Permitted Development vs Planning for Telford Extensions

If you are planning a house extension in Telford, Shrewsbury, Wolverhampton or the surrounding areas, the first question you need to answer is whether your project falls under permitted development or requires a full planning application. Get that assessment wrong and you risk enforcement action, costly demolition, or complications when you come to sell. This guide sets out the current national rules in plain English, flags where local restrictions can override them, and explains when you should seek formal confirmation before you build.

Important: Planning rules and property rights vary by location, property type, and local authority policy. This article is a general overview only — it is not legal or structural advice. Always verify your position with Telford & Wrekin Council (or your relevant local planning authority) and consult a suitably qualified professional before proceeding.

What Is Permitted Development?

Permitted Development (PD) is a nationally set grant of planning permission that allows certain works to a dwelling house without the need for a full planning application. The rules are contained in the Town and Country Planning (General Permitted Development) (England) Order 2015 (as amended). For extensions, the relevant class is Class A of Schedule 2, Part 1.

PD rights apply to dwelling houses only. Flats, maisonettes, and properties that have already been converted do not benefit from the same rights, and any extension that changes the use of part of a building — for example, creating a self-contained annexe — may require full consent regardless of size.

Single-Storey Rear Extensions

Under standard PD, a single-storey rear extension may extend:

Up to 4 metres beyond the original rear wall of a detached house
Up to 3 metres beyond the original rear wall of a terraced or semi-detached house

The Larger Home Extension scheme (prior approval route) permits greater depths:

Up to 8 metres for detached houses
Up to 6 metres for all other houses

This prior approval route requires a formal notification to the local planning authority and a neighbour consultation period before work begins. It is not the same as a full planning application, but it is not silent either.

Height limits for single-storey rear extensions:

Maximum overall height: 4 metres
If the extension is within 2 metres of a boundary: maximum height drops to 3 metres
Eaves and ridge must not exceed those of the existing house

Side Extensions

Side extensions under PD must be:

Single-storey only, with a maximum height of 4 metres
No wider than half the width of the original house at its widest point
Set back from the principal elevation facing the highway
Eaves height must not exceed 3 metres if within 2 metres of a boundary

A two-storey side extension is not permitted under Class A PD and will require a full planning application.

Two-Storey Rear Extensions

Two-storey rear extensions can fall within PD provided they:

Do not extend beyond the rear wall by more than 3 metres
Do not exceed the existing eaves height or ridge height
Use a roof pitch that matches the existing house as far as practicable
Have any upper-floor side-facing windows that are obscure-glazed and non-opening (unless the openable section is more than 1.7 metres above floor level)
Include no balconies, verandas, or raised platforms
Use materials of similar appearance to the existing house

General PD Conditions That Apply to All Extensions

Regardless of extension type, the following overarching conditions apply:

The total footprint of the extension, combined with all previous additions since the original house was built, must not cover more than 50% of the land surrounding the original dwelling
Cladding, balconies, and verandas are excluded from PD rights
Listed buildings require separate Listed Building Consent; PD rights do not apply
Properties within Conservation Areas, Areas of Outstanding Natural Beauty, National Parks, or subject to an Article 4 Direction may have reduced or removed PD rights — this is common in parts of the Telford & Wrekin district and neighbouring authorities, so always check locally

When Full Planning Permission Is Required

A full planning application is necessary when a proposal exceeds PD limits or the property is in a restricted category. Common triggers include:

Extension dimensions exceed the Class A thresholds above
A side extension is positioned forward of the principal elevation facing the highway
The extension includes a balcony, veranda, or raised platform
Changes to the cladding or external finish of the principal elevation (render, stone, timber, tile)
The property is a listed building, flat, or maisonette
The property sits within a Conservation Area or is subject to an Article 4 Direction
The development changes the use of any part of the building

Full planning permission involves a formal application to the local planning authority, a statutory consultation period, and a decision based on local policy and design guidance. The outcome is discretionary and not guaranteed, which is why understanding PD limits precisely — and building within them — is often the more certain route for straightforward extensions.

PD vs Planning Permission: At a Glance

Factor	Permitted Development	Full Planning Permission
Application required	No (LDC optional but advisable)	Yes
Typical programme	6–8 weeks for LDC	8–10+ weeks for decision
Size limits	Fixed PD dimensions	Set by local policy
Neighbour input	Limited (prior approval for larger rears)	Formal consultation
Materials	Must match existing house	Design-led; contrast possible
Balconies / verandas	Not permitted	Can be considered
Certainty of outcome	High if rules are met	Decision-based

Programmes are indicative. Local authority workloads vary and timescales can change.

Lawful Development Certificates Explained

Even when a project clearly sits within PD limits, applying for a Lawful Development Certificate (LDC) is strongly advisable. An LDC is not mandatory, but it provides the local planning authority’s formal written confirmation that the works are lawful as described. This matters for three practical reasons:

Resale and conveyancing — solicitors and buyers routinely request evidence that extensions were built lawfully. An LDC is the clearest proof available.
Mortgage lenders — some lenders require an LDC before releasing funds against a property with an extension.
Future protection — if PD rules change or a dispute arises, an LDC issued at the time of the works provides a documented record of lawfulness.

The application fee for an LDC is lower than for a full planning application, and the process is generally less uncertain because the decision turns on whether the facts meet the rules, rather than on planning judgment.

How TPC Approaches Extension Projects in Telford and Surrounding Areas

TPC Limited works with homeowners across Telford, Shrewsbury, Wolverhampton and the wider West Midlands and Shropshire corridor. Before any design is finalised, the team works through the structural and drainage requirements of a project — identifying potential constraints early rather than discovering them once work is under way.

Quotations are itemised so you can see exactly what is included. A programme portal gives homeowners live visibility of schedules, daily progress, design approvals and budget tracking throughout the build. Site management is structured to keep disruption manageable and communication clear between client and contractor.

If you are at the early stage of planning an extension and want to understand what is achievable within PD or whether a planning application makes more sense for your ambitions, TPC’s home extension service is a practical starting point. For more complex or bespoke projects, the bespoke building service covers projects that go beyond a standard extension scope.

Next Steps

Before committing to any design or starting on site:

Confirm your property type and whether it benefits from standard PD rights
Check with Telford & Wrekin Council (or your relevant LPA) whether any Article 4 Directions, Conservation Area restrictions, or listing applies to your property
Consider applying for an LDC even if you are confident the works fall within PD
Establish the structural and drainage requirements of your proposed extension before finalising dimensions

This guide reflects national permitted development rules as they stand at the time of writing. Rules are subject to amendment; always verify the current position with your local planning authority and a suitably qualified adviser.