What Size Extension Can I Build Without Planning Permission?

What Are Permitted Development Rights?

Permitted development rights allow homeowners to carry out specific building works without needing to apply for planning permission from their local planning authority. These rights include house extensions, loft conversions, and conservatories. However, these rights are subject to limits to ensure that any development remains in line with local community interests.

Do You Always Need Planning Permission?

Not all extensions require formal planning approval. Many minor developments, especially those within certain size limits, are covered under permitted development rules. However, you must always check with your local authority as restrictions may apply to specific areas or property types.

Single Storey Extensions Without Planning Permission

Rear Extensions

For a single-storey rear extension, you can extend up to six metres for terraced or semi-detached houses and up to eight metres for detached houses under the larger home extension scheme. This is subject to prior approval, where your neighbours are consulted.

Side Extensions

For side extensions, the width of the existing house must not exceed half. This rule prevents developments that might unbalance the appearance of properties in the area.

Rules for Detached Houses

If you own a detached house, you can extend the rear of your home by up to eight metres without requiring planning permission. However, this must remain within the permitted development guidelines regarding height, width, and the impact on your neighbours.

Development Limits for Terraced and Semi-Detached Houses

The rules are more restrictive for semi-detached or terraced houses. Under permitted development, you can extend up to six metres, but as with detached houses, the height must not exceed the existing eaves of the home, and the roof pitch must match that of the existing roof.

Larger Home Extension Scheme

The larger home extension scheme allows homeowners to extend beyond permitted development limits for a rear extension. Under this scheme, with prior approval, you can apply for an extension of up to eight metres for a detached house or six metres for semi-detached and terraced houses.

Local Planning Authority and Their Role

While permitted development offers some flexibility, your local planning authority has the final say. They will check whether your extension falls under permitted development or if you need full planning permission. They also handle any neighbour consultation schemes that may arise when you extend your home.

Height and Distance Restrictions

The height of your extension is another important factor. Generally, a single-storey extension must be at most four metres in height. Additionally, any extension must be at least seven metres away from the rear boundary of your property to avoid affecting neighbouring homes.

Impact of Conservation Areas and Listed Buildings

The rules are stricter if you live in a conservation area or own a listed building. Permitted development may not apply, and you’ll likely need to seek listed building consent or full planning permission. Properties in outstanding natural beauty or national parks are also subject to stricter controls, and development rights may be more limited.

When You Need Prior Approval

Prior approval is required under certain circumstances, such as when applying for a larger home extension scheme. This involves notifying your local council, who will then inform your neighbours. If there are objections, the council will decide if the extension can proceed.

How Extensions Impact Neighbouring Properties

When planning an extension, it’s essential to consider its impact on neighbouring properties. If your extension is close to a neighbour’s boundary or significantly alters the light or privacy of their home, they may have grounds to object. Neighbour consultation schemes help ensure these concerns are addressed before construction begins.

House Extensions in National Parks and Protected Areas

Stricter rules apply if your property is within a national park or other protected land. You may find that your permitted development rights are reduced or removed entirely, and you’ll need to apply for planning permission for even minor extensions.

Building Regulations: Don’t Forget Them

Even if your extension falls within permitted development, you must still comply with building regulations. These ensure that your extension is safe, energy-efficient, and structurally sound. Building regulations are just as crucial as planning permission, from ensuring proper insulation to checking that the new roof pitch matches the existing one.

Conclusion

Extending your home without planning permission is possible, but you must stay within the permitted development rights. Always check with your local authority to ensure you follow the rules, especially if you live in a protected area or own a listed building. Understanding the size limits and other restrictions allows you to confidently extend your home without going through the formal planning application process. For professional assistance, consider reaching out to Builders London to ensure your project meets all requirements.