How To Protect Your House From Flooding: What Works, What It Costs And What Does Not
A house is protected from flooding by resistance measures that keep water out, such as flood doors, air brick covers and non-return valves, and resilience measures that limit damage when water gets in. Which works depends on the source and depth of flooding.
Check your flood risk band first. Property flood resilience is worth considering from a Medium flood risk band upwards, or where a home has flooded before. Check the flood risk of any UK postcode before spending money.
Partner links on this page are labelled and marked as sponsored. Flood Risk Checker does not install products.
What Is Property Flood Resilience?
Property flood resilience is the set of measures fitted to an individual building to reduce flood damage, as opposed to community defences such as walls and embankments. The Environment Agency's FloodReady review groups it into resistance – keeping as much water out of the property as possible using measures like flood doors and barriers, self-closing air bricks and non-return valves, and recoverability – making internal adaptations, such as having tiled floors, raised electrics and a flood resilient kitchen, so water that does get in causes less harm.
Property flood resilience is most effective particularly in places that experience surface water flooding where the depth of flood water tends to be shallower. Where water is deeper, a building's structure limits how much water can safely be kept out.
GOV.UK lists everyday examples: laying tiles instead of carpets; moving electrical sockets higher up the wall; fitting non-return valves to stop flood water entering your property through the drains; getting flood protection products, for example flood doors or self closing air bricks.
What Is The Difference Between Flood Resistance And Flood Resilience?
Flood resistance keeps water out of a building; flood resilience accepts water will get in and limits the damage. The Environment Agency defines them as: "Flood resistance, or dry proofing, techniques prevent floodwater from entering a building" and "Flood resilience, or wet proofing, accepts that floodwater will enter the building and allows for this situation through careful internal design such as raising electrical sockets and fitting tiled floors."
The choice between them is mostly about depth. Historic England notes that most residential buildings are not structurally capable of preventing floodwater above 600mm, because water pressure can damage walls. For deeper flooding, the Environment Agency's evidence summary says Resilience measure may be suitable for properties vulnerable to repeated flooding where the depth of flooding exceeds 600 mm.
| Resistance (keep water out) | Resilience (recover quickly) | |
|---|---|---|
| Examples | Flood doors, door barriers, air brick covers, non-return valves | Tiled or concrete floors, raised sockets, lime plaster, resilient kitchen |
| Best for | Shallow, short floods | Deeper or longer floods |
| Depth limit | Around 600 mm for most homes without a structural survey | No keep-out limit; water is allowed in |
| Needs action in a flood? | Often — demountable barriers must be fitted | No |
| When to install | Any time | Often during repairs after a flood |
Most homes at real risk need both: resistance for the common shallow floods, resilience for the flood that overtops it.
Which Flood Protection Measures Work For Which Type Of Flooding?
Flood protection measures work differently for each source, because water arrives in different ways: through doors and air bricks from rivers and surface water, up through floors from groundwater, and back through drains from sewers. The matrix below matches measures to sources.
| Measure | Rivers and the sea | Surface water | Groundwater | Sewer backflow |
|---|---|---|---|---|
| Flood doors and barriers | Yes, for shallow depths | Yes — shallow floods suit them | No — water rises through the floor | No |
| Anti-flood air bricks and covers | Yes | Yes | Partly — protects underfloor voids | No |
| Non-return valves | Yes — Historic England notes barriers they will only be effective if the external drainage and internal plumbing are protected by a non-return valve, otherwise water will enter via these routes | Yes | No | Yes |
| Sump pumps | Yes, to remove water that gets in | Yes | Yes — the main measure | Partly |
| Resilient floors, walls, raised electrics | Yes, especially deeper floods | Yes | Yes | Yes |
| Sandbags | Last resort only | Last resort only | No | No |
How each source behaves is explained in surface water flooding, groundwater flooding and coastal flooding.
How Much Does Flood Protection Cost?
Flood protection costs from under £100 for a single air brick cover to over £10,000 for a whole-house scheme with wall treatments. The Environment Agency's cost evidence puts a complete door-gate and air-brick solution at about £2,000 to £4,000, at 2008 prices.
