One of the first questions clients ask when considering a new home, extension, or redevelopment is simple: how long will planning permission take?
In practice, the answer is more nuanced. As our Project Director Katerina often highlights, planning permission in London depends heavily on the type of build, the scope of the project, and the borough you’re building in. While there are statutory timeframes, real-world planning rarely follows a single, predictable timeline.
This article breaks down what typically affects timescales for London planning, what you can realistically expect, and how to reduce delays.
One of the most common frustrations homeowners face is discovering that planning permission isn’t as clear-cut as they expected. Rules feel inconsistent, advice conflicts, and what worked for someone else doesn’t always apply to you.
The reason is simple: planning permission is shaped by context, and context is rarely identical from one property to another.
This article explains what “property context” actually means, how it affects planning outcomes, and why treating planning as a generic process often leads to delay, redesign, or disappointment.
Planning Permission Is Context-Driven, Not Rule-Based
Planning permission is assessed in relation to where a property sits, not just what is being proposed.
This means decisions are shaped by:
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Legal designations
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Local planning policies
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The character of the street and wider area
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How a proposal interacts with its surroundings
Two similar extensions can receive very different responses if the context around them differs, even subtly.
This is why online advice often feels contradictory: it’s usually missing the context that made it true in the first place.
Property Age vs Legal Status: A Common Source of Confusion
The age of a property does not determine what you can or can’t do — its legal status does.
Many homeowners assume that because a house is old, it must be restricted. In reality:
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A period property has no automatic planning constraints
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A listed building does
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A modern property can still face restrictions if it sits in a sensitive area
Age influences character, but designation influences permission.
Understanding this distinction early can prevent incorrect assumptions from shaping design decisions.
What typically causes delays?
Common reasons planning applications overrun include:
- Requests for design amendments
- Late consultee responses
- Neighbour objections requiring further assessment
- Incomplete or unclear submissions
A well-prepared application, supported by a clear planning statement and coherent design rationale, tends to move more smoothly through the system.
Conservation Areas: More Nuanced Than Most People Expect
Conservation areas are about protecting the character of an area, not freezing it in time.
Being in a conservation area:
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Does not automatically prevent extensions or alterations
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Does not remove all permitted development rights
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Does introduce greater scrutiny of visible changes
What matters most is whether a proposal is seen to preserve or enhance the area’s character.
This is why conservation-area projects often succeed when they are:
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Proportionate
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Well-considered
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Responsive to their surroundings
Article 4 Directions: Specific, Not Blanket
Article 4 Directions remove specific permitted development rights, not all of them.
They are often misunderstood because:
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They don’t apply to every conservation area
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They vary by borough, and sometimes by street
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They target particular elements (such as roofs, windows, or front elevations)
Article 4 does not mean “no development”.
It means development requires permission where it otherwise wouldn’t.
Failing to identify whether Article 4 applies, and what it applies to, is one of the most common early mistakes.
Why Your Neighbour’s Extension Doesn’t Set a Precedent
Planning decisions are contextual, not transferable.
Even on the same street, differences can arise due to:
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Changes in planning policy over time
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Variations in designation
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Differences in plot orientation or visibility
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Updated conservation appraisals
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Officer interpretation within policy
Neighbour approvals can provide insight, but they are not guarantees.
Relying on them without deeper context often leads to false confidence.
What People Usually Miss Until Planning Is Underway
The most common issues arise when:
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Design begins before context is fully understood
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Conservation status is assumed rather than checked
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Article 4 restrictions are discovered late
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Layout and usability are not considered alongside permission
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Planning approval is treated as the finish line
By the time these issues surface, momentum,and cost, have already gone.
Why “Straightforward” Projects Rarely Are
Even modest projects can become complicated when:
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Multiple policy layers overlap
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Rights differ between elevations
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Context-sensitive judgement is required
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Design quality influences acceptability
Planning becomes more predictable when context is understood early but it is rarely simple in absolute terms.
What This Means Before You Design Anything
Before committing to drawings, applications, or consultants, it’s worth clarifying:
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What legal designations apply to your property
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Which permitted development rights exist and which don’t
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How sensitive your setting actually is
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aWhether ambition and context are aligned
Understanding context doesn’t limit possibility.
It defines the route to a viable outcome.