Most projects don’t fail because they’re impossible. They fail because something was misunderstood early. A policy overlooked. A constraint underestimated. A design pushed just a little too far. Planning isn’t only about what works.
It’s about what doesn’t—and why. understanding common pitfalls isn’t about caution. It’s about clarity.
Why Applications Get Refused
Not always for the reasons you expect
Refusals are rarely about a single issue. More often, they’re the result of misalignment.
The proposal doesn’t sit comfortably within its context
The scale feels excessive
The impact on neighbours is too great
Policy hasn’t been properly addressed
Sometimes the design is close. But “almost acceptable” isn’t enough in planning. Clarity and justification matter as much as the idea itself.
Common Design Errors
Design isn’t just about space. It’s about relationships. The most frequent issues are often subtle:
Extensions that dominate rather than complement
Poorly considered roof forms
Window placements that create overlooking
Internal layouts that drive external problems
Two schemes can be the same size – but one feels resolved, and the other doesn’t. Planning tends to favour the one that feels intentional.
Misinterpreting Permitted Development
Where small mistakes have big consequences. Permitted Development (PD) appears straightforward. But it’s precise.
Common issues include:
Measuring from the wrong ground level
Exceeding height limits by small margins
Misunderstanding boundary conditions
Assuming rights apply when they don’t
A few centimetres can change everything. From permitted – to requiring full planning.
Ignoring Local Policy
National rules set direction. Local policy makes the decision. It’s easy to focus on what feels reasonable – and overlook what is actually required.
Local plans often define:
Acceptable extension depths
Design expectations
Garden space standards
Character considerations
Ignoring these doesn’t make them disappear. It simply increases the likelihood of refusal.
Overdevelopment
The most common pressure point. It’s natural to want more space. But planning consistently asks a different question:
Is this too much for the site?
Overdevelopment can take many forms:
Extensions that reduce garden space too far
Excessive bulk relative to the original house
Loss of light to neighbouring properties
Schemes that feel cramped or overbearing
The limit isn’t just physical. It’s perceptual. When a proposal feels too heavy, too tight, or too dominant – it rarely succeeds.
A More Informed Starting Point...
Mistakes in planning are rarely dramatic. They’re incremental. A small misjudgement. An assumption left untested. A detail pushed just beyond what works.
But together, they shape the outcome. Understanding these pitfalls doesn’t limit design. It strengthens it. Because good projects don’t just aim for approval. They’re designed to achieve it – quietly, confidently, and from the very beginning.
Common Pitfalls & Mistakes
Common Pitfalls & Mistakes
Most projects don’t fail because they’re impossible. They fail because something was misunderstood early. A policy overlooked. A constraint underestimated. A design pushed just a little too far. Planning isn’t only about what works.
It’s about what doesn’t—and why. understanding common pitfalls isn’t about caution. It’s about clarity.
Why Applications Get Refused
Not always for the reasons you expect
Refusals are rarely about a single issue. More often, they’re the result of misalignment.
Sometimes the design is close. But “almost acceptable” isn’t enough in planning. Clarity and justification matter as much as the idea itself.
Common Design Errors
Design isn’t just about space. It’s about relationships. The most frequent issues are often subtle:
Two schemes can be the same size – but one feels resolved, and the other doesn’t. Planning tends to favour the one that feels intentional.
Misinterpreting Permitted Development
Where small mistakes have big consequences. Permitted Development (PD) appears straightforward. But it’s precise.
Common issues include:
A few centimetres can change everything. From permitted – to requiring full planning.
Ignoring Local Policy
National rules set direction. Local policy makes the decision. It’s easy to focus on what feels reasonable –
and overlook what is actually required.
Local plans often define:
Ignoring these doesn’t make them disappear. It simply increases the likelihood of refusal.
Overdevelopment
The most common pressure point. It’s natural to want more space. But planning consistently asks a different question:
Is this too much for the site?
Overdevelopment can take many forms:
The limit isn’t just physical. It’s perceptual. When a proposal feels too heavy, too tight, or too dominant – it rarely succeeds.
A More Informed Starting Point...
Mistakes in planning are rarely dramatic. They’re incremental. A small misjudgement. An assumption left untested. A detail pushed just beyond what works.
But together, they shape the outcome. Understanding these pitfalls doesn’t limit design. It strengthens it. Because good projects don’t just aim for approval. They’re designed to achieve it – quietly, confidently, and from the very beginning.