Planning Permission Requirements for Patios and Decking in London (2026)

Planning & Legislation | The Tree Amigos

Understanding the legal requirements for garden modifications is essential to ensure compliance with local authority regulations. In London's high-density residential areas, planning rules regarding privacy, drainage, and structural height are strictly enforced.

At The Tree Amigos, we provide professional guidance on navigating these statutory requirements. While many landscaping projects qualify as "Permitted Development," specific criteria must be met to avoid formal planning applications. This guide details the 2026 regulations for patios, decking, and retaining structures.

1. Permitted Development: The Baseline

In England, "Permitted Development" (PD) rights allow you to make certain improvements to your home without needing a formal planning application. For most rear-garden patios and decks, PD applies. However, your project must meet these specific criteria:

• The 300mm Rule: Any raised platform (decking or patio) must not be more than 30cm (1 foot) above the original ground level.
• The 50% Rule: The total area of outbuildings, extensions, and decking must not cover more than 50% of your total garden area.
• The Privacy Rule: If your deck is raised and overlooks a neighbor's window or garden, the council may require screening - even if it's under 300mm.

2. The Big Drainage Debate: SUDS Legislation

In London, the biggest cause of flash flooding is "urban squeeze" - the paving over of gardens. To combat this, the government introduced SUDS (Sustainable Urban Drainage Systems) legislation.

Front Gardens vs. Rear Gardens

If you are paving over your front garden (over 5 square metres), you MUST use a permeable surface (like porous resin or gravel) OR ensure the water drains into a garden border. If you use a non-permeable material like porcelain or concrete and let the water run onto the sidewalk or into the public drain, you legally require planning permission.

For rear gardens, while SUDS is technically less restrictive, The Tree Amigos always recommends installing a "soakaway" or ACO drains. London clay soil is notorious for poor drainage, and a massive new patio without proper drainage is just a swimming pool waiting to happen.

3. Conservation Areas & Article 4 Directions

London's beauty comes from its history, which is protected by Conservation Areas. In areas like Dulwich Village, Greenwich, or parts of Kensington, your Permitted Development rights may be restricted or removed entirely via an "Article 4 Direction."

In these zones, even a "minor" change like a high fence or a specific type of paving stone might require approval. It's always worth spending 10 minutes on your local council's planning portal to see if your street is under an Article 4 Direction.

4. Patios for Flats & Maisonettes

CRITICAL NOTE: If you live in a flat, maisonette, or a converted house, you generally DO NOT have Permitted Development rights. Almost any structural change to the external space of a flat requires a full planning application. We've seen many ground-floor flat owners forced to pull up new patios because they assumed the house-owner rules applied to them.

5. Retaining Walls & Garden Buildings

If your landscaping project involves building walls to level out a slope, pay attention to the height. Walls over 1 metre high next to a highway, or over 2 metres elsewhere, will likely need permission. Additionally, any "bespoke garden building" or pergola must not have an eave height over 2.5 metres if it's within 2 metres of your boundary.