Heritage Impact Assessment
This section sets out advice on how to produce a Heritage Impact Assessment (HIA) as required under paragraph 189 of the National Planning Policy Framework (NPPF) which states that in determining applications, local planning authorities should require an applicant to describe the significance of any heritage assets affected, including any contribution made by their setting.
This assessment is designed to help local planning authorities make decisions on the impact of proposals for change to heritage assets. This section also considers the need for archaeological desk-based assessments and field evaluations, as well as the relationship of an HIA with Design and Access Statements.
Why is a Heritage Impact Assessment needed?
The Heritage Impact Assessment (HIA) is required in accordance with paragraph 189 of the NPPF. This process is part of a staged approach to decision-making which starts with understanding the significance of the affected assets, before moving on to understanding possible impacts on that significance while avoiding, minimising and mitigating them and pursuing opportunities to better reveal or enhance significance, all therefore leading to the justification for any unavoidable harmful impacts.
When is a Heritage Impact Assessment needed?
A Heritage Impact Assessment (HIA) is needed for any application that directly affects a heritage asset or its setting. A Heritage Impact Assessment will always be required for listed buildings applications, as well as for planning applications proposing the demolition of buildings within a conservation area, and any other new development affecting designated heritage assets such as listed buildings, conservation areas, scheduled monuments, Registered Parks and Gardens and Registered Battlefields.
HIAs should also be submitted for planning applications that directly affect a non-designated heritage asset or its setting, including Local Listings, unregistered parks and gardens and potential areas of archaeological interest which are otherwise not scheduled. Undertaking pre-application discussions with the Planning Department will ensure that heritage assets are identified at the earliest stage.
Assessing significance should come before designing a proposal. The assessment needs to be appropriate and proportionate to the significance of the heritage asset, the impact on that significance and the scope of the proposal.
Heritage assets encompass a wide variety of types. Understanding the significance of heritage assets and the possible impact of a proposed scheme on this significance is the key to good conservation practice. Detailed information on heritage assets and their significance, available from the outset, can speed up the processing of applications, reduce costs and lead to better overall design. If the significance of a site has been clearly understood from the outset (based on how the site has changed through time and what survives today), then both the applicant and the District Planning Authority can better understand the impact of the proposal and seek to minimise the impact of the proposal on that significance. Therefore it is important to understand the significance of a heritage asset when considering proposals to alter, demolish or extend the asset or develop within its setting. An early understanding of the significance will inform the direction of an application and help provide a clear and convincing justification of the proposal.
I already have to include a Design and Access Statement. Do I still need a Heritage Impact Assessment?
Yes. The Heritage Impact Assessment may form part of the Design and Access Statement but the Design and Access Statement is not a substitute for it.
Who should prepare the Heritage Impact Assessment?
The level of detail in the assessment will depend on the heritage asset and the extent of the proposal. The Heritage Impact Assessment should be written by anyone competent to do so. In some cases, this may be the heritage asset owner, but for a complex heritage asset with high levels of significance, it is advisable to employ a heritage professional (i.e. conservation architect, architectural historian or building archaeologist).
If using an architect or agent to submit any application on your behalf, they may also be capable of producing a Heritage Impact Assessment. Independent bodies such as the Register of Architects Accredited in Building Conservation and the Chartered Institute for Archaeologists include a database of suitably qualified professionals.
What should be included in a Heritage Impact Assessment?
In accordance with paragraph 189 of the NPPF, the level of information submitted should be appropriate and proportionate to the significance of the heritage asset and the potential impact of the proposal upon that significance.
For example, for an application that includes substantial demolition of a heritage asset, it is reasonable to expect an applicant to provide a thorough and detailed understanding of the asset and a thorough explanation of the impact of the demolition on the asset and its setting.
An application for a minor alteration to part of the asset is likely only to require detailed information on the affected part of the asset, with only a brief explanation of how the impact relates to the significance of the asset as a whole.
