How Big an Extension Can I Build Without Planning Permission?

Thinking about extending your Hull home but worried about the planning permission process? You're not alone. Many homeowners assume they'll need to go through the lengthy and expensive planning application route, but the truth is, you can often build much bigger extensions than you think without needing planning permission at all.

At DB Construction, we help Hull families navigate these rules every day. Let's break down what you need to know in simple terms, so you can understand your options and start planning your dream Hull extension.

The Good News: Most Extensions Don't Need Planning Permission

The government has made it much easier for homeowners to extend their properties through something called "Permitted Development Rights." Think of these as pre-approved permissions that let you build within certain limits without having to apply for planning permission.

This means you can often add a substantial kitchen extension, extra living space, or even additional bedrooms without the stress, cost, and uncertainty of a planning application.

Single-Storey Extensions: Your Best Bet

Single-storey rear extensions are by far the most popular choice, and for good reason - the rules are quite generous.

Here's what you can build:

Smaller extensions (no paperwork needed):

• Detached houses: 4 metres out from your back wall

• Semi-detached and terraced houses: 3 metres out from your back wall

Larger extensions (with neighbour consultation):

• Detached houses: Up to 8 metres out from your back wall

• Semi-detached and terraced houses: Up to 6 metres out from your back wall

For the larger extensions, your immediate neighbours get told about your plans and have 21 days to object. If they don't object (and most don't), you can go ahead. It's much simpler and cheaper than full planning permission.

Two-Storey Extensions: More Limited

If you want to go up as well as out, the rules are stricter:

• Maximum 3 metres out from your back wall (for any type of house)

• Can't be too close to your neighbours' boundaries

• Must match your existing roof style

Two-storey extensions are brilliant for adding bedrooms upstairs and living space downstairs, but you're more limited in size.

Side Extensions: Possible But Restricted

You can build a single-storey side extension, but it:

• Can only be 4 metres high

• Cannot be wider than half your house

• Must be single-storey only

The Important Rules Everyone Needs to Know

The Half-Garden Rule: Your extension (plus any other outbuildings) can't take up more than half of your original garden space. This stops people from completely covering their gardens.

Height Limits: Your extension can't be higher than your existing house roof.

Materials: You need to use materials that look similar to your existing house.

Position: You can't extend towards the front of your house or beyond the side if it faces a road.

When These Rules Don't Apply

Unfortunately, not everyone can use these generous allowances:

Conservation Areas: If you live in a conservation area in Hull, the rules are much stricter. You're limited to just 3 metres for single-storey extensions, and two-storey extensions aren't allowed at all.

Listed Buildings: If your house is listed, these rules don't apply, and you'll need special permissions.

Flats: These rules only apply to houses, not flats or maisonettes.

Previous Extensions: If someone has already extended your house since it was built (or since 1948), that counts towards your limit.

The Neighbour Consultation Process

For larger single-storey extensions (6-8 metres for detached houses, or 4-6 metres for others), there's a simple process:

1. You submit basic plans to the council

2. They tell your immediate neighbours

3. Neighbours have 21 days to comment

4. If there are no valid objections, you can proceed

This costs much less than planning permission and usually takes about 6 weeks.

Building Regulations: Still Required

Here's something important: even if you don't need planning permission, you'll always need Building Regulations approval. This is separate and ensures your extension is safe, well-insulated, and properly built.

Don't worry though - at DB Construction, we can let you know what you need to do, and help with making sure everything falls under the correct regulations.

Real Examples: What This Means for Your Hull Home

Terraced House Example: On a typical Hull terraced house, you could build a 6-metre single-storey rear extension (with neighbour consultation). That's enough space for a large kitchen-diner that opens onto your garden - perfect for modern family living.

Detached House Example: With a detached house, you could go out 8 metres, creating a spectacular open-plan kitchen, dining, and family area that completely transforms how you use your home.

Two-Storey Option: Even with the 3-metre limit, a two-storey extension can add a bedroom upstairs and extend your kitchen or add a utility room downstairs.

Why This Matters for Hull Homeowners

With house prices in Hull continuing to rise, extending rather than moving makes real financial sense. A well-designed extension can:

• Add significant value to your property

• Create the space your family needs

• Avoid the stress and cost of moving

• Be completed much faster than you might think

Getting Professional Help

While these rules might seem straightforward, every property is different. Things like:

• Exactly where your boundaries are

• Whether previous owners have already extended

• Local restrictions in your area

• How to design within the limits

All affect what you can actually build. That's where experienced local builders like DB Construction come in. We can quickly assess your property, explain exactly what's possible, and build an extension that makes the most of your allowances.

The Bottom Line

You can probably build a much bigger extension than you think without needing planning permission. Whether it's a 6-metre kitchen extension on your terraced house or an 8-metre family space on your detached property, the opportunities are often much greater than homeowners realise.

The key is understanding the rules and working with professionals who can help you navigate them. At DB Construction, we've helped hundreds of Hull families create beautiful extensions within these guidelines, and we'd love to help you explore what's possible for your home.

Ready to find out what size extension you can build? Give DB Construction a call for a free consultation. We'll assess your property and explain your options in plain English, with no obligation and no confusing jargon.