How much does damp devalue a house?

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Whether you are selling a house or buying, many things could affect the property’s value. This includes structural issues and cosmetic/decorative issues. Damp can fall into either of these categories depending on its severity. Therefore, damp can definitely affect the value of a property.

How much damp devalues a property, will depend on several factors. These include:

  • The extent of the damp and the damage it has caused.
  • The type of damp (condensation, penetrating damp, or rising damp)
  • How difficult it is to fix.
  • And finally, the cost to fix it.

However, there is good news for sellers.  In the vast majority of cases, dampness is easy to fix and often quite affordable.

how much does damp devalue a house

Condensation is by far the biggest cause of damp and mould in homes. This is caused by a lack of ventilation and air circulation. Solving the issue can be as simple as installing extractor fans in high humidity areas, such as bathrooms and kitchens. Also, things like dehumidifiers, improving insulation and anti-condensation paints can help.

If mould has formed as a result of condensation, this can usually be removed with a simple mould spray and a cloth to wipe down the surface.

The next most common type of damp is penetrating damp. As the name suggests, this is water penetrating from outside the property. If you can identify the cause of penetrating damp, there is a good chance there is a DIY solution or a relatively affordable professional fix.

Finally, the least common, but often the most damaging, is rising damp. However, even rising damp often has DIY solutions, such as injectable DPCs. As well as slurry and epoxy resins that can be applied to floor surfaces such as concrete.

How to stop damp devaluing your house sale

If you are selling a house, then damp can certainly lower its value. This happens because potential buyers will see it as a job that needs fixing after the purchase. This usually means that the value will drop by at least the value of the work.

Another thing to consider is convenience. Many buyers are not looking for a project, most will want to buy their new home and move in. Carrying out work to fix damp problems is likely unappealing to a majority of people.

As a result, you will have a smaller pool of people interested in the property. This can also contribute to a lower market price. It is simply the result of supply and demand.

For general damp issues in a habitable property, the reduction in value will often range between 10-20%.

A property in a poor state of repair. For example, one with extensive structural and cosmetic damage, this number could be far higher. If a property has been neglected for years or even left vacant. Then damp problems can spread and become far more serious. This could include deterioration of structural timbers through rot and even woodworm. There is even the chance of damage to structural masonry, due to spawling and cracked bricks.

In this type of case, a reduction in potential sale price could be significant.

Stop damp affecting your house sale

Damp is very common and as we have already mentioned, there are lots of simple fixes to the majority of issues. This could be installing extractor fans and repairing external defects, such as damaged pointing, bricks, or render. If rising damp is the issue, an injectable DPC can be installed. Most of these can be done as a DIY project, or you can hire a professional.

Once the underlying problem is fixed, you can use a combination of heat, and good ventilation to remove any excess residual moisture present in the surfaces.

What if you don’t know what is causing damp?

If you are unsure what the cause of damp is, then hiring an expert to inspect the property can be a good idea. However, be aware, free surveys from damp companies will often have an ulterior motive. They want to quote you for damp repair work. This means it is very common for them to over quote for more extensive work.

Therefore, it is often better to pay and have an independent surveyor complete a full survey, that includes timber and damp. This will cost you a little bit of money. However, it will identify problems and tell you what needs fixing.

The main thing to remember is even though you will pay out a small amount of money for surveys and repair work. This will usually have a much bigger impact on the asking price.

According to the government house price index, the average house in the UK was worth £277,000 in February 2022. 10-20% discounts due to damp, could mean a significant drop in the money you receive. As a result, rectifying damp issues before a sale is usually recommended.

How to view damp as a buyer

If you are on the other side of the transaction and looking to buy a property, damp is something that can be used as a bargaining tool to potentially reduce the price. This can be particularly true for properties that have been on the market for a while.

Correctly identifying damp, and then resolving the issue with a professional can be expensive. You can factor this into any offer that you make.

You can also factor in the inconvenience and time this may take. For example, if you are not able to live in the property whilst work is being carried out, there are additional expenses to consider. Such as:

  • Mortgage payments for the house whilst you aren’t living there.
  • Rent or other living expenses before moving in.
  • It may hold up other jobs such as decoration that may be needed.

Also, if the property has been on the market for a while, you know you are not competing with a large pool of potential buyers, compared with a home that is ready to move into.

Minor damp issues could allow you to negotiate a good deal on a property. Plus, if you don’t mind getting your hands dirty, it is likely you can fix the majority of problems yourself, as a DIY damp project.


There is no doubt that a property’s value can be affected by damp. However, in reality, the cost and effort to fix most issues are usually quite low, especially for more minor damp issues.

If you are selling a property and want to achieve the best possible price, it is often wise to just bite the bullet and get the repairs done. Simply fixing underlying issues, drying internal surfaces and a little redecoration, can have a significant effect on your potential sale price, so it is usually worth the extra effort.

On the other hand, if you are buying, you can use damp issues to your advantage. Try to figure out the cost implication of work that needs doing. Include all costs and factor this into the offer you make.