A good set of colour photographs showing the proposal site should be included. There may also be historic photographs of the site, which can often reveal information about how the building has changed and can provide justification for proposed alterations or inform the design of an alteration or extension. Historic photographs can be viewed online via a number of sources, including Picture the Past, Inspire, and locally via local studies archives and our museum resource centre.
Historic map regression can also help in the understanding of the historic layouts of sites and buildings, the relationship with other buildings/structures and surrounding landscapes or gardens. An examination of historic maps may reveal how the site has changed and developed, providing evidence for identifying different building phases.
There are many sources of historic and modern maps, such as enclosure and tithe maps, to the more detailed Ordnance Survey maps which were first drawn in the mid-19th century. The types of maps that you should consult will very much depend on the age of the heritage asset and your proposals, but remember that the amount of research undertaken should be proportionate to the complexity of the proposal. Potential sources include: Insight Mapping, National Library of Scotland and Old Maps Online.
If your proposal site is within a conservation area, the relevant conservation area appraisal document might be a useful source of information.
Paragraph 189 of the NPPF also states that as a minimum, the applicant should consult the relevant Historic Environment Record (HER). The HER will typically include digitised records of archaeological sites and finds, historic buildings, and historic parks and gardens.
The Nottinghamshire HER is managed by Nottinghamshire County Council and can be accessed via the Heritage Gateway which includes spatial depictions of archaeological features, historic buildings, historic parks and gardens, battlefields, scheduled monuments and village cores. The HER is located at County Hall, and the Heritage Team can be contacted via: firstname.lastname@example.org
In addition to the HER, information can be discovered in other external archival sources, such as Nottinghamshire Archives, The National Archives, The British Library, local libraries, The University of Nottingham (Manuscripts and Special Collections) and Trinity College Cambridge (Modern Manuscripts), amongst others.
Heritage asset recording
This section provides a brief summary of the technical aspects of heritage asset recording, including how and when to record heritage assets within the District. There are four levels of recording, ranging from simple photographic records to highly detailed and complex reports.
Why record heritage assets?
The District’s heritage assets, often spanning several hundred years in age, have much to tell us about the lives of past generations, including how people lived and worked, worshipped and spent their leisure time. We can also learn from them how buildings were constructed and adorned, the traditions they embodied and the aspirations they expressed. They are a living record of our social, economic and artistic history, as well as being powerful contributors to our sense of place and to feelings of local, regional and national identity.
The term heritage asset is defined in Annex 2 of the National Planning Policy Framework (NPPF) as a building, monument, site, place, area or landscape identified as having a degree of significance meriting consideration in planning decisions, because of its heritage interest. Heritage asset includes designated heritage assets and assets identified by the local planning authority (including local listing).
When is heritage asset recording required?
The local planning authority might request heritage asset analysis and recording during pre-application discussions with a developer, perhaps in order to better understand the significance of the asset, including its condition and structural complexity. Recording is also necessary when a condition is attached to a relevant planning permission or listed building consent in accordance with government advice. Paragraph 199 of the NPPF states: “Local planning authorities should require developers to record and advance understanding of the significance of any heritage assets to be lost (wholly or in part) in a manner proportionate to their importance and the impact, and to make this evidence (and any archive generated) publicly accessible. However, the ability to record evidence of our past should not be a factor in deciding whether such loss should be permitted”.
How to record heritage assets
It is expected that the recording of heritage assets will follow available professional standards and guidance such as the Chartered Institute for Archaeologists. The most commonly referred to guidance is the Royal Commission of the Historical Monuments of England (RCHME) advice note ‘Recording Historic Buildings’ (1996). This guidance has been revised and expanded by Historic England in their publication Understanding Historic Buildings – a guide to good recording practice (2016). These documents define 4 levels of building recording that are frequently used in conditions attached to Planning Permissions and Listed Building Consents.
