Updated April 2026Built from national planning rules and local authority contextUse formal checks if the proposal is close to a limit or affected by special controls
Planning tool

Site Constraint Checker

Use this when the project is not the real problem and you need to isolate the live planning constraint instead. It identifies the blocker, shows what usually tightens it, and points you to the next page worth opening.

Constraint-first toolFast rule isolationDesigned for follow-up clicks
Interactive check

Check The Live Constraint

Work through the prompts, then let the tool show which planning constraint is most active and where to go next.

How to use the result

What This Tool Is Good For

What it answers well

It helps when the project is already known but the real blocker is height, depth, boundary position, roof change, frontage sensitivity or local control.

What it improves

Instead of sending you into a generic guide, it narrows the rule family that deserves the next check.

Best next move

Use the result to open the first rule page that matches the blocker, then use the wider route tools if the answer is still mixed.

Good search matches

Questions This Tool Is Best At Narrowing

Context and caveats

How This Tool Fits Into The Wider Planning Process

Site Constraint Checker is intended as a fast planning triage step based on common UK planning considerations and permitted development limits.

Use it to narrow the question, then move into project guides, local authority pages or formal confirmation if the scheme is close to a limit. The tool should help you spend money in the right order, not tempt you to stop checking too early.

Personalised planning guidance

Need A More Tailored Steer Than The Tool Result?

If site constraint checker has narrowed the question but the answer still depends on your exact site, local authority area or project details, use the email guidance route instead of relying on another broad rule of thumb.

Email your project details See how it works

Best for

Borderline, location-sensitive or awkwardly specific cases where a broad page is useful, but not quite enough on its own.

What the reply aims to do

Best when a broad guide has narrowed the issue but the live answer still depends on the details of your site, design or local authority area.

What to include

Property type, council area, location, the change you want to make, approximate dimensions, relevant heritage or flat-related details, previous additions and the main concern.

Important: Replies are informational personalised guidance based on the details you provide and publicly available information. They are not formal legal, architectural, surveying or council advice. Site-specific or borderline cases may still need checking with the local authority or a qualified specialist before drawings, applications or contractor spend move ahead.

Your enquiry details are used to respond to your request. Anonymised themes may be used to improve guides, tools, FAQs and site content. Identifiable case details are not published without permission, and sending an enquiry does not sign you up to marketing emails. Privacy notice.

If you want, you can also say that anonymous themes from your enquiry may be used to improve future guides and FAQs. This is optional and does not affect whether you receive a reply.

Good follow-up reads

FAQ Pages Worth Opening After The Tool

FAQ follow-up

How To Measure Height For Planning Permission

Useful when the live blocker is vertical scale and the measurement method matters as much as the design.

Read answer
FAQ follow-up

How To Measure Distance From Boundary

Helpful when siting and neighbour relationship are the practical issues that keep changing the answer.

Read answer
Where to go after the tool

Detailed Guidance Worth Opening Next

Next page

Depth Limits

Useful when projection or site spread is the first blocker.

Open guide
Next page

Height Limits

Open this when vertical scale is the main constraint.

Open guide
Next page

Boundary Rules

Helpful when neighbour relationship or siting is the live issue.

Open guide
Next page

Roof Alterations

Use this when visible roof change is the blocker.

Open guide
Next page

Planning Decision Engine

Helpful when the overall route still feels unresolved.

Open guide
Next page

Planning Route Planner

Use this next when the blocker is known but the approval path is still fuzzy.

Open guide
Useful companion tools

Related Planning Tools

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Do I Need Planning Permission?

Work through a structured project check to see whether the scheme looks likely permitted development, may need planning permission, or depends on local constraints.

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What Can I Build? Explorer

Explore the home project types that are most likely to fit your property before you dive into detailed planning checks.

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Extension Value Estimator

Estimate likely property value uplift from extension-led projects using project type, size, finish level and planning confidence.

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Related tool

Permitted Development Calculator

Estimate whether a common home project may fit within permitted development rules.

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Trust and method

Use These Tools Properly

What they are for

  • Reducing uncertainty at the start of the process.
  • Helping you pick the right next page quickly.
  • Spotting when the answer probably needs escalation before money is committed.

What they do not replace

  • Formal confirmation for borderline schemes.
  • Local authority checks where special controls apply.
  • Country-specific checking where England, Wales or Scotland follow different planning routes.
  • Detailed specialist input for complex cases.

When to escalate

  • The route only works if the scheme stays inside a tight limit.
  • Local controls, listed status or Article 4 may be doing most of the work.
  • You need written certainty before drawings, applications or contractor spend.

Methodology

Planning FAQ

Updated April 2026