How a town measures its open space
How a town measures its open space. How an open space assessment works: surveys and audits of local provision, PPG17 methods, and the mapping of sites and catchments that feeds planning decisions.
- Published: September 15, 2026
- 1209 words
- 7 min read
An open space assessment counts what exists, tests it against what policy expects, and maps where people can actually reach it. The method is a sequence: define the types of open space, survey each site on the ground, audit quality and value, compare provision with local standards, then map sites and catchments so the numbers can be read against real geography. The output is an evidence base a council can defend at examination, not a wish list.
How a PPG17 open space assessment worked
Planning Policy Guidance 17, published by the UK government in 2002 and replaced by the National Planning Policy Framework in 2012, set out a typology of open space and a method for assessing it. The typology separated parks and gardens, natural and semi-natural greenspace, amenity greenspace, provision for children and young people, allotments, cemeteries, and civic spaces. Each type was assessed on its own terms, because a hectare of playing field and a hectare of woodland do different work.
The assessment had two halves. The first was a quantitative audit: how much of each type exists, where, and who owns it. The second was qualitative: how good it is, and how much people value it. A site could be plentiful in hectares and still fail, if the surface is poor, access is blocked, or the catchment is empty of residents. Consultants who ran these studies for councils often described the method in service pages that are now archived; the practice behind a PPG17 open space assessment is documented in that historical record, including the audits, consultation and mapping that fed it.
The guidance also asked for local standards, expressed as quantity, quality and accessibility. Quantity is hectares per thousand population. Quality is a scored condition. Accessibility is a distance threshold, usually a walk of a set number of minutes, applied to each type of space. Setting those standards locally was part of the work, not a national figure handed down.
What do surveys and audits of local provision actually record?
A survey is a site visit with a form. The assessor records the site boundary, the type of open space, the ownership, the primary use, and the condition of the things that decide whether people stay: paths, drainage, seating, bins, planting, lighting, play equipment, sports markings, fences and gates. Photographs are taken from fixed points so a later survey can be compared with the first.
An audit is the desk exercise that sits around the survey. It checks the site against policy designations, ownership records, planning history and any known maintenance issues. It also tests whether the site is genuinely open to the public, or nominally public but locked, overgrown, or reachable only through a private road.
Quality and value are scored separately, and the distinction matters. Quality is what the assessor sees. Value is what the community says the site does for them: a small, worn kickabout area next to a dense estate can score low on quality and high on value. A large, well-kept lawn with no one on it can do the reverse. The scoring bands are usually defined before the fieldwork starts, so the results are not adjusted afterwards to fit a preferred conclusion.
Consultation runs alongside the audit. It can be a household survey, a stakeholder workshop, a drop-in session at a leisure centre, or interviews with friends groups and sports clubs. The point is to capture use that the site visit cannot see: evening football, school runs, dog-walking routes, the paths people take when a gate is broken.
How is open space and its catchments mapped?
Mapping turns the audit into geography. Every surveyed site is drawn as a polygon in a geographic information system, with its type, ownership, quality score and value score attached as attributes. Population data is added at a fine grain, usually output areas or lower-layer super output areas, so the number of residents within a given distance of each site can be counted.
Catchments are drawn as buffers around sites, using the accessibility standard for that type of space. A buffer is a circle in the simplest version, but a straight-line radius overstates access where a river, railway or motorway cuts the route. More careful studies use network distance along paths and streets, and may weight the result by barriers and crossings.
The useful output is a gap map. Areas inside a catchment are covered; areas outside every catchment of a given type are deficient for that type. Overlaying the gap map on the population map shows how many residents are affected and where new provision, or an improved route to existing provision, would close the gap. Overlaying it on deprivation data and on planned housing growth shows where the pressure will land next.
Mapping also exposes double counting. A school field that is only open outside term time, a private sports ground with no public right of access, and a green corridor that is too narrow to enter are all easy to count as provision on a spreadsheet and hard to justify on a map.
What does the evidence base decide?
An open space assessment is written to be used. It supports the open space policies in a local plan, the developer contributions that fund new provision, and the decisions about which sites to protect, improve or release. It also feeds playing pitch strategies, green infrastructure plans and neighbourhood plans.
The assessment usually ends with recommendations ranked by type and by area: improve quality here, add provision there, secure access to a site that already exists, or protect a site that is doing more work than its condition suggests. Each recommendation should trace back to a survey record, a consultation response or a mapped gap, so that the reasoning survives a challenge.
One practical caution belongs here. Numbers move. Population grows, a school closes, a pitch is resurfaced, a housing allocation is added. An assessment is a snapshot with a stated date, and its standards need revisiting when the assumptions behind them change. Councils that treat the document as a one-off report rather than a maintained dataset tend to repeat the fieldwork sooner than they expected.
Why the method matters more than the headline figure
A single figure, hectares per thousand people, is the part of an open space assessment most often quoted and least often useful on its own. It says nothing about whether the space is any good, whether anyone can walk to it, or whether it is the kind of space residents asked for. The method exists to keep those questions attached to the number.
That is why the sequence holds: typology first, then survey, then audit, then standards, then mapping, then recommendations. Skip the survey and the audit becomes an opinion. Skip the mapping and the standards become an average that hides the places where provision fails. Skip the consultation and value is guessed rather than recorded.
For anyone reading a local plan or a planning application, the assessment behind it is worth finding. It shows what the council counted, how it judged quality, what residents said, and which areas the map left outside the catchments. Those four things explain most of the open space decisions that follow.
Latest articles
By Il Campari editorial desk. Filed under Italian aperitivo.