Domestic wind turbines and the permitted development limits

A domestic wind turbine permitted development right exists, and it is tighter than almost anyone expects. Part 14 of Schedule 2 to the General Permitted Development Order 2015 contains a class for a standalone wind turbine within the curtilage of a dwellinghouse, and it caps the overall height at 11.1 metres, the swept area of any blade at 3.8 square metres, and the separation from the curtilage boundary at the turbine's overall height plus ten per cent. One turbine only. On most rural plots the separation rule is what rules it out.

Part 14 has been amended and relettered more than once, so read the current consolidated text for the class letters before you quote them to a council.

What the standalone turbine class permits

The right covers the installation, alteration or replacement of a standalone wind turbine, meaning one on a mast rather than fixed to a building. A separate class deals with building-mounted turbines, with its own limits.

The headline limits for the standalone class are these.

The 11.1 metre figure is measured to the highest point the blade reaches, not to the hub. A mast height of 9 metres with a 2.2 metre blade radius puts you at the limit, which is why most machines marketed for domestic use come in at a hub height well under 10 metres.

The separation rule, and why it defeats most gardens

Take a turbine at the full 11.1 metres. Add ten per cent and you need 12.21 metres of clear distance, measured from the ground level at the base of the turbine to every boundary of the curtilage. A circle of radius 12.21 metres needs a plot with roughly 25 metres of clear width around the mast position.

That is not a garden. It is a paddock, and a paddock is frequently outside the residential curtilage even where it is within the title, in which case the right does not reach it at all. The curtilage question is the same one that governs garden buildings, and the reasoning in our note on the 50 per cent curtilage rule for garden outbuildings applies here too.

Measure before you specify. Get the title plan, pace the distances, and remember that a boundary with a highway sits where the title says rather than where the hedge is.

One turbine, and the heat pump problem

The class permits one standalone turbine, and it also interacts with the other microgeneration classes in a way that catches people.

A standalone turbine is not permitted where a building-mounted turbine is already present in the curtilage. More awkwardly, the turbine classes and the air source heat pump class in Part 14 exclude each other, so a property with an air source heat pump installed under permitted development cannot then add a turbine under permitted development, and the reverse applies as well.

For a rural owner trying to decarbonise a house, that is a genuine planning decision rather than a technical one. Pick the technology that matters most, install it under the class, and apply for permission for the second if you want both. Many councils treat a well-sited domestic turbine on a working holding sympathetically, so the application is not a formality but it is not hopeless either.

Designated land and listed buildings

The standalone turbine class is cut back or excluded on designated land, and it is excluded in the curtilage of a listed building and on land designated as a scheduled monument. Read the class conditions directly rather than relying on a summary, because the designations named differ between the classes in Part 14.

In practice, if your house is listed or you are in a conservation area, a National Park or a National Landscape, assume you need planning permission and plan the case accordingly. The arguments that work are about siting and backdrop: a turbine seen against a rising wooded slope reads very differently from one on a skyline, and the landscape assessment should say which you have.

Article 4 directions can remove Part 14 rights in a defined area. Check the council's Article 4 information, because a direction will not show on your deeds. The same caution applies to the other householder classes, as our piece on front garden paving, permeable surfaces and Class F explains.

The sound limit at the neighbouring window

Part 14 attaches a condition requiring the installation to comply with the microgeneration planning standard, or an equivalent standard. That standard sets out how to assess sound at an assessment position, which is the nearest neighbouring habitable room window, and the level that must not be exceeded.

Read the current version of the standard for the figure, because it has been revised. What matters practically is the method. The assessment uses the manufacturer's declared sound power data, the distance to the assessment position, the terrain and the wind speed distribution for the site, and it produces a predicted level that is compared against the limit.

Three things make a domestic turbine fail that test. A short distance to a neighbouring house, which is common on a plot that only just satisfies the separation rule. A machine with high declared sound power, often an older three-blade design. And a mast position that puts the turbine upwind of the neighbour in the prevailing direction.

Get the assessment done before you buy the machine. A supplier's statement that a model is suitable for permitted development is not the same as a site-specific assessment, and the council can ask for one. Where the margin is tight, a Noise Impact Assessment from an acoustician is the document that settles it, and councils expect a suitably qualified author for that work.

Removal when it is no longer needed

The class carries a condition requiring the turbine and its mast to be removed as soon as reasonably practicable once it is no longer needed for microgeneration, and requiring the site to be restored.

That condition is enforceable and it travels with the installation. A disused mast left standing for years is a breach, and it is exactly the kind of visible, easily evidenced breach an enforcement officer will act on. Decommissioning also tends to be more expensive than owners expect, because the foundation is substantial and the crane access has to be arranged again.

Factor the removal cost into the appraisal, and if the holding is to be sold, deal with the mast explicitly in the sale rather than leaving a buyer to discover an obligation.

Where permission is needed instead

Apply for planning permission if any of the following is true. The machine exceeds 11.1 metres overall or 3.8 square metres of swept area. The separation distance cannot be achieved. There is already a turbine or an air source heat pump in the curtilage. The property is listed or on designated land. The proposed position is outside the residential curtilage, on a field or paddock. Or an Article 4 direction has removed the right.

A full application for a single domestic turbine is a minor application, and the case turns on landscape and visual effect, sound at neighbouring dwellings, and in some locations on aviation safeguarding and shadow flicker. The supporting documents are usually a planning statement with the policy case, a landscape and visual appraisal proportionate to the scale, and the sound assessment. Where the holding is near a safeguarded aerodrome, expect a consultation and allow time for it.

A planning statement that sets out the limits you cannot meet, the reason the position was chosen and the sound result is a far stronger submission than a form with a brochure attached. You can draft one on PlanScope from the Planning Statement page, then have it reviewed before submission. PlanScope provides AI-assisted draft reports for planning applications. Reports should be reviewed before submission. We do not guarantee planning approval.

This is general guidance, not legal advice. A lawful development certificate is the only formal way to confirm that works are lawful, so check your own position with your local planning authority or a qualified professional before relying on permitted development rights.