Hedgerows: the 1997 Regulations and biodiversity units
Two regimes govern hedgerow removal and they run on different clocks. This explains the removal notice procedure, the important hedgerow criteria and how hedgerow units behave in the statutory biodiversity metric.
Removing a countryside hedgerow now engages two separate regimes that do not talk to each other. The Hedgerows Regulations 1997 control whether you may take it out at all, through a removal notice served on the council. The statutory biodiversity metric controls what you have to put back, in hedgerow units, and those units cannot be replaced with anything else. Getting permission under the first and ignoring the second is a common and expensive mistake on small rural sites.
Hedgerow units trade only against hedgerow units. That single rule shapes most site layouts once you understand it.
What the Hedgerow Regulations 1997 protect
The Regulations apply to hedgerows of 20m or more in length, and to shorter hedgerows that meet another hedgerow at each end, where they grow on or next to agricultural land, common land, village greens, sites of special scientific interest, local nature reserves or land used for forestry or the keeping of horses.
Garden hedges are outside the regime. A hedgerow within the curtilage of a dwelling, or marking its boundary, is excluded, which is why a suburban boundary hedge attracts no protection under these Regulations at all.
Removing a protected hedgerow without following the procedure is a criminal offence, and the court can order replanting on top of the fine. The full criteria and the exemptions are set out in our guide to important hedgerows under the Hedgerows Regulations 1997.
Separately, the Management of Hedgerows (England) Regulations 2024 reinstated the cutting ban between 1 March and 31 August and the buffer strip requirement on agricultural land, enforced by the Rural Payments Agency rather than the planning authority. Check the current position before scheduling any cutting, since the two regimes have different exemptions.
The important hedgerow criteria and how they are tested
A hedgerow is "important" only if it has existed for 30 years or more and meets at least one criterion in the archaeological and historical group or the wildlife and landscape group in Schedule 1.
The historical criteria look at parish and manor boundaries, integrality with a pre-1845 field system, association with a scheduled monument or a recorded archaeological site. Proving them is a map exercise: tithe maps, enclosure awards, the first edition Ordnance Survey, and the Historic Environment Record.
The wildlife criteria are botanical and structural. Woody species counts along a 30m sample length, the presence of associated features such as a bank, ditch, wall or tree line, and connectivity to woodland or other hedgerows all feed in. Counts are taken from a defined number of sample lengths, and the threshold varies by region.
Assessing this properly takes a botanist in the growing season. An assessment carried out in January, from the road, will be challenged.
Serving a hedgerow removal notice and the response period
The procedure itself is short and strict.
- Complete a hedgerow removal notice giving the location, a plan showing the hedgerow, the length to be removed and the reason for removal.
- Send it to the local planning authority with evidence of how long the hedgerow has existed.
- Wait. The authority has 42 days from receipt to respond.
- If the authority serves a hedgerow retention notice, the hedgerow must stay and there is a right of appeal to the magistrates' court.
- If the authority states in writing that it has no objection, or if 42 days pass with no response, removal may proceed within the following two years.
Regulation 6 lists the circumstances where no notice is needed, including removal to make a new opening in place of an existing one, removal for national defence, work by a drainage body, and removal to implement a planning permission that has already been granted. That last exemption is the one that matters most on development sites, and it is why the sequencing of hedgerow work against the grant of permission is worth thinking about early.
How hedgerows are measured in the statutory metric
The statutory biodiversity metric splits habitats into three modules: area habitats measured in hectares, hedgerows measured in kilometres of length, and watercourses measured in kilometres. Each module produces its own units, and the 10 per cent net gain requirement under the Environment Act 2021 applies to each module separately where that module is present on the baseline.
The trading rules then bite. Hedgerow units lost must be compensated with hedgerow units, either on site or off site. Creating a wildflower meadow does not offset a lost hedge, no matter how many area units it generates.
Distinctiveness bands within the hedgerow module reflect what the hedge actually is. A species-poor line of hawthorn scores lower than a native species-rich hedgerow, and a hedgerow associated with a bank or ditch, or with mature trees in it, scores higher again. A Biodiversity Net Gain Assessment for a site with hedgerows should record each of those features separately, because they change the baseline materially.
The metric must be completed by a competent person under the Environment Act 2021 regime, and the biodiversity gain plan is approved by the local planning authority after permission is granted. An AI-assisted draft can structure the narrative and the policy references, but the metric calculation itself is professional work.
Condition assessment and what improves a score
Condition is scored against a set of criteria covering height and width, gaps along the run, continuity of the canopy, density at the base, the presence of undisturbed ground alongside, and the extent of nutrient-loving or invasive species. The result is good, moderate or poor, and it multiplies the distinctiveness score.
