Buying a New Build Near Trees? Here's What You Need to Know
When you're viewing a new build property with mature trees nearby or attractive hedgerows along the boundary, it's easy to focus on the aesthetic appeal. However, trees and shrubs near your new home can have significant implications for the building's foundations, particularly in areas with clay or other shrinkable soils. Understanding the NHBC guidelines on building near trees can help you ask the right questions and ensure your new home has been built to the correct standards.
Why Trees Matter When Building on Shrinkable Soils
Many areas across the UK have what's known as shrinkable soils, typically clay-based ground that contains more than 35% fine particles. These soils undergo volume changes as their moisture content fluctuates. Trees, hedgerows and shrubs naturally extract moisture from the soil through their root systems, which causes the ground to shrink during dry periods. Conversely, when trees are removed or during wetter periods, the soil can swell or "heave" as moisture returns.
For your new build home, this creates two potential problems. Firstly, the soil shrinkage can cause subsidence, where the ground beneath the foundations moves downwards. Secondly, ground heave can push upwards on foundations and floor slabs. Both scenarios can lead to cracking in walls, misaligned doors and windows, and in severe cases, significant damage requiring expensive remedial work.
What the NHBC Guidelines Require
Chapter 4.2 of the NHBC Standards provides detailed guidance for builders constructing homes near trees, and compliance with these requirements is mandatory for all NHBC-registered developments. The guidelines address several critical aspects that directly affect the quality and safety of your new home.
The foundation design must account for the species of nearby trees, their mature height, and their water demand. For example, oak and willow trees have particularly high water demands and can affect soil moisture at greater distances than other species. The foundation depth must be sufficient to reach below the zone of influence where tree roots can cause problematic ground movement. In some cases, this might mean foundations extending to 2.5 metres or deeper, depending on the size and type of trees present.
The guidelines also require builders to provide detailed site plans showing the location and species of all existing and proposed trees. Before construction begins, a thorough survey should record the position, height and species of trees and hedgerows. If trees have been removed from the site historically, the builder should have investigated this through local enquiries or aerial photographs, as the effects of removed trees can persist in the soil for many years.
Different foundation types may be required depending on the site conditions. Strip foundations, trench fill, pier and beam, pile and beam, or raft foundations might all be appropriate, provided they're correctly designed for the specific combination of soil type and tree influence. Importantly, heave precautions must be incorporated, which might include using compressible materials or void formers beneath ground floor slabs to accommodate any upward ground movement.
What This Means for Your Inspection
When Brickkickers conducts a pre-completion or standard snagging inspection on your new build home, we're looking for evidence that these guidelines have been properly followed. Whilst we cannot see beneath the ground to inspect the foundations directly, there are tell-tale signs that can indicate potential issues.
Cracking in external brickwork, particularly diagonal cracks near corners or around windows and doors, can suggest foundation movement. Internal wall cracks, especially those wider at the top than the bottom, may indicate settlement. Doors and windows that don't close properly or have uneven gaps around the frames can also point to ground movement affecting the building's frame.
We also examine whether adequate drainage has been installed to cope with potential ground movement, as the NHBC guidelines require steeper gradients in areas affected by trees. Our thermal imaging technology can identify unusual heat patterns that might suggest problems with ground floor insulation or floor slab positioning.
Questions to Ask Your Builder
Armed with knowledge of the NHBC requirements, you can ask your builder informed questions about how they've addressed trees on or near your plot. Don't be afraid to request information about the foundation type and depth used for your specific home. Ask whether a specialist arboricultural survey was conducted and what measures were taken to protect retained trees during construction.
If trees were removed from your plot or nearby before construction began, find out what species they were and when they were removed. The soil may still be recovering moisture following tree removal, which can cause heave for several years afterwards. Your builder should be able to explain what precautions were incorporated into the foundation design to address this.
Why a Professional Snagging Inspection Matters
With nearly 20 years of experience in new build snagging services, Brickkickers has inspected thousands of properties across the UK. Our data shows that the average new home has in excess of 140 defects, many of which aren't immediately obvious to homeowners. Issues related to foundations and ground movement are among the most serious, as they can worsen over time and become increasingly expensive to remedy.
Our nationwide network of experienced construction professionals understands the requirements of NHBC and all other warranty providers. We know what to look for and, crucially, how to present our findings in a way that ensures builders take their responsibilities seriously. Whether you're arranging a pre-completion inspection before you legally complete, or a standard snagging inspection after you've moved in, our detailed reports give you the evidence and support you need to get defects rectified under warranty.
For properties where there are concerns about foundations, trees or ground conditions, we also offer customised and intrusive building surveys. These go beyond standard snagging inspections and can include opening up parts of the property to investigate specific issues. This service is particularly valuable if you're experiencing ongoing problems or are in dispute with your builder about the quality of work.
The Long-Term View
Remember that trees continue to grow after your home is built. A young tree planted as part of the landscaping might seem insignificant now, but could have a considerable impact in 10 or 20 years' time. The NHBC guidelines require builders to consider the future growth of young trees when designing foundations, so adequate provision should already be in place.
Similarly, if large trees near your property are removed in the future, perhaps because they're diseased or dangerous, this removal can trigger ground heave as moisture returns to the soil. Understanding these long-term dynamics helps you make informed decisions about tree management on your property and recognise when professional advice might be needed.
Protecting Your Investment
Your new build home represents a significant investment, and ensuring it's been built to the correct standards is vital for your peace of mind and financial protection. The NHBC guidelines on building near trees exist to protect homeowners like you from the serious problems that can arise when foundations aren't properly designed for site conditions.
A professional snagging inspection from Brickkickers provides independent verification that your home meets the quality standards you've paid for. We're here to represent your interests, not the builder's, and our detailed reports ensure any defects are identified and rectified before they become your problem.
If you're buying a new build property, particularly one with trees nearby or on clay soil, don't leave things to chance. Contact Brickkickers on 0845 226 6036 or email info@brickkickers.co.uk to arrange your pre-completion or standard snagging inspection. With our expertise, you can be confident you're getting the quality home you deserve.