State of Britain's SSSIs
A single site page can only tell you about that site. Aggregated across every SSSI with published condition-monitoring data, a bigger picture emerges — and it's not a comfortable one.
Covers England (Natural England) and Scotland (NatureScot) only — Wales and Northern Ireland's agencies don't yet publish this data in a form mappp.co.uk imports.
What do "Favourable", "Unfavourable" and "Declining" actually mean?- Favourable
- The feature is being adequately conserved — monitoring shows it meets all its site-specific targets.
- Unfavourable Recovering
- Not yet fully conserved, but the actions needed to fix it have been identified, at least one is underway, and none are behind schedule.
- Unfavourable No Change
- Not being conserved, and won't reach favourable condition unless management or external pressures change.
- Unfavourable Declining
- Not being conserved, won't recover without change — and is actively getting worse.
- Part Destroyed
- Part of the feature has suffered lasting damage and is irretrievably lost — it will never recover.
- Destroyed
- The entire feature has suffered lasting, irretrievable damage. No amount of management will bring it back.
Definitions per Natural England's Common Standards Monitoring framework, as published at gov.uk.
Red, amber and green straight off the data: green is Favourable, amber is Unfavourable Recovering (heading the right way, not there yet), red is everything with no positive trajectory — No Change, Declining, Part Destroyed or Destroyed. 13% of all units specifically are Declining — actively getting worse, the most urgent slice of that red.
Natural England's own official reporting — the England Biodiversity Indicator that feeds State of Nature — counts green and amber together as "on track", since recovery work is under way rather than the feature having failed. On that basis this data would read 76% on track. That won't match their published 62% exactly — our data is unit-scale rather than their current feature-scale assessment, spans assessment dates from 1998 to the present, and combines England with Scotland — but it's the same kind of data, already this bleak on the more generous framing.
By nation
| Agency | Units | 🟢 Favourable | 🟡 Recovering | 🔴 Red |
|---|---|---|---|---|
| Natural England | 26,683 | 43% | 33% | 23% |
| NatureScot | 3,679 | 66% | 6% | 29% |
By habitat type
Sorted worst (most red) first. A site is counted under every habitat it's tagged with, so rows aren't mutually exclusive. Habitats with very few units carry a much noisier percentage — the unit count is shown so you can judge that yourself.
By year assessed
This is not the same sites re-surveyed over time — checked directly, no monitoring unit in this data has ever been assessed more than once. It's every unit bucketed by the year it happened to be most recently assessed, showing the condition mix within each year's cohort. That's a real trend signal only if assessment scheduling is roughly cyclical rather than agencies deliberately prioritising sites already suspected of declining — we can't rule that out from this data alone. Years with too few assessments to be meaningful are omitted; the two most recent years are combined into one "2025–26" bucket, since the latest year is still a partial, in-progress sample.
Two things line up with documented history, which suggests this isn't just noise: the 2009–10 jump in amber matches the government's own target at the time (95% of SSSI land favourable-or-recovering by 2010), and the sustained rise in red from 2021 onward — roughly three times the pre-2018 rate — coincides with the period State of Nature 2023 itself describes as the worst on record.