The practical consequence is that a neglected, gappy hedge on a site baseline generates few units, which makes the 10 per cent easier to meet. A well-managed species-rich hedgerow with mature trees generates many, which makes removal very hard to compensate.
Condition also gives you the least costly route to a gain. Taking an existing poor-condition hedgerow to moderate or good through gapping up, reduced cutting frequency and a wider uncultivated margin produces units without acquiring any land. It is slower than planting, because the metric applies a time-to-target-condition delay, but it is usually deliverable within the site boundary.
An illustrative example
A paddock site of about 0.4 hectares with 180m of species-poor, heavily flailed hedgerow along two boundaries, of which 25m is to be removed for an access. The baseline scores poorly because of condition. The scheme retains 155m, gaps up the retained runs with native whips, widens the margin to 2m and plants 40m of new native hedgerow along a new boundary. The hedgerow module reaches the required gain within the site, and no off-site units are bought. This example is illustrative rather than drawn from a specific case.
Gapping up, laying and creating new hedgerows
Three interventions do most of the work, and they behave differently in the metric.
| Intervention | Effect in the metric | Practical note |
|---|---|---|
| Gapping up existing runs | Condition improvement on retained length | Fastest route to a gain, no new land needed |
| Hedge laying or coppicing | Condition improvement over time | Short-term appearance is poor, so explain it to the case officer |
| Planting new hedgerow | New units, with a time penalty | Needs 30-year management and a secured maintenance regime |
| Adding trees within a hedge | Moves to a higher distinctiveness type | Depends on achieving the required density at maturity |
Whichever route you take, the 30-year management commitment applies. That is secured by a planning condition or a section 106 obligation, and the maintenance schedule needs to be specific about cutting frequency, cutting height and the months in which work may take place.
Where planning permission and the Regulations overlap
The two regimes run on different clocks, and that is where projects come unstuck.
If you have planning permission that expressly authorises the removal, the 1997 Regulations exemption applies and no removal notice is needed. If you do not yet have permission, and you remove the hedge to tidy the site before submitting, you have probably committed an offence and you have also destroyed your own baseline. Deliberate damage before survey does not reduce the biodiversity baseline, because the metric is assessed on the habitat that was there.
Where a hedgerow supports nesting birds, dormice or a commuting route for bats, protected species law applies independently of both regimes. A Preliminary Ecological Appraisal should identify that before any clearance is programmed, and a licensed ecologist is legally required for protected species work.
Order the work in this sequence: survey in the growing season, assess age and importance from historic maps, run the metric baseline, design the layout around retention, then serve any removal notice or rely on the permission exemption. Doing it in any other order usually costs more.
Enter your postcode on PlanScope to see which reports your site is likely to need, then browse the report types by category before you commission anything. This is general guidance, not legal advice. Check the position with your local planning authority or a qualified professional before relying on it. PlanScope provides AI-assisted draft reports for planning applications. Reports should be reviewed before submission. We do not guarantee planning approval.
Frequently asked questions
Does the Hedgerows Regulations 1997 procedure apply to my garden hedge?
No. A hedgerow within the curtilage of a dwelling, or marking a boundary of that curtilage, is excluded from the Regulations. They apply to hedgerows of 20 metres or more, or shorter runs meeting another hedgerow at each end, on or next to agricultural land, common land, village greens, sites of special scientific interest, local nature reserves, forestry land or land used for keeping horses.
How long does the council have to respond to a hedgerow removal notice?
Forty-two days from receipt. If the authority serves a hedgerow retention notice within that period, the hedgerow must stay and you can appeal to the magistrates' court. If it confirms no objection, or the 42 days pass without a response, removal may go ahead within the next two years. Keep proof of the date the notice was received.
Can I offset lost hedgerow with new woodland or grassland?
No. The statutory biodiversity metric treats hedgerows as a separate module from area habitats and watercourses, and the trading rules require hedgerow units to be replaced with hedgerow units. Creating grassland or woodland generates area units that cannot compensate a hedgerow loss, so the layout usually has to find hedgerow length somewhere on or off the site.
What makes a hedgerow important under the Regulations?
It must have existed for 30 years or more and meet at least one criterion in Schedule 1. The historical criteria cover parish or manor boundaries, integrality with a pre-1845 field system and association with archaeology. The wildlife and landscape criteria look at woody species counts in sample lengths, associated banks, ditches, walls and tree lines, and connectivity to woodland.
Does clearing a hedge before survey reduce my biodiversity obligation?
No, and it makes matters worse. Deliberate degradation before assessment is dealt with by assessing the baseline as it was, so the units still have to be replaced. Removal without a notice where one was required is a criminal offence in its own right, and the court can order replanting in addition to a fine.
Sources and further reading
This article is general guidance about the planning system in England and, where stated, the rest of the UK. It is not legal or professional advice. Check your local planning authority’s validation requirements and take professional advice for your specific site.