Planning permission confuses a lot of homeowners — and understandably so. The rules are detailed, there are exceptions to the exceptions, and getting it wrong can be costly. Here's a plain-English overview to help you understand where you stand.

Permitted development rights

Many common home improvements fall under 'permitted development' — meaning they're automatically allowed without needing a planning application. These rights exist to reduce bureaucracy for routine work. However, they come with conditions, and they can be removed or restricted in certain areas.

Extensions

Single-storey rear extensions are often permitted development, subject to size limits. In most cases, you can extend up to 4 metres from the rear wall of a detached house (3 metres for semi-detached or terraced) without planning permission, provided the extension doesn't exceed 4 metres in height and covers less than half the garden area. Larger extensions may be possible under the Neighbour Consultation Scheme.

Side extensions, two-storey extensions, and anything that changes the roofline significantly are more likely to require permission.

Loft conversions

Most loft conversions are permitted development, provided the additional roof space doesn't exceed 40 cubic metres (50 for detached houses), the roof isn't raised above the existing ridge line, and no dormer faces the highway. Mansard conversions and hip-to-gable extensions are more likely to need permission.

Outbuildings and garden rooms

Outbuildings within the curtilage of a house are generally permitted development if they're single-storey, under 4 metres in height (2.5 metres if within 2 metres of a boundary), and don't cover more than 50% of the garden. They must not be used as a separate dwelling.

Driveways

Replacing a front garden with a driveway requires planning permission if the surface is impermeable (such as tarmac or concrete) and the driveway is over 5 square metres. Permeable surfaces — gravel, permeable block paving, or grass — don't require permission regardless of size.

When permitted development doesn't apply

• Listed buildings — almost all external changes require listed building consent
• Conservation areas — restrictions on extensions, cladding, windows and outbuildings
• Areas of Outstanding Natural Beauty (AONB)
• Properties where permitted development rights have been removed by a planning condition
• Flats and maisonettes — different rules apply

Always check before you build

The safest approach is to check with Hart District Council's planning department before starting any significant work. A Lawful Development Certificate — a formal confirmation that your project is permitted development — costs money but provides legal certainty and is useful when you come to sell.

This advice is provided for general guidance only and does not constitute legal or professional advice. Always consult a qualified professional for your specific situation.