At one end of the spectrum, Level 1 recording is very simple and requires only a basic level of recording, whilst Level 4 represents the greatest complexity of recording and analysis. Each level corresponds to a minimum specification, from photography to technical drawings and building analysis. Additional bespoke recording elements may be added by the local planning authority depending on the complexity or nature of the asset to be recorded (this may, for example, allow for detailed analysis of particular features and architectural elements).
Fundamentally, the recording level specified will depend on both the significance of the building and the purpose for which the record is intended. The recording method should not involve unnecessary work, and should be the minimum necessary to achieve the recording objectives.
Heritage assets and building regulations
The building regulations set standards for design and construction for the purposes of securing reasonable standards of access, health and safety. The regulations apply to most new buildings, as well as many alterations to existing buildings, including listed buildings.
The building regulations only apply to new work and there is no general requirement to upgrade all existing buildings to meet these standards. Where a building did not comply with the regulations before the alteration, the proposals should be undertaken so that when complete, the building's compliance with the Regulations is ideally improved, but at least, not worse.
Heat efficiency and thermal improvements
Part L of the regulations deals with the conservation of fuel and power. Listed buildings, buildings within a conservation area or scheduled monuments are exempt from compliance with the energy efficiency requirements of this part insofar as where it can be demonstrated that the requirements would unacceptably alter the character or appearance of such buildings.
Separately, the following buildings are also subject to special consideration under part L:
- Local interest buildings of architectural or historic interest
- Buildings of architectural or historic interest whether locally-listed or not that are within Registered Parks and Gardens and Battlefields, and the curtilage of designated heritage assets
- Buildings of traditional construction with permeable fabric that both absorbs and readily allows the evaporation of moisture (which can conflict with modern materials and methods).
The aim for these buildings should be to improve energy efficiency as far as is reasonably practicable without prejudicing the character of the building or increasing the risk of long-term deterioration.
Building Regulations compliance is monitored and certified by officers East Midlands Buiding Control. Their advice should be sought when planning works as to what Regulations will apply and what procedures to follow. Alternatively, there are accredited professionals who can provide Building Regulations approved on a 'self-certification' basis.
Listed buildings and alterations required to comply with building regulations
If you are contemplating works required under the building regulations, we suggest that you seek advice from our Conservation Team in order to discuss the implications for impact on the special interest of the building, and the need for any authorisation from the local planning authority.
In the situation that consent has already been sought, please note that amendments to any approved planning and listed building consent applications hereby permitted that may be necessary to comply with the building regulations must also be approved in writing by the Local Planning Authority in order that any planning implications arising from those amendments may be properly considered.
Window improvements and thermal upgrading is a commonly requested in listed buildings. The detailed Historic England guidance on Traditional Windows: Their care, repair and upgrading (2017) provides useful guidance on when and how this might be acceptable. In applying their guidance, the evidential, historical and aesthetic values of the existing windows must be considered when considering improvements to joinery in terms of their construction, specification and appearance.
An application for approval of details reserved by condition will be necessary where a condition in a planning permission or a listed building consent requires details of a specified aspect of the development (which was not fully described in the original application) to be approved by the local planning authority before the development can begin.
An application for approval of details reserved by condition should only follow the previous granting of planning permission or listed building consent, and cannot be used as a ‘standalone’ application for works requiring planning permission or listed building consent.
This process is known as discharging conditions. The application is available on the Planning Portal.
It is important to understand precisely what a planning permission or listed building consent actually gives permission for. Furthermore, failure to comply with a condition attached to a listed building consent, whereby such works materially affect the special historic or architectural significance of the building, is a criminal offence.
If in doubt, please contact the conservation team for advice on the discharge of condition process.
Newark and Sherwood District Council
Phone: 01636 650000
Nottinghamshire County Council
Phone: 0300 500 80 80
Historic England (Midlands Office)
Phone 0121 625 6888