How much does planning permission really cost in Cornwall?

Most homeowners in Cornwall start with one question: how much will this cost? The answer they're expecting is a single number. The reality is a lot more complicated — and most people don't realise that until they're already mid-process. Tools like WhatCanIBuild exist precisely because the full picture is almost impossible to piece together on your own.

The £548 fee is just the beginning

Yes, the householder application fee is £548. But that number tells you almost nothing about what your project will actually cost to get through the system. On top of the application fee, most homeowners also end up paying for:

• Architect or planning consultant fees to draw up compliant plans
• Pre-application advice from Cornwall Council (which can cost extra but may save time)
• Supporting documents — heritage statements, design and access statements, ecology surveys — that may be required depending on your property
• A Planning Portal service charge of £75.83 + VAT applies to online applications with fees over £100

The supporting documents are where costs quietly multiply. Whether you need them — and which ones — depends entirely on your specific property. And that's where Cornwall gets complicated.

Cornwall's constraints are everywhere — and they're not evenly distributed

Cornwall has 145 conservation areas. That's an enormous number, spread across market towns, fishing villages, coastal settlements and rural hamlets. It means a huge proportion of homeowners in Cornwall are on streets where external alterations face additional scrutiny — but most won't know which rules apply to their specific address without checking.

Then there's the listed buildings question. With over 5,000 listed buildings recorded across Cornwall, listed building consent adds a separate layer entirely — and crucially, carries no application fee. But the hidden costs of getting a listed building application right (specialist reports, heritage consultants) can dwarf the savings.

And that's before you factor in Cornwall's AONB boundaries. Properties near or within the Cornwall, North Devon and Tamar Valley AONBs, or close to the Cornwall and West Devon Mining Landscape World Heritage Site, sit on what's called Article 1(5) land. Permitted development rights — the free pass that lets many homeowners skip planning permission altogether — are restricted there. Whether your property is affected isn't always obvious, even if you think you know your area.

What the fee calculator won't tell you

The official planning fee calculator will confirm your application fee. What it won't tell you is whether your project is likely to be approved, what supporting documents Cornwall Council will require, or how similar projects nearby have fared.

That's the expensive part — not knowing. Submitting an application that gets refused means losing your fee and starting again. Spending on plans and reports for a project that was never going to fly costs far more than the application fee ever would.

WhatCanIBuild shows you what's actually been approved and refused for similar projects near your address — including the reasons why — so you can understand your real odds before you spend a penny on professional fees.

The typical decision time in Cornwall is 8 weeks. But getting to a decision you're happy with, on a project that's properly prepared? That timeline depends on choices you make before you even submit. WhatCanIBuild gives you the property-specific picture that no fee calculator can.