Red Flags on House Survey. What you need to do.

The importance of a survey when comes to buying a house is still not enough discussed. A survey report can be the deal breaker and without a doubt, we highly recommend getting all possible information before you decide to exchange contracts. If a surveyor’s report brings up any red flags, please do not panic. Here is what you need to do if your report shows any red flags on the house survey.

Waiting for your building survey report can be daunting, especially if you are a first-time buyer. Is natural to be nervous about your survey report as it can reveal that your dream home is actually a nightmare. 

However, do not panic. Can be the case that any red flags on the house survey are actually easy fixes or despite being more serious issues this could be your opportunity to get your dream home at a better price.

In properties, more than 50 years old, is quite common for a building survey to find issues.  An RICS property report has a clear “traffic light” rating system for the condition of different parts of the building. If are any points of concern, ask your surveyor to explain them.

As a note, even the L3 survey (the building survey – the most RICS comprehensive survey) is not an invasive survey. Think of it as a tool you can rely upon to help in getting a general overview of property condition. 

Here are some bad house survey examples; the most common issues a surveyor can come across:

  • Damp – is probably the most common red flag brought up in a survey report. Damp problems can look terrible, but most forms are treatable. We highly recommend getting to the bottom of the cause of dampness, not just treating the symptoms.
  • Subsidence – the most common scenario where subsidence is seen is when the supporting soil moves away from the foundation of the property due to a considerable water leak – a damaged drain.
  • Damage to timber structures – most common causes of timber damage is dry rot or wet rot. 
  • Japanese knotweed – is the most known invasive plant for which treatment can be quite expensive and daunting. There are implications for getting a mortgage and insurance.
  • Foam insulation – probably one of the most discussed topics in recent years is the application of foam insulation either on a roof structure or underfloor one. If foam insulation has been noted within your survey report, we highly recommend considering any implications for getting a mortgage (some lenders would consider that property “unmortgageable“).
  • Outdated property services – the most common red flag highlighted when comes to property services is the outdated wiring system. To rewire an entire property can be disruptive and can cost you thousands.

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Depending on what red flags on the house survey have been brought up, you can discuss what repair work needs to be done with a builder or a specialist tradesperson.

Usually, a building survey will contain an estimation of the repairs, however, we highly recommend getting a second opinion when comes to getting quotations (the best practice is to look for 3 different quotations for each issue).

Once you have an idea of what is going to cost fixing all the issues then you can decide whether the property is worth the asking price or not. With this information, you could:

  1. ask the vendor if they are willing to fix the problems before selling
  2. use the survey report to obtain a better price for the property (usually the new price reflects the costs of fixing all the issues or at least the most serious ones)
  3. proceed with the transaction with an indication of how much extra money you will need to spend on the property once the sale is complete
  4. walk away 

Research from 2016 showed that 60% of homeowners who had a property survey conducted were successfully able to either negotiate a lower price or get the seller to fix the issues before completion. 

Legally, no one is obliged to pay for the problems flagged in the house survey. Normally, the buyer is advised to discuss the repair work with their surveyor or tradesmans to get an general understanding of costs.

As mentioned before, depending on the costs, you can either negotiate the house price down or you ask the seller to fix any issues before completion. Or, you can always walk away if the list of red flags is too long or too expensive for your own budget. 

If the seller is unwilling or unable to fix the problems identified by the survey then you can prepare yourself by getting as much detail as possible on the issues and their outline costs. And of course, you will need to have the additional funds for these repairs.

Having the work carried out post-purchase will give you greater control over the process and the final result. Is just a question of “are you prepared to take on a property that you know needs work?”


As with any cost, it will depend on the nature and the complexity of the problem. We advise looking for at least 3 quotes on each item from specialist contactors. Nevertheless, with an L3 survey (building survey) the surveyor will provide some estimates, such as:

  • Damp – If is a simple to fix issue, such as lack of ventilation within the property, then just a couple of hundreds of pounds on some mechanical fans and dehumidifier will be enough. However, if a chemical damp-proofing is required, this costs around £3,000.
  • Japanese knotweed  – the issue with this invasive plant is that is quite difficult to eradicate it without proper treatment.  The price for professional removal can be around £2,750.
  • Structural movement or subsidence – Some tell-tale signs can include a crack in the ceiling and walls; which usually are bigger than a couple of mm. An average price for fixing typical structural issues is around £15,000.
  • Roof issues – re-tiling an entire roof for a 3 bedroom house can cost around £7,500.
  • Property services issues – To re-wire an entire property can cost around £4,000. To replace drainpipes and damaged drainage can cost around £750.

As per RICS, a seller does not have the right to see a copy of reports unless the buyer chooses to disclose them and the surveyor/valuer must not discuss the report’s actual or likely contents with the seller without the buyer’s knowledge and consent. 

In practice, the seller can stick to his guns and not decrease the price for issues such as dampness (due to lack of adequate ventilation) or partly missing roof insulation.

 However, if your survey uncovers issues that will be costly to fix, it is reasonable to use this as leverage to renegotiate the asking price. 

Our top tips for negotiating a house price are:

  1.  Be prepared – ensure all the repair costs are correct and before presenting them to the seller
  2.  Get expert advice – your surveyor, estate agent, and conveyancer are there to help you with the process and offer professional guidance. We highly recommend getting a local chartered surveyor as your surveyor or to act as a 2nd pair of eyes.
  3. Be willing to compromise – always be realistic about your offer and be prepared for some haggling. Keep in mind that you could be gazumped by someone making a better offer despite all the red flags on house survey.
Written by Danil P.
19th Apr 2022 (Last updated on 30th May 2023)
7 minute read
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