Calculators
Free tools to help you plan and budget your UK kitchen extension.
Cost & planning calculators
Extension Cost Estimator
Get a ballpark cost for your kitchen extension based on size, location, and specification.
Professional Fees Calculator
Estimate architect, structural engineer, building control, and other professional fees for your extension.
Timeline Estimator
Estimate how long your kitchen extension will take from planning to completion.
Payment Schedule Generator
Generate a suggested milestone payment schedule for your extension project.
Decision tools
Do You Need Planning Permission?
Answer a few questions about your property and proposed extension to find out whether you need planning permission, can use permitted development, or may qualify for prior approval.
Permitted Development Limit Checker
Enter your extension dimensions to check each PD condition individually. See which limits you pass, which you fail, and what your options are.
Do You Need a Party Wall Notice?
Check whether your extension triggers the Party Wall Act 1996. Answer questions about your walls, boundaries, and foundation depth to find out which sections apply.