Mould in a New Build House – What Can I Legally Do?

Unfortunately, mould and damp aren’t just a problem for older houses. They can appear in new builds for a variety of reasons.

If your newly built home is showing signs of mould and condensation, it’s best to find out the cause and deal with it fast. In this guide, we’ll cover what to look for, who to contact, and your legal options if something is wrong with your house’s construction.

What can cause mould in a new build?

Mould is caused by excess moisture and humidity in your home. Here are some of the ways a new build can develop a mould problem.

1. Moisture from construction

Believe it or not, construction is a wet process, especially if materials are exposed to rain before being sealed. Materials like timber, drywall, and concrete can all absorb rain or high humidity. If moisture is trapped during the building process, this can develop into mould.

2. Poor ventilation and airflow

New builds are often designed to be energy-efficient. This can help prevent draughts and keep warmth in, but has the added effect of limiting natural airflow. If your new build bathroom, kitchen, or attic has little access to fresh air, it may be prone to humidity and mould.

3. Building or plumbing problems

Construction defects, like poorly installed windows, gutters or roofs, can allow water to seep into the home. This makes a perfect environment for penetrating damp and mould to develop. Plumbing issues can also create persistent dampness ideal for mould.

4. High humidity or low insulation

Homes with high humidity or little insulation can be prone to condensation, especially where warm and moist air meets cold surfaces. Moisture can collect on floors, ceilings, and walls, leading to mould. However, many new builds are adequately insulated and warm.

If any of the above sounds like it might be happening in your new build home, keep a close eye on the below signs of mould.

Signs to look out for

Even in new builds, mould can develop if the conditions are right. It’s important to catch it early before it spreads throughout your home. Mould isn’t visible in its early stages, but there are other indicators – such as odours or health symptoms – that may suggest problems.

• Condensation – excessive moisture building up on walls or pipes, particularly in bathrooms with poor ventilation
• Musty smells – an unusual, damp odour can be the first sign of a mould problem, even before visible signs appear
• Peeling paint – ceilings or walls with bubbling paint can show trapped moisture, which can indicate a damp problem
• Health issues – respiratory issues or allergic reactions could be a sign of mould, especially if they improve outside
• Water stains – tidemarks or stains on walls could be a sign of a leak, which may in turn develop into a mould issue
• Discolouration – dark or discoloured patches, particularly around windows or in corners, could be a sign of mould

Not all mould looks the same or is immediately obvious, so it can help to look at examples or book a free property survey. Our Surveyors can use instruments to check a new build for issues, including surface temperature gauges and hygrometers, which measure humidity.

But if you discover mould in your new build, what can you do about it? Here are some actions you can take to resolve the issue.

Contact the builder

Early and open communication with your builder or developer is essential, as they may be able to help put things right post-build.

Your new build may have a time-sensitive guarantee or warranty, so get in touch about your concerns as early as possible. The builder may be responsible for addressing moisture issues related to the house’s ventilation or structural integrity, or problems during its construction.

Construction is a wet process, it can take a long time for a new build to dry out, particularly if there is rain during the build.

“For example, you spot mould growth a few weeks after moving into a new build. After you contact your builder, they carry out an inspection and find the bathroom’s ventilation system was not correctly installed. Because you acted quickly, and the new house is still under warranty, the builder may agree to fix the ventilation issues. They may even help you contact a condensation specialist to deal with the resulting damage.”

It may seem like you’re bothering them, but it’s best to get in touch. A mould problem could cost you a lot of money down the line.

Know your legal rights

When dealing with mould in a new build, it’s important to know your rights. This can help to avoid costly repairs down the line.

• Check whether your new build has a guarantee within the contract, covering structural defects or damp issues
• Research laws regarding mould and construction defects, and whether your builder is required to fix them by law
• Keep thorough documentation of communications with the builder, and photograph evidence of mould issues
• If the builder doesn’t take your claim seriously, consider hiring an independent professional to inspect the property
• Hiring a lawyer specialising in construction defects or housing law may help guide you through the process
• Keep thorough documentation of communications with the builder, and photograph evidence of mould issues
• If the builder doesn’t take your claim seriously, consider hiring an independent professional to inspect the property
• Hiring a lawyer specialising in construction defects or housing law may help guide you through the process

Getting advice can help you determine whether you have grounds for legal action and what support you’re entitled to.

Hire a damp surveyor

If mould is a recurring problem in your new build home, it may be a good idea to hire a damp Surveyor for an inspection.

At Allerton Damp, we can visit your property and do an inspection, helping to find the cause of mould or damp. We can provide an independent report, showing the extent of the issues and recommended actions, which can help if you’re working with your builder.

Our Surveyors are experts in the detection and prevention of condensation. They have access to advanced instruments to use during their damp proofing survey such as laser surface temperature gauges, hygrometers, and damp meters; with such tools, our Surveyors can say for certain whether a home suffers from condensation. We can also give recommendations for how to fix issues and implement these.

Book a Free Property Survey

Remove mould safely

To address mild mould issues yourself, ventilate the area and open windows before you start using DIY mould-removal products. While wearing protective gear, you can clean the visible mould area with mould-removal spray and wipe down non-porous areas with a cloth.

However, this does not address the root cause and without tackling this, your mould and condensation issues are likely to return.

We recommend an inspection from a specialist, as they know which products are best for the situation. These could include installing an extractor fan, adding a thermal coat to help prevent ‘sweating’ walls, or waterproofing external brickwork to avoid water ingress.

How to prevent mould in new builds

The best way to avoid future mould issues in your new build is to keep your home warm, ventilated and dry. Here are some helpful tips:

• Keep your home ventilated by opening windows regularly, especially in humid rooms like kitchens or bathrooms
• If you can’t open a window, ensure the room has an extractor fan fitted to remove steam from showers or cooking
• Check your home’s humidity with a meter – running a dehumidifier can help keep humidity levels under 60%
• Regularly check for plumbing or gutter issues, as these can cause water and moisture to seep into your home
• Maintain a stable indoor temperature to help prevent condensation, by using your central heating appropriately

By following these practical tips, you can help keep your new build home mould and damp-free for many years to come!

Dealing with mould in a new build can be frustrating, but taking early action is the key. Contact your builder, research your rights, and document any ongoing moisture problems. Good luck in resolving any damp issues and enjoying a safe, comfortable new home.

Questions? Contact Us