Property Flood Resilience Code of Practice

Although Historic England supports the CoP, it has identified where further guidance is required, and this webpage seeks to fill that void to ensure that the historic interest of a building is considered as early as possible.

Following these additional standards should prevent project delays, ensure consents are acquired prior to works commencing, and make sure that options are proposed based on a thorough and proportionate understanding of a building's significance.

Standard 0: Assessment of Significance

Working with local authorities

Historic England recommends a proposed new standard that should be undertaken at the commencement of a project.

Heritage properties at risk of flooding should be identified early on in the project, to facilitate early engagement with the local authority and prevent delays.

Identifying the listing types is important, as the higher the status of the listing, the greater the impact of proposed changes on the significance of the building. A Grade I listing is likely to require a more considered approach and a more detailed options analysis than a Grade II listing.

Information gathered about the historic building should be used to inform the options appraisal and support in finalising appropriate flood mitigation measures.

Engagement with the local authority should consist of explaining the project outcomes, establishing an expected timeframe and identifying how the local authority would like to be kept informed and the extent of listed building consent applications expected. Early engagement could identify that individual applications may not be appropriate, and instead collaboration with the local authority to create a design guide or agree a Local Listed Building Consent Order (LLBCO) may be more suitable.

It is not considered best practice to wait until Standard 3: Options Development and Design to consult the appropriate authorities. It is also worth asking the local authority if it is acceptable to put in an application without the full details. For example, where it is known that lime mortar will be used, it may be possible for the conservation officer to sign off a sample on site at a later date once the exact mix has been established.

Why understanding significance is important

Identifying the listing status of a building and understanding its significance may highlight immediately if certain design options are going to be inappropriate, either from a structural point of view or because they will harm the building’s heritage. For example, if the front door is specifically mentioned in the listing, then it is very unlikely that consent will be given to replace the door. Thus, by the time Standard 3: Options Development and Design is in progress, it will already be known that some options are not viable.

Understanding the listing status of the building and its significance will help with consideration of different options and producing evidence for the local authority as to why they were discounted. Proposed works should look to minimise the impact on the building fabric, and the information gathered will help support any heritage impact statements that need to be submitted later in the project.

Every assessment and impact statement should acknowledge the effect flooding will have on the building fabric if no PFR or adaptation measures are put in place. If a building is subject to continuous wetting and drying, the fabric will decay and historic fabric will be lost. This is likely to be more significant where a building is at risk of frequent flooding (in one year) or where it is by the coast and subject to raised salination levels.

Measures to protect a building or make it more resilient to flooding should not be refused on the basis of its listing. Flooding may cause significantly more harm to a building than the proposed measures to make it more resistant. Assessing and addressing the impact of flood resilience measures versus the potential loss of historic fabric or significance needs to be proportionate.

Standard 3: Options Development and Design

Historic England proposes that Standard 3 should cover the topic of consents.

At present, the CoP mentions best practice in standards, guidance and compliance with the Construction (Design and Management) Regulations 2015, but does not explicitly mention consents for listed buildings and those in conservation areas.

As previously discussed, early engagement is key to prevent a project being delayed. But it is also a legal requirement that consents are in place prior to work being undertaken. LBC applications are there to ensure that historic buildings are not damaged by inappropriate works. Applications that can explain why the proposed work is the most desirable or only option are more likely to be successful.

The following are key to identifying appropriate measures:

• a proper understanding of what makes the building significant
• a clear understanding of the limitations that the building’s significance presents
• the extent of decay and loss to the building if no works are undertaken and a flood occurs
• the point at which increased maintenance is not adequate and change is required

Additional advice on appropriate measures can be sought from a professional such as an architect, surveyor or structural engineer who is conservation accredited, or has experience of repairing and adapting older buildings.

It is important to identify which measures are appropriate because many – such as damp-proofing systems, tanking and hard cement renders – are not suitable for buildings of traditional construction as they impede their natural ability to manage water liquid and vapour. Other options may not be appropriate because of their high impact on a building's significance.