 October 2015 and the exclusion will be stated in both the statutory address and the statement of special interest in the listed building record. Some earlier listed building records may use the word ‘excluding’, but if the 1997 Act is not quoted, the exclusion carries no legal weight.

Alterations that will affect the character of a listed building require listed building consent from the planning authority. The Act also directs planning authorities, in considering whether to grant planning permission for a development which affects a listed building or its setting, to have special regard to the desirability of preserving the building, or its setting, or any features of special architectural or historic interest which it possesses. Further information on listed building consent and other historic environment consents can be found in chapter 8 (Heritage Management Structure).

More information on the protection of listed buildings and scheduled monuments can be found in Historic Environment Scotland’s Designation Policy and Selection Guidance (2019) on its website.

4.3 Conservation areas

The Planning (Listed Buildings and Conservation Areas (Scotland) Act 1997 directs councils as planning authorities to designate as conservation areas those parts of their district which are identified as having special architectural or historic interest.

There are over 600 conservation areas in Scotland. These can cover historic land, battlefields, public parks or designed landscapes, but most contain groups of buildings extending over areas of a village, town or city.

Under the terms of the 1997 Act, planning authorities are directed to pay special attention to the desirability of preserving or enhancing the character or appearance of conservation areas when considering applications for planning permission. Conservation areas are not only a means of applying increased levels of control to an area of special interest but are one of the measures available to councils in raising the quality of the built environment.

Most works to the exterior of a building or structure within a conservation area will require planning permission. Additional controls may be applied to changes within conservation areas where Article 4 Directions apply, which extends the level of planning control, removing some permitted development rights. These are promoted by the planning authority but usually require approval by Scottish Ministers. Planning permission is normally required for the demolition of buildings within a conservation area.

4.4 Scheduled monuments

Scheduling is the process that identifies, designates and provides statutory protection for monuments of national importance as set out in the Ancient Monuments and Archaeological Areas Act 1979.

Scheduled monuments range from artefact scatters of the earliest peoples to medieval churches and castles to more recent sites such as the remains of 20th-century wartime defences. The law prevents buildings in use as dwelling houses and places of worship from being designated as scheduled monuments although the land beneath them can be scheduled to recognise nationally important archaeological remains.

Once a monument is scheduled, it is an offence to carry out, without the prior written consent (known as scheduled monument consent) of Historic Environment Scotland, any works that would demolish, destroy, damage, remove, repair, alter or add to a monument, or to carry out any flooding or tipping on a scheduled monument. This permission is called scheduled monument consent. Scheduled monument consent is parallel and entirely separate from planning permission – the granting of one does not pre-suppose the need for the other.

Where a scheduled monument has also been designated as a listed building, its scheduling normally takes precedence, although there are some exceptions. This means that scheduled monument consent will normally be needed for works, rather than listed building consent.

A monument is included in the schedule to secure its long-term protection in the national interest, in situ and as far as possible in the form it has come down to us. Works to scheduled monuments should generally be the minimum necessary to preserve their cultural significance, including their current form. Consequently, their restoration is normally not appropriate. Extensive intervention is only permissible where there would be significant public benefits or where it is the best way of preserving its cultural significance. In terms of policy and guidance, including this one, scheduled monuments should not be regarded as buildings. Nor do terms like active use necessarily apply.

When a scheduled monument has been restored for residential purposes the designations would then be reviewed. This may result in the scheduling being removed and the structure being re-designated as a listed building.

More information on scheduled monument consent can be found in chapter 6 (Heritage Management Structure).

4.5 Other historic environment designations

Buildings proposed for conversion may be located in a world heritage site, or within a site that is included in Historic Environment Scotland’s Inventory of Gardens and Designed Landscapes or Inventory of Historic Battlefields. Practitioners should check with the planning authority whether any additional permissions are required for works within these designated areas.

4.6 Historic building

The term historic building previously featured in the Procedural Handbook’s definitions of buildings which were deemed to contribute to Scotland’s cultural heritage on account of their age. Whilst the term is widely used in guidance on managing Scotland’s historic environment, it will be largely phased out of guidance on building standards.

This is because the terms listed building and traditional building have clear definitions that may be a consideration in the application of the standards in certain cases. The term historic building did not have a clearly separate definition that was useful to decision-making in the application of the standards to existing buildings.

It should be noted, however, that the term is occasionally used this guidance in the same way it is loosely used in planning guidance for the wider historic environment to describe an existing building which may be of some age or which may have a greater degree of architectural or historic interest without necessarily being listed.

4.7 Other building standards definitions

Refer to Appendix A Defined terms of the Technical Handbooks for other terms used in the building standards system.

4.8 Further reading

• Scottish Government (2019) Scottish House Condition Survey, 2019
• Planning (Listed Buildings and Conservation Areas) (Scotland) Act 1997
• Historic Environment Scotland (2019) Designation Policy and Selection Guidance
• Ancient Monuments and Archaeological Areas Act 1979
• Scottish Government Building Standards.