Do You Need Planning Permission for Decking?

In most cases, you don’t need planning permission to build decking in your garden — but that depends on how big it is, how high it’s raised, and where it’s positioned. The key factor in planning law is whether the decking counts as a minor garden improvement or a more permanent structure that could affect neighbours, drainage, or the character of the area.

Decking is generally treated as an external platform under UK planning law. If it’s low to the ground and takes up a modest part of your garden, it’s usually fine. However, if the decking is raised significantly or covers a large area, you may need formal approval. The moment your decking starts to impact privacy, block light, or overlook neighbouring properties, it comes under planning control.

Are Most New Deck Builds Classed as Permitted Developments?

Yes — most new decking projects are classed as permitted development, which means they don’t require planning permission. The government allows homeowners to make small-scale changes to their gardens and outdoor spaces without going through the planning process. As long as your decking meets the rules on height and area coverage, and isn’t located in a protected area or tied to a listed building, it likely falls within these rights.

This is one of the reasons why decking has become so popular — it’s a quick, low-hassle way to improve outdoor living space without red tape. But like all permitted development rights, there are limits. If your decking goes over them, permission will be needed.

What Does This Mean?

When a deck is considered permitted development, it means you’re legally allowed to build it without applying for planning permission — but only if you stick to specific limits. This includes how high the decking is above ground level, how much of your garden it covers, and whether it causes any disruption to your neighbours or changes the appearance of the property in a sensitive location.

Permitted development rights can also vary based on where you live. Just because decking is allowed in one area doesn’t mean it’s automatically allowed in another. In conservation areas, National Parks, or for listed buildings, these rights are often restricted or removed altogether.

Should You Consider Planning Permission When Building Raised and Large Decks?

Yes — the higher or larger your deck, the more likely you’ll need planning permission. Under current UK rules, if your decking is raised more than 30 centimetres (about one foot) above the natural ground level, it is no longer classed as permitted development and you will need planning permission. That includes raised platforms, steps, and multi-level decks.

Large decked areas can also trigger planning scrutiny — even if they are low to the ground. If your deck covers a significant portion of the garden or creates issues with drainage, privacy, or light, the local authority may consider it a material change that requires permission.

You should also think about the visual impact. A large deck in a small garden can be seen as overdevelopment, especially if it’s close to a boundary or affects your neighbours. Councils receive many complaints about high decks overlooking gardens or blocking sunlight — and they’re well within their rights to enforce changes or removal if planning rules are breached.

Do You Need Planning Permission if You Live in a Listed Building or in a Conservation Area?

If you live in a listed building, then yes — almost any alteration, including garden decking, will require listed building consent. This is a separate process from planning permission and is assessed based on how the proposed work affects the building’s character. Even decking that seems minor can be refused if it changes the setting or historical integrity of the site.

In a conservation area, things are more nuanced. Some decking may still fall under permitted development, but many councils apply stricter design controls in these zones. They may also remove permitted development rights altogether using an Article 4 Direction. That means any decking, no matter the size or height, could require a planning application.

In both scenarios, the safest option is to speak to your local planning authority before you start. They’ll be able to confirm what you can and can’t do and whether any special rules apply to your property.

When Do You Need Planning Permission for Decking?

You’ll need planning permission for decking if it meets any of the following conditions: it’s more than 30cm above ground level, it covers more than 50 percent of your garden (including any other buildings or structures), it’s located in front of the principal elevation of your house, or if your permitted development rights have been removed.

You’ll also need permission if your property is listed, in a protected area, or if the decking causes a planning issue like overlooking or loss of light for neighbouring homes. Just because a structure is in your garden doesn’t mean it’s exempt from planning rules.

How Big Can Decking Be Without Planning Permission?

The size limits are straightforward. As long as your decking is no higher than 30cm above the existing ground level and the total area of ground covered by the deck and other garden structures is less than 50 percent of your garden, you can build it without permission.

It also needs to be positioned behind the front wall of your house — decking at the front of a property is almost always classed as development and requires approval. Remember that these limits include not just the deck itself, but any raised steps, railings, or structures attached to it.

If your deck pushes past any of these thresholds, or if you live in an area with tighter controls, you’ll need to submit a planning application before building.

The 30cm Rule Is Strictly Enforced

Many people assume they can “fudge” the height a little — but councils take the 30cm (12 inch) rule very seriously. That’s the maximum height decking can be above natural ground level before it needs planning permission. If you build on a slope and use supports or levelling to keep the deck surface flat, it’s measured from the highest exposed point — not where it’s lowest or most convenient. Even adding steps, balustrades, or flower boxes can push you over the limit if they’re raised with the deck.

Cumulative Development Matters

Your decking isn’t judged in isolation. If you’ve already added things like a shed, pergola, summer house, or extension, all of these count toward the 50% garden coverage rule under permitted development. That rule applies to all outbuildings and structures combined. If your decking tips the total over the limit, you could be in breach, even if it’s a small area on its own.

Neighbours Can Trigger Enforcement

Planning departments don’t inspect every deck build — they mostly act when someone complains. And decking often causes disputes, especially if it's overlooking someone’s garden or blocking their light. If your neighbour reports it, the council will inspect, and if they find it too high or too large, you can be ordered to take it down, reduce it, or apply retrospectively — which can be refused.

Even if you’re confident you’re within your rights, it’s worth talking to neighbours first, especially if your garden is overlooked, or the deck is close to a boundary.

Drainage and Water Run-Off Can Be a Problem

Large decked areas can change how rainwater drains from your garden. If you’re in a flood-risk area, or your deck sits above a hard surface like concrete or clay, your local authority may raise concerns about water run-off. In some cases, you might need to include a drainage plan with your planning application, or show that your build won’t increase flood risk on neighbouring land.

Safety and Building Regs (Even If Planning Isn't Needed)

Planning permission is one thing — Building Regulations are another. While standard garden decking doesn’t usually require Building Regs approval, if you’re installing electrics, heating, or if the deck is part of a larger raised platform, balcony, or roof terrace, then the structure may need to comply. This includes things like:

• Structural support

• Fire safety (for attached decks near boundaries)

• Electrical installations (must be signed off under Part P)

If you’re connecting lighting, outdoor sockets, or installing permanent fixtures like hot tubs, it’s worth involving a qualified contractor to ensure the setup is safe and compliant.

Front Gardens Are a No-Go Without Permission

Even a small deck in the front garden almost always requires planning permission. The rules are stricter because of the visual impact on the street scene. If you build decking forward of the front wall of your house — especially facing a public road — you’ll need formal approval. This is where councils tend to be least flexible.

Don’t Assume You Can Build First and Ask Later

Some people go ahead without checking, assuming they can apply after if needed. But retrospective planning applications aren’t a sure thing. If you’ve already built something the council doesn’t like — especially if it affects neighbours or breaks size rules — they can refuse the application and issue an enforcement notice, which legally requires you to remove or change the decking. That’s time-consuming, stressful, and expensive — especially if it’s been integrated with lighting, seating, or landscaping.

Final Thought

The key point is this: decking can fall under permitted development, but only when done right. That means staying within the 30cm height limit, respecting the 50% garden rule, considering the visual and privacy impact, and checking for local restrictions like Article 4 Directions or conservation area rules. What feels like a simple DIY project can turn into a planning issue fast — so it’s always worth doing your checks before you build.

Decking can be a great way to add outdoor space and increase the value of your home — but it’s not a free-for-all. The planning rules are clear, and councils do take action against structures that go too far. Before you start digging or building, make sure you know your limits, speak to your local planning authority if unsure, and get confirmation in writing if needed.