CALL US 020 8292 8992
7 DAYS A WEEK 24 HOURS A DAY

Tree survey reports: Don’t apply for planning permission without them

8th April 2021

Share this article

Category

There are many reasons why you might need to apply for planning permission – if you are looking to extend your home or wish to prune or fell a tree that has a Tree Protection Order (TPO) on it, or if it is located in a conservation area. Whatever the reason, it’s well worth understanding what could stand in the way of permission and that’s usually determined by the views of your local planning officer. It is, therefore, often important to support your application with a professional report which evidence, in full, the depth of knowledge held about the trees on your premises and how they may be impacted by the work you want to undertake, in order to give your local planning officer enough reason to say "yes".

Trees can cause local planning officers a significant amount of anguish – they will be concerned about trees that may be impacted by your work or those that may cause damage to new constructions. A risk averse planning officer will always err on the side of caution and, when in doubt, will simply refuse permission. However, it does not have to be that way.

If you think there is any possibility that the trees in and around your property will worry a local planning officer, call in an arborist who can carry out one or more of the following four surveys/investigations and provide reports that could help you to gain the planning permission you’ll need.

  1. BS5837 Tree Survey and Report

This is a superficial assessment of the location, size and condition of any and all trees in the vicinity of the build along with any restrictions placed on those trees (such as TPOs) which could limit your construction work. The report would consist of:

  1. A plan drawing showing where all trees are located, the extent of their crowns and root protection areas (the minimum area required for the roots to grow outwards as the tree matures). 
  2. A table consisting of all the information the arborist has gathered about each tree, including its species, presumed age, condition and life expectancy, to name but a few.
  3. The main body of the report will add context to this data, explaining which are the most important or significant trees in the survey and offering advice on ways to maximise the site’s potential without negative impact on these trees. It may also go into more detail about the maintenance, cutting back or trees to be felled recommendations for the project to proceed.
  • Trial Pit Investigation

If you are considering building an extension to your home, then a trial pit investigation is often a sensible first move. This involves the excavation of a short 3.5m to 4.5m deep trench (either by hand or using a mechanical excavator) to determine a number of things, all related to the structure and content of the soil. If anyone is going to enter the trench, during excavation or as part of the investigation, then beyond 1.2m in depth it will need to be secured to prevent collapse, for obvious health and safety reasons. The purpose of this investigation is to determine the stability of the soil you wish to build on, but it will also reveal whether any tree roots exist within the building zone. Tree roots themselves are unlikely to damage concrete foundations; however, it’s the moisture they suck from the soil that can sometimes have a significant impact on structures – in the form of subsidence, or, if you have recently removed trees, heave (as moisture will build up in soil that would previously have been kept balanced due to the amount of water the tree had taken up).

  • Arboricultural Impact Assessment

Whereas a Trial Pit Investigation is an assessment to determine the impact of trees on a building, an Impact Assessment is an analysis to determine a building project’s impact on the environment around it – specifically the trees in its vicinity. If you are looking to demolish a property, build a new one or, in some circumstances, to significantly extend your property, then it may be sensible to prepare an Impact Assessment report to accompany your planning permission documentation. This could be required for residential or commercial structural or construction work and looks into how the work you’re proposing might impact on the natural world around it. If a local planning authority should consider the impact of a proposed project to be too great then, in the absence of a report to the contrary, a local authority may reject a request for planning permission. A report showing this negative news may still be turned into a positive because its early warning could give you time to amend your building plans to lower their impact and increase your chances of being awarded the planning permission you need to proceed.

  • Basic Tree Survey Report

When all you wish to do is to prune, maintain or fell a tree in a conservation area or one with a TPO, you’ll still need to apply for planning permission. This is when a basic tree survey report would be of use. This report identifies the species of tree, its condition, what work is recommended and why. It’s purely and simply to provide an explanation from a tree specialist as to why work is needed and, therefore, the reason why planning permission should be granted.

All four of these surveys/investigations can be used to help you to maximise your planning permission prospects.

To book a survey and consultation with one of our ARB Approved arborists for advice on your trees or to book our tree surgeons to prune/maintain or fell your tree(s), call us on 0208 292 8992.

Most recent short reads...

8th October 2025
Supporting Greener Communities, Year After Year: Thor's Trees at Islington in Bloom 2025

At Thor's Trees, we believe that thriving communities grow from the ground up - quite literally. That's why, for the second consecutive year, we were proud to sponsor the Tree Pit category at Islington Council's annual gardening competition, 'Islington in Bloom.' Celebrating Community Green Spaces This year's competition was nothing short of inspiring. With nearly […]

Read More
19th August 2025
What Is Tree Surgery and Why Do Trees Need It? 

Trees are remarkably good at looking after themselves - they've been at it for about 370 million years, after all. In wild woodlands, they grow, shed branches naturally, and decay in ways that support entire ecosystems. But here's the thing: the trees in our gardens and streets face challenges their forest cousins never dreamed of. […]

Read More
18th August 2025
Expert Guide to Planting an Olive Tree

There's something rather magical about olive trees in a British garden. Maybe it's the way their silvery leaves catch the light, or how they bring a touch of Mediterranean warmth to our sometimes grey climate. Whatever draws you to them, planting an olive tree is one of those garden decisions you won't regret - as […]

Read More

Why Choose Us

As London’s leading tree surgeons, we promise you will be blown away with our level of expertise and customer care.
24-Hour Emergency Call Out Service
Fully Insured
Free Quotations and Advice
City and Guilds Qualified
Unmatched Workmanship
Our Staff Trained and Qualified to NPTC Standards
crossmenuchevron-down linkedin facebook pinterest youtube rss twitter instagram facebook-blank rss-blank linkedin-blank pinterest youtube twitter instagram