Crane oversail and what planning permission does not grant

Planning permission does not give you the right to swing a crane jib over your neighbour's land. Oversailing another party's airspace is trespass, it is a private law matter between two landowners, and no planning officer, condition or approval touches it. A tower crane on a constrained site therefore needs a separate oversailing licence negotiated with every affected owner, and the negotiation has to happen before the construction programme assumes the crane is there.

The courts settled the principle decades ago. In the late 1980s the High Court held in Anchor Brewhouse Developments v Berkley House that jibs passing over neighbouring land were trespass and granted injunctions, departing from an earlier decision that had suspended relief. The practical effect is that an adjoining owner can stop your crane.

Why oversail is a private matter and not a planning one

Planning permission authorises development. It does not confer any right over land you do not own, and it does not override anybody else's property rights. That is the same principle that leaves a permitted scheme blocked by a restrictive covenant or by the absence of a right of access.

Crane oversail is the clearest example because it is so visible. A jib that weathervanes freely out of hours, which is exactly what a tower crane must be left to do in high wind, will cross a boundary on any tight urban site. Slew limiters can restrict powered movement within defined arcs. They cannot stop the jib turning into the wind when the crane is out of service.

That means the honest question at tender stage is not whether the crane will oversail. It is which owners it will oversail and what they will want.

Licences and what they normally contain

An oversailing licence is a commercial agreement. There is no standard form and no statutory tariff, and the price is whatever the two parties agree, which is why an owner who understands their position can ask for a great deal.

Terms that appear in most licences:

• the precise extent of the airspace granted, by drawing, with a height above which oversail is permitted
• a fee, often structured as a lump sum plus a weekly or monthly payment for the duration
• a prohibition on carrying loads over the neighbouring land at any time, which is the clause that most affects lifting plans
• insurance requirements, with the neighbour named, and an indemnity
• a schedule of condition of the neighbour's property, agreed before works start
• working hours, notification arrangements and a named contact
• an end date with consequences for overrunning

Get the schedule of condition done properly. It is the document that decides who pays for a crack that appears during the works, and an incomplete one costs far more than the survey.

Planning conditions that touch cranes without granting anything

Conditions do appear that relate to cranes, and they are easy to misread as authorising the crane position. They do not.

A condition requiring a Construction Management Plan to be approved before work starts will usually cover crane location, the extent of slew, out of hours parking of the jib, lighting and hours of lifting operations. A Construction Traffic Management Plan will cover the delivery and erection of the crane itself, which on a narrow street can involve a road closure and a mobile crane larger than anything else on the job.

Approving those plans means the council is content with the environmental effects. It says nothing about whether you have the private rights you need, and councils are careful to say so.

Aviation safeguarding and lighting

Height brings a different set of consents. Cranes near an aerodrome, and tall cranes generally, fall within aerodrome safeguarding arrangements, and the Civil Aviation Authority publishes guidance for crane operators on notification and on aviation warning lighting. Ministry of Defence safeguarding applies around defence aerodromes and other assets.

Practically, that means notifying the relevant aerodrome and, where required, fitting and maintaining obstacle lighting on the jib and providing details for promulgation to pilots. Where the site is near a hospital with a helipad, the helicopter approach path is a separate and frequently overlooked constraint.

None of this is triggered by the planning permission. It is triggered by the crane's height and position, and it is discovered late on more sites than it should be.

Highway licences for crane positions and lifts

A mobile crane standing on the public highway needs the highway authority's permission, usually through a licence or permit with conditions on outriggers, ground bearing pressure and protection of the carriageway. A lift over the highway will generally need a temporary road closure under the Road Traffic Regulation Act 1984, and closures require notice periods that vary by authority and by the scale of the closure.

Where the site abuts a railway, a canal or a river, the infrastructure owner's consent is needed for any lift over their land, and those organisations run their own approval processes with their own lead times. Oversailing a railway is treated very seriously and is not negotiated in a fortnight.

Negotiating before the programme depends on it

The moment your programme depends on the crane, your negotiating position is gone. That is the whole of the practical advice here.

Identify every affected owner at feasibility stage from title plans rather than from a drawing of the site. On a block with flats above shops there may be a freeholder, a management company and several long leaseholders, and a licence from the freeholder alone may not be enough. Where the neighbour is a commercial tenant with a business that lifting operations would disrupt, expect the disruption to be priced.

Then approach them early, with a plan, a schedule of condition offer and a proposed licence, while the crane position is still movable. An owner asked in February for a licence starting in September behaves very differently from one asked in August.

If agreement cannot be reached, the alternatives are a crane position that avoids the airspace, a smaller crane with a shorter jib, mobile cranes for individual lifts, or a construction method that avoids a tower crane. Each of those has a cost, and each is better than a site shut down by an injunction. The same logic applies to other neighbour-facing risks in construction, such as the settlement predictions that drive ground movement from piling next to existing buildings.

What to record in the construction plan

The construction management plan submitted to the council should show the crane position, the jib radius, the areas over which powered slew is restricted, the out of service weathervaning arc, the lighting proposed, and the hours of lifting. Say in the document that oversailing agreements are being obtained separately, because an officer who sees a jib radius crossing a boundary will otherwise ask.

Keep the licences, the schedules of condition, the insurance certificates and the aviation notifications in the same file as the approved plan. Where a scheme involves retaining part of an existing structure, the same file discipline applies to the temporary works, as it does in facade retention.

This is general guidance, not legal advice. Oversailing is a property law question and specialist legal advice should be taken before relying on any of it.

Browse the PlanScope report types to see which construction documents your application will need. Reports should be reviewed before submission, and we do not guarantee planning approval.