Flood Resilience

What to do if your building is flooded

If your historic building has been flooded, your first priority should be the safety of yourself, your family, and your belongings.

Once it is safe to do so, contact your insurance company. They can provide immediate advice and support.

This guidance outlines some practical steps you can take after a flood and explains when you may need to seek further advice before carrying out repairs or flood resilience works.

When to contact us

You are welcome to contact us at any stage following a flood for informal advice and guidance.

Email the Heritage Team

If significant repairs or alterations are proposed, your insurance company, loss adjuster, or contractor should contact us as early as possible. Providing us with details or an outline of any proposed work can help us to give a better idea of whether consent is necessary, or whether any of the works will need adjustment.

The standard repair methods employed following flooding can sometimes harm the special architectural or historic interest of a listed building, because they are not tailored to their more traditional forms of construction. Early advice can help avoid unnecessary damage and delays.

What issues might occur during the drying process?

Once the flood water has been removed and any debris, mud and dirt cleared, it is important to ensure that the building dries out. Many buildings constructed before 1919 were designed to absorb and release moisture naturally. They were not built to be completely waterproof and often require a different approach to repair after flooding. Therefore, such materials should naturally dry out over time. Nonetheless, providing additional natural ventilation e.g. opening windows, and mechanical ventilation e.g. fans and dehumidifiers, can aid this process. However, care should be taken to avoid drying the building too quickly, or at excessive temperatures, as this can cause further damage, particularly to timber, which is prone to warp. Therefore, it is important to monitor the drying process.

Historic timber floors can be especially vulnerable to flood damage. If you believe your floor has been affected, we recommend seeking advice from the local authority as soon as practicable.

Moisture can become trapped within historic building materials, particularly where modern, impermeable materials such as cement render and gypsum plaster / plasterboard have been added. This can slow the drying process and may lead to:

  • Damp and mould growth
  • Decay of historic materials
  • Rotting timbers
  • Structural damage if left untreated

Where this occurs, it is therefore often best to remove the offending areas of modern impermeable materials as soon as possible. The Heritage Team is therefore generally happy to agree to their removal in principle before Listed Building Consent is secured for it – though Consent may still be required subsequently, subject to the extent of work, and should therefore still be sought as soon as possible. Regardless, it is important to record this work, for example with photographs, should you later need to demonstrate that only modern fabric was removed. Removal should be by hand to limit damage to underlying fabric. If the removal begins to damage historic fabric behind or reveal structural issues (which may pre-date the flood) then the works should stop and further advice should be sought from the Heritage Team and / or a Structural Engineer.

Will I require Listed Building Consent to Repair Flood Damage?

Some historic materials, such as lime plaster, may initially soften, but harden again once dry. It is therefore important to wait until the building is dry before assessing the extent of repair needed.

As for any repair work to a listed building, a certain proportion of repairs, using matching materials, methods and finishes, will not require Listed Building Consent. However, above a certain proportion and / or using non-matching materials, methods and finishes, Consent is likely to be required. The exact point at which the extent of a repair requires Consent will vary somewhat, depending upon the exact significance of the feature in question and nature of alterations.

For works required following a natural event, there would not usually be a requirement to improve upon the previous materials e.g. where modern impermeable materials require replacement. Nonetheless, it would provide a good opportunity to do so as it will benefit the building in the long run.

Do not remove extensive areas of historic flooring, plaster, joinery or other historic features, or carry out structural works, without first discussing the proposal with your insurer, the local authority and, where relevant, a structural engineer experienced with historic buildings. Emergency stabilisation works may be necessary, but permanent repairs to listed buildings often require specialist advice and may require Listed Building Consent. Where temporary stabilisation works are considered necessary, this can often be agreed in writing by the Heritage Team ahead of securing Consent for these, or the final structural works. A photographic record should be undertaken throughout and contact made with the Heritage Team once the stabilisation works are established to ensure they can be agreed ahead of works.

What steps can I take to protect myself from future flooding without requiring Listed Building Consent?

There are several measures that can usually be taken without the need for Listed Building Consent.

Before a flood, it may be helpful to keep:

  • Sandbags or other flood barriers for doors, low-level windows, and air vents
  • A torch or battery-operated light
  • A portable battery pack or power bank
  • Blocks or stands to raise furniture above potential flood levels

The following measures can often be undertaken without Listed Building Consent:

  • Non-return valves on toilets and drainage systems to prevent floodwater backing up into the property
  • Relocating electrical sockets higher up walls to reduce the risk of flood damage and allow power to be restored more quickly
  • Pumps, such as a puddle pump, to help remove water during or after a flood

What steps can be taken with Listed Building Consent?

More substantial flood resilience works may require Listed Building Consent.

Whether such works are acceptable will depend on the significance of the building, the risk of flooding, and the impact of the proposed changes on that significance. Each case is assessed on its own merits.

Possible measures include:

  • Replacing historic air bricks with modern flood-resistant or closable air bricks
  • Installing permanent flood barrier systems at doorways and other openings. Some measures, such as flood gates, may combine permanent fixings alongside a temporary barrier deployed when flooding is likely
  • Removing inappropriate modern impermeable materials, and, as appropriate, replacing them with permeable alternatives, to allow moisture to escape more effectively and reduce the need for extensive wall stripping after a flood. This measure would be supported in principle in almost all cases
  • Raising floor levels

This list is intended to illustrate the types of measures that may be considered, is not definitive, and does not guarantee that consent will be granted.

Other Resources on Flooding and the Historic Environment