The height rule is not the whole test
The Planning Portal describes the permitted development height limit for decking and raised platforms as no more than 30cm above ground. A design above that allowance should not be assumed to be permitted just because its footprint is small or a similar deck exists next door. Planning is about your property and proposal.
On sloping ground, the deck can appear low beside the house and much higher at its outer edge. Do not choose a convenient reference point to make a raised design fit the rule. Provide the local planning authority with the existing ground and proposed levels and ask how the test applies to your site.
Understand the combined coverage allowance
The 50% test concerns the combined garden coverage of decking, other extensions and outbuildings, not a separate half-garden allowance for each new project. Existing development therefore matters when considering a further deck. A large open lawn does not settle the calculation if other structures already occupy the surrounding land.
Prepare a plan showing the house, garden boundaries and relevant development. If you are unsure what must be counted, check the official guidance or ask the council. This site does not build sheds or summerhouses, but existing garden buildings can still matter to the planning assessment of proposed decking.
Location and protected properties
Decking must not be forward of a wall forming the principal elevation under the ordinary householder permitted development guidance. The street-facing position therefore needs considering as well as height. A front platform is not automatically treated like a small rear garden deck.
On designated land, including conservation areas, the Planning Portal says decking is not permitted to either side of the house under these rights. Decking within the curtilage of a listed building is not permitted development. Further limits apply in certain protected landscapes. Check the full official conditions rather than assuming every rear location is unrestricted.
Decking
- Timber and composite choices
- Strong subframe construction
- Steps and edges finished neatly
Flats and locally restricted rights
The householder permitted development allowances do not apply to flats or maisonettes. Ownership or access to a private garden does not change that distinction. A lease may also impose separate consent requirements, so planning permission is not the only approval to investigate.
For houses, conditions on a previous permission or an Article 4 direction can remove rights that would otherwise apply. Ask the council about restrictions affecting the actual address. The local authority is the appropriate source for a site-specific answer, particularly where the property has been converted, extended or is in a protected area.
Planning permission and safe construction differ
A deck within permitted development still needs suitable structural support, fixings and access arrangements. Permission status does not establish that a frame is safe, or that every railing and step detail is appropriate. Consider the intended use and any relevant building requirements separately from the planning question.
Views towards neighbours, changes in privacy and water movement are also worth discussing when choosing the layout. Moving a deck or reducing its level may be a more practical response than designing first and checking permission afterwards. The material comparison guide covers timber and composite once the basic shape and position are understood.
Get the answer before ordering materials
Start with the intended footprint, height and position on a measured sketch. Record existing outbuildings and explain any slope. Use the Planning Portal decking guidance and the government householder technical guidance, then seek confirmation from the local planning authority where anything is unclear. A lawful development certificate may be useful where you need formal confirmation.
Ashley can discuss the proposed decking work and quotation, but the council determines planning requirements. Read the decking cost guide for the existing published guidance, keeping any permission or design tasks distinct from the construction allowance. Do not treat a free site quotation as planning approval, and resolve the applicable checks before work begins.
Planning a deck? Book decking
Send Ashley a description of the proposed work, your location and any photographs that help explain the condition or layout. The service page explains the relevant work; the existing enquiry form is the place to request a site quotation. Agree the actual scope before committing to materials.