Guide
Arboricultural impact assessment: what it is, when you need one, cost
Updated
An arboricultural impact assessment (AIA) sets your proposed layout against the trees a BS5837 survey recorded and says which trees are lost, which are kept and how they are protected. UK consultants publish AIA prices from £200, and it is written after the survey, against your drawings.
What an AIA is
It is one of the reports set out in BS 5837:2012, Trees in relation to design, demolition and construction. The survey records and grades the trees; the impact assessment reads that survey against the plans and sets out the effect of the development on them, including any tree that has to be removed and how retained trees are protected during building.
When the council asks for one
Each planning authority publishes a local validation list saying which documents an application must include (GOV.UK, making an application). Where trees are on or next to the site, many lists ask for a tree survey and an impact assessment together, and an application without them can be returned as invalid. Check your own council's list before you commission either.
What it costs
| Consultant | Published price |
|---|---|
| Godwins | a fee of £200 |
| Arbtech | from £249 |
| Lally Tree Management (full submission with AIA and method statement) | £700 to £1,500+ |
Sources: Godwins, Arbtech and Lally Tree Management. The survey the AIA depends on is priced separately: a median of £349 across 21 consultants (every row).
What to ask
- Is the BS5837 survey included, or does the AIA price assume you already have one?
- Does the price include a tree protection plan and a preliminary method statement?
- How many revisions are included if the layout changes?
Published figures are what each provider advertises on its own page, read through our fetch box on the date shown. A 'from' price is the provider's floor, not the price of your survey.