Permitted development on land near an aerodrome

Aerodrome safeguarding quietly rewrites permitted development rights for anyone farming or building within three kilometres of an airfield perimeter. The most important example sits in Part 6 of the General Permitted Development Order 2015: the height limit for an agricultural building drops from 12 metres to 3 metres inside that zone. A grain store that would be permitted development two fields away needs a full planning application here, and a farmer who discovers this after the steel is ordered has an expensive problem.

The zone is measured from the aerodrome perimeter, not from the runway, and it applies to licensed civil airfields and to military aerodromes alike.

Where the reduced limits bite

Part 6 Class A permits agricultural development on units of five hectares or more, subject to a list of exclusions. One of those exclusions is height: a building, structure or works within three kilometres of the perimeter of an aerodrome may not exceed three metres. Outside that distance the general 12 metre ceiling applies.

Three metres is lower than it sounds. A modest portal frame with a two metre eaves height and a shallow pitch will breach it at the ridge. Grain bins, silage clamp walls, slurry stores, feed hoppers, polytunnel hoops and the tops of stacked bales are all caught, because the restriction covers structures and works rather than buildings alone.

Part 6 Class B, covering units between 0.4 and five hectares, carries its own restrictions and is more limited to begin with. Forestry development under Part 6 Class E has a separate set of conditions. Read the class you are relying on rather than assuming the rules are the same across the Part.

Other Parts of Schedule 2 handle aerodromes by consultation instead of by height. Several classes in Part 14, covering renewable energy, and Part 16, covering electronic communications, require the developer to consult the aerodrome operator, the Civil Aviation Authority or the Ministry of Defence where the site falls within a safeguarded area, and to take account of the advice given before proceeding.

Establishing whether your site is in the zone

Do not guess from a map measurement. Officially safeguarded aerodromes have safeguarding maps deposited with the local planning authority, and those maps define the consultation zones precisely. The planning department holds them and will check a postcode against them on request.

Ask three questions when you ring:

1. Is the aerodrome officially safeguarded, and if so which zones cover the site?
2. What consultation criteria apply, by height, by location and by type of development?
3. Is there also a birdstrike safeguarding zone, which extends considerably further than the height zone?

Many smaller and privately operated airfields are not officially safeguarded and rely on voluntary arrangements instead. That does not mean the constraint disappears. A council will still consult the operator informally, and an objection about aircraft safety carries weight whether or not the statutory machinery is engaged.

Military sites add another layer. Defence safeguarding covers aerodromes, technical sites and explosives storage areas, and the Ministry of Defence is consulted on development that could affect radar, communications or approach paths.

Solar, reflectivity and glint and glare

Solar development near an airfield attracts more scrutiny than almost anything else, and the reason is optical rather than structural.

Modern photovoltaic modules are designed to absorb light, and their reflectivity is lower than glass or water. Even so, a large array can produce specular reflection at certain sun angles, and the concern is a beam reaching a pilot on final approach or an air traffic controller in the visual control room. The assessment models the sun path across the year, the panel orientation and tilt, and the geometry of the approach and the tower, then reports when and for how long reflection could reach each receptor.

Where a risk is identified, mitigation is usually straightforward: adjust the tilt or the row spacing, change the azimuth, add anti-reflective coating, or plant screening that intercepts the line of sight. A ground-mounted scheme also raises the structural question, since the frame height and any tracking system need to stay within safeguarding limits.

Two further points come up on farm arrays. Inverter cabins and substation buildings are structures too, so their height counts. And the fencing, CCTV poles and cable route all sit within the application even though they feel like details. The wider evidence base for a rural array is set out in the report pack for a solar farm on agricultural land, and the practical sequencing is shown in a walkthrough of a solar array on farmland. Canopy schemes raise their own version of the height question, covered in getting permission for a solar canopy over a car park.

Lighting and bird hazard

Two issues catch people out because neither is obviously a planning matter.

Lighting comes first. Upward light spill, unshielded floodlights and any array of lights that could be mistaken for approach lighting will draw an objection. Specify full cut-off luminaires, set mounting heights low, cap the upward light output ratio at zero where possible, and show the layout on a plan. Very tall structures carry aviation obstruction lighting duties, which bite at 150 metres or more, and those obligations sit outside the planning permission rather than inside it.

Bird hazard is the second, and its zone is much larger than three kilometres. Anything that attracts flocking birds near an airfield is a safeguarding concern: open water, wetland habitat, landfill and waste transfer, food waste composting, fish ponds, and reedbed or attenuation basin features in a drainage scheme.

That last one causes real friction, because the same officer who wants sustainable drainage ponds may be dealing with an operator who wants none. The resolution is usually a bird hazard management plan, plus design changes such as steep-sided basins, sub-surface storage, netting, or planting chosen to be unattractive to gulls and geese. Raise it early, because redesigning a drainage strategy late is painful.

Consulting the operator and what to submit

Contact the aerodrome before you submit anything. Operators generally prefer a conversation to a consultation response, and a scheme that arrives with the operator's comments already addressed moves far more quickly than one that arrives cold.

Send them a site plan with a grid reference, the maximum height of every element above ordnance datum as well as above ground level, a section, the proposed materials with their reflectivity where relevant, the external lighting layout, and the construction programme including crane heights and durations. Cranes matter: a temporary tower crane on a low building can breach an obstacle limitation surface even though the finished structure does not.

For a Part 6 prior notification, the submission needs the standard details plus proof that the height limit is respected. Set out the calculation rather than asserting compliance. Where the design cannot come in under three metres, apply for full planning permission and deal with the safeguarding question directly in a Planning Statement, supported by the operator's written comments.

Keep in mind that permitted development rights are established by the facts on the ground, and the only formal way to confirm that works are lawful is a lawful development certificate. Where a scheme sits close to the three metre line, a certificate of proposed lawful use or development is worth the fee.

PlanScope drafts Planning Statements and supporting documents from your answers, structured to UK planning policy and flagged where site facts such as ground levels or safeguarding advice still need to be supplied. Reports are AI-assisted drafts that should be reviewed before submission, and we do not guarantee planning approval. This article is general guidance, not legal advice: confirm the safeguarding position with your local planning authority and the aerodrome operator before relying on it.