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Impact assessment
An arboricultural impact assessment takes your actual proposals and sets out, tree by tree, what the development will do to them — which are lost, which are retained, what encroaches on their root protection areas and what is done about it.
Typical cost
£345 to £700
assessment and reporting, once a survey exists. The real range, not a headline figure that moves once we have seen the site.
Get a fixed quote →Your quote
One Working Day
A fixed fee in writing within one working day, which does not move once we are on site.
Ask for one →Who writes it
A named consultant
Produced and signed by a qualified arboricultural consultant carrying their own professional indemnity. You get their name before you commit, not after.
Get a fixed quote →The assessment works from an existing BS5837 survey and your proposed layout. It identifies every tree affected by the scheme — removals, pruning, and incursions into root protection areas from foundations, drainage runs, level changes, scaffolding and site access — and quantifies the effect.
It then sets out the mitigation: no-dig construction where a driveway crosses a root zone, hand-dug service trenches, altered foundation design, protective fencing positions, and replacement planting where losses are unavoidable.
Written properly it is the document that turns 'you are building near trees' into 'here is precisely how these trees survive the build', which is the question the planning officer is actually asking.
Tree loss is one of the most common reasons for objection and refusal on small residential schemes. An assessment that shows the losses are justified, the retentions are viable and the replacements are proportionate is frequently the difference between a permission and a refusal.
It is also where an honest consultant earns their fee. We will tell you if a tree cannot survive your scheme, and we will not categorise a healthy category B tree as expendable because a drawing would be easier that way.
Usually yes, once you have a design. The survey establishes the baseline; the assessment tests your proposals against it. Many validation checklists list them separately.
Yes, and it is cheaper that way because the site visit and the base data are shared. Tell us you need both and we will quote the pair.
Then you have found out at the cheapest possible moment. We will set out what would need to change, and in most cases there is a version of the scheme that keeps the trees and the floor area. That conversation is included.
No. The report carries the consultant's name and indemnity, and planning officers read a lot of these. A report that overstates the case is spotted, and it damages the application it was meant to help.
Tell us about the site and we will come back with a fixed fee and a date. No charge for asking, and no charge for being told you need less than you thought.