Using aerial and street level imagery as planning evidence

Publicly available aerial and street level imagery is good evidence of what a site looked like on one particular day, and weak evidence of almost anything else. Used well it settles boundary lines, roof forms, parking layouts, tree canopy extent and the character of a street, all without leaving the office. Used carelessly it produces a planning application that asserts a building has stood for twelve years on the strength of a photograph nobody can date.

The whole discipline comes down to one habit: record the capture date and the source next to every image you use, and design your argument around what an image on that date can honestly prove.

What imagery can settle and what it cannot

Aerial imagery is reliable for two-dimensional facts. Built footprint, hardstanding extent, boundary treatment position, canopy spread, the presence or absence of a structure, the relationship between a site and its neighbours. At typical resolutions it will not tell you the height of anything, the condition of a roof, whether a wall is brick or render, or whether a window is obscure-glazed.

Street level imagery adds elevation, materials, the position of a dropped kerb, sight line obstructions, the number of storeys and the presence of a shopfront. It is captured from the highway, so it shows only what faces the highway. Rear elevations, garden depth and the relationship to neighbouring habitable windows are routinely invisible.

Two more limits catch people out. Oblique aerial views exaggerate height and hide ground levels, which matters when you are arguing about a ridge line. And both types of imagery are processed, so a stitched panorama can misplace a boundary by a metre or more. For anything you would defend at an inquiry, use imagery to orient yourself and a measured survey to make the claim.

Environment Agency LIDAR coverage is a useful complement, because it gives you terrain and surface models across most of England at a stated resolution and capture date. It helps when you are sanity-checking whether a site sits above or below a nearby watercourse before commissioning a Flood Risk Assessment. It is not a topographic survey and should never be presented as one.

Finding the capture date and why it decides the point

Commercial imagery layers usually carry a capture date in a corner caption or an attribution panel. Open datasets carry it in the metadata record. Historical aerial photography held by the Historic England Archive carries a sortie date. In every case, find the date before you plan the argument.

Three things follow from the date.

The first is relevance. Imagery captured after the application was validated says nothing about the baseline the authority is assessing. Imagery captured before a permitted development conversion says nothing about the current lawful position.

The second is gaps. Street level capture in rural areas can be five or more years apart, and a single capture in a dense urban area may be the only view of a building that has since been demolished. Where the gap straddles the event you care about, imagery narrows the window rather than proving the point.

The third is drift. Some platforms display an imagery date for a tile that was assembled from several sortie dates. If the argument turns on a month, get the underlying record rather than relying on a caption.

Imagery in a lawful development certificate

This is where imagery earns its keep and where it most often falls short. A certificate of lawfulness for an existing use or development under section 191 of the Town and Country Planning Act 1990 is decided on the balance of probabilities, and the burden sits with the applicant. Immunity periods changed in England, with the former four-year rules for building operations and change of use to a single dwellinghouse replaced by a single ten-year period for breaches occurring on or after 25 April 2024. Older breaches keep the previous position, so the date of the breach determines the test.

Imagery can establish that a structure existed on a given date. It cannot establish continuity, and continuity is what the test needs. A building visible in 2014 and 2025 imagery does not prove uninterrupted use in the years between, and an authority is entitled to say so.

Build the evidence in layers.

1. Dated imagery for the start point and the end point of the period.
2. Statutory declarations from people with direct knowledge, covering each year.
3. Documentary records that tie to dates: council tax bands, utility accounts, tenancy agreements, invoices for works, insurance schedules.
4. Any council record, such as a complaint file, an enforcement enquiry or a refuse collection change.

Present the imagery as an appendix with a table of dates and sources, and cross-refer each image from the statement of case. An officer who has to hunt for the date will discount the image.

Licensing, copyright and the public register

Imagery is licensed, and a planning application is a public document that the authority publishes online more or less permanently. Those two facts interact.

Check the terms of the service you are taking the image from before you paste it into a document that will be published. Some allow use in professional reports with attribution, some restrict redistribution, and some allow screenshots only within their own viewer. Open government data published under the Open Government Licence can be reproduced with attribution, which is one practical reason to favour it for anything that will be printed.

Location plans are a separate matter. Applications require an up-to-date base plan at an appropriate scale with the site outlined, and that plan needs to come from a properly licensed source rather than a screenshot of a mapping website. Authorities do reject applications on this point at validation.

Privacy deserves a sentence of thought rather than a policy. Street level imagery is published with faces and number plates blurred, and you should not defeat that by zooming and cropping. Avoid submitting images that show the inside of a neighbour's home, their garden in detail, or a vehicle registration. Where you need to show a neighbouring window for a daylight or overlooking argument, an annotated elevation drawing does the job with less exposure.

Annotating imagery so an officer can use it

An unlabelled image is decoration. A labelled one is evidence. Every image in a submission should carry the source, the capture date, a north arrow where it is a plan view, an approximate scale bar or a statement that it is not to scale, and a caption saying what it is being used to show.

For photographic evidence, add a viewpoint plan. Number each viewpoint, mark the position and direction on a site plan, and use the same numbers in the text. This is standard practice in landscape and townscape work and it takes ten minutes on a householder scheme.

Where the image supports a heritage argument, be explicit about what it demonstrates. A 1970s aerial photograph showing a rear wing that has since gone is a fact that belongs in the significance section of a Heritage Statement, with the archive reference and the sortie date. Without those, it is an unattributed picture.

Resist over-annotation. Three arrows and a short caption beat a dozen coloured overlays that the officer has to decode.

The site visit imagery cannot replace

Some things have to be seen. Ground levels across a sloping site. The condition and species of trees, which drives the BS 5837 survey and the constraints plan. Boundary ownership features such as which side the fence posts sit on. Drainage outfalls, manhole covers and evidence of standing water. Noise sources that only operate on weekday mornings. Internal room layouts and window positions, which no external image will give you.

Access work is the clearest example. A visibility splay depends on the actual position of hedges, signs, parked cars and the back of footway, measured on the ground. Checking whether a public right of way crosses the site needs the definitive map, then a walk. Habitat calls need the same treatment, as our note on reading habitat inventories sets out, because a mapped polygon is a starting hypothesis.

Use imagery to arrive at the site knowing what to look for. That is the honest role for it, and it saves a second visit.

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.

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