The cost ladder, from the Environment Agency's evidence summary (March 2015, prices from 2007–2008 studies):
| Budget | What it buys | Evidence |
|---|---|---|
| Up to a few hundred pounds | Anti-flood valves: £50–500 (exclusive of labour); aperture guard: £250–750 per guard | EA cost summary |
| Around £1,500–£2,500 | Standard resistance: £1,500 to £2,380 (two demountable door guards and two airbrick covers, residential, 2008 prices) | EA cost summary |
| Around £2,000–£4,500 | Premium resistance: £2,210 to £4,430 (two flood-proof doors, two airbrick covers and external wall render/bricks, residential, 2008 prices) | EA cost summary |
| Around £6,000–£14,000 | Resilient repairs: £6,210 to £9,450 (resilient plaster, removable doors, internal wall rendering, resilient kitchen, raised electrics and appliances, residential, 2008 prices); premium £9,620 to £14,130 (adds concrete or sealed floors, residential, 2008 prices) | EA cost summary |
| £10,000 and above | a complete house solution consisting of door gates and air bricks to protect against flood levels up to 900 mm could cost in the region of £2,000 to £4,000; the former options with anti-flood valves and external wall treatments would be in the region of £10,000 to £14,000 | EA cost summary |
Individual measures, from the same evidence:
| Measure | Cost |
|---|---|
| Flood-resistant door | £875–2,500 per door |
| Air brick covers | £180–1,680 (assumes 12 per property) |
| Automatic air bricks | £1,550 (assumes 12 per property, includes installation) |
| Sump and pump | £50–2,500 (depends on pump capacity and sump size) |
| Free-standing barriers | £5,000–12,000 (free standing barriers for a detached house) |
These are old prices and today's costs will be higher. A 2025 Environment Agency review reported a new-build retrofit of self-closing air bricks, cavity weep vents, sealed service entries and moisture-resistant plasterboard and skirting where The total cost of adding these PFR measures per plot was less than £1,200.
What the same measures are advertised at in 2026. The prices below are the published list prices of named UK suppliers, read on 17 September 2026. They are what a householder pays for the product, and most exclude fitting.
| Measure | 2026 published price | Supplier |
|---|---|---|
| Demountable door barrier | from £495.00 including VAT and mainland UK delivery, rising to £615.00 for the largest door width (119.5–136 cm) | Floodgate |
| Stanchion set for a wide opening | £385.00 for one complete stanchion set, used where an opening is too wide for a single barrier | Floodgate |
| Air brick cover, removable | £30.00 for a single airbrick cover, £60.00 for a double | Floodgate |
| Automatic air brick | £70.00 for an automatic airbrick that closes as water rises | Floodgate |
| Anti-flood air brick | £74.17 plus VAT for an anti-flood airbrick, supply only or supply and installation | Flood Protection Solutions |
| Non-return valve | £70.00 for a universal-fit non-return valve | Floodgate |
Floodgate states: "Prices include VAT, charged at 20%, and delivery". Naming a supplier here is not a recommendation, and none of these links is a paid placement. The National Flood Forum keeps an independent directory of suppliers.
The trade cost guide published by Checkatrade (Last updated: June 2026) gives wider ranges, because it includes fitting: air brick covers where costs start at around £15 and increase to £50+ for more hardcore options, barriers where costs could be around £180+, and internal waterproofing at between £40 and £250 per square metre, with £120 per square metre given as the average.
Every home is different: the Environment Agency notes that The requirements for each property are likely to require bespoke solutions specific to the property. A property flood resilience survey is the way to a reliable price.
Which Measures Actually Reduce An Insurance Premium?
No published rule says which measures reduce a home insurance premium; each insurer decides. The ABI advises owners to Check first if your insurer is able to take surveys into account when assessing whether to insure your property, and certified products with installation records are the evidence insurers can use.
What is known:
- Insurers set their own terms. Prices, excesses and terms for policies are set by insurers and not Flood Re.
- Evidence matters. A property-level survey, product certificates and installation invoices are what an insurer can take into account.
- Certification. Government-funded schemes require that products must have a British Standards Institution (BSI) Kitemark or hold equivalent certification.
- Excess, not only premium. Protection may be more likely to change a flood excess than a premium; see flood excess insurance.
- After a claim. Flood Re's Build Back Better lets insurers pay up to £10,000 towards resilience during repairs, but only around one-third of eligible policyholders accept the BBB offer.
How flood risk affects premiums generally is in flood insurance.
Which Measure Should You Start With?
Filter the measures by the source of flooding you face and roughly what you would spend. The costs are the suppliers' own published 2026 prices, read on 17 September 2026, and they are not a recommendation to buy from anyone.
What The Published Evidence Lets Us Compare
The Environment Agency gives one complete-house example with both a cost and a stated depth: door gates and air bricks designed for flood levels up to 900 mm, at £2,000 to £4,000 in 2008 prices. Dividing that package range by 90 cm gives about £22 to £44 per centimetre of stated resistance.
This is an evidence check for that package, not a quote and not a league table. “Up to 900 mm” is a design limit; a property survey still decides whether a house can safely resist that depth. It must not be used to compare a pump, a valve, or resilient finishes, because those measures do not keep water out to a published height.
Why there is no whole-list cost-per-centimetre ranking. The design brief asked for every measure to be ranked by cost per centimetre. Apart from the complete package above, no source pairs each measure's price with a matching protection height. The costs below are published; the missing ratios are not estimated.
Costs are the suppliers' published prices with VAT and delivery where stated, read 17 Sep 2026, plus the Environment Agency's 2008-price evidence bands for whole-scheme work.
Do Sandbags Work?
Sandbags work poorly: the Environment Agency says sandbags are relatively ineffective when compared to purpose-designed flood protection products, because they leak and take hours to fill and lay. What to use instead, and how to use sandbags if you must, is covered in sandbags.
Can You Get A Grant For Flood Protection?
A government grant for flood protection is usually available only after a named flood event in England, and only to homes that flooded internally in that event. Under the Flood Recovery Framework, Eligible flood-hit property owners will be able to apply for up to £5,000 to help make their homes and businesses more resilient to future flooding via the Property Flood Resilience Repair Grant Scheme.
Two routes exist beyond one-off grants:
- Build Back Better through an insurer using Flood Re, during repairs after a flood claim.
- Community property flood resilience schemes run by councils or the Environment Agency in specific areas.
Who qualifies and how to apply is explained in property flood resilience grant.
Where Do You Start If Your Property Is At Medium Or High Flood Risk?
If your property is at Medium or High flood risk, start by finding out which source and depth of flooding you face, then get a property flood resilience survey, and only then buy products. Buying barriers before knowing how water will enter often leaves gaps.
The order that avoids wasted money:
- Check the band for each source at check the flood risk of any UK postcode. Surface water and river risk need different measures.
- Find out the likely depth. The Environment Agency maps surface water depth bands; ask your council about local flood history.
- Commission a property flood resilience survey from a surveyor trained in the CIRIA Property Flood Resilience Code of Practice. Government schemes require that suppliers must demonstrate competence on the Construction Industry Research and Information Association (CIRIA) PFR Code of Practice by completing training developed by CIWEM.
- Choose certified products. Look for BSI Kitemark certification to BS 851188-1.
- Plan maintenance and deployment. FloodReady found that many people feel that PFR products are "fit and forget", but seals, valves and pumps need regular checks.
- Sign up for flood warnings so demountable measures go in on time.
- Keep records for your insurer and for a future sale.
GOV.UK also points homeowners to the National Flood Forum for advice and to Blue Pages for products. Check permissions too: You may need permission to do work that will affect the flow of a river or divert flood water.
Sources (Verified 17 Sep 2026)
| Claim | Source |
|---|---|
| Resistance and resilience definitions; resilience above 600 mm; cost tables (2007–2008 prices); bespoke solutions | Environment Agency, Cost estimation for household flood resistance and resilience measures (2015) |
| Resistance and recoverability; surface water shallower; Kitemark; CIRIA training; "fit and forget"; BBB uptake; retrofit under £1,200 | Environment Agency, FloodReady review (16 Oct 2025) |
| 600 mm structural limit; barriers need non-return valves | Historic England, Resistance measures |
| Sandbags relatively ineffective | Environment Agency, Sandbags and how to use them properly |
| Everyday measures; National Flood Forum; Blue Pages; permissions | GOV.UK, Prepare for flooding: protect your property |
| Up to £5,000 grant | GOV.UK, Government announces support for flood-hit areas (25 Oct 2023) |
| Surveys | ABI, Accessing flood insurance |
Frequently Asked Questions
What Is The Best Flood Protection For A House?
The best flood protection depends on the source and depth of flooding. For shallow river or surface water flooding, certified flood doors or barriers, air brick covers and non-return valves are the usual combination. For deeper or groundwater flooding, resilience measures and pumps matter more.
How Much Does It Cost To Flood-Proof A House?
Environment Agency evidence puts a complete door and air brick solution at £2,000–£4,000 and fuller schemes at £10,000–£14,000, at 2008 prices. Single products in 2026 are advertised from about £30 to £615, before fitting.
Is Flood Protection Worth It?
Flood protection is most likely to be worth it for homes at Medium or High risk, or that have flooded before, especially where flooding is shallow. For homes at Very Low risk, the cost is unlikely to be justified.
Can Flood Barriers Stop All Flooding?
No. Most homes cannot safely keep out water deeper than about 600 mm without a structural check, barriers leak if drains are not fitted with non-return valves, and groundwater can rise through floors.