Free early-stage checks

UK planning calculators and site tools.

Fifteen practical screening tools for homeowners, landowners and small developers. Check planning routes, development constraints, application costs and design considerations before commissioning detailed work.

Explore the tools Discuss a project

Choose a planning question.

Every result is calculated in your browser except postcode screens, which query public UK datasets through the Hepburn Architects site. No postcode is stored by these tools.

Flood-zone postcode screen

Check whether a postcode point intersects the available national flood-risk planning dataset.

Point-based screen only. Confirm the full red-line boundary and surface-water risk on official maps.

Flood-zone compatibility checker

Screen a proposed use against the broad NPPF vulnerability approach.

Flood zone Proposed use

Air Quality Management Area checker

Check whether a postcode point intersects a published AQMA boundary.

Heat pump versus gas carbon

Compare annual operational carbon using SAP 10.2 compliance factors.

Annual gas use (kWh) Boiler efficiency (%) Heat pump SCOP

Air-source heat pump planning checker

Screen the principal householder permitted-development conditions in England.

Property Outdoor unit Units after installation MCS noise assessment

Planning application checklist

Create an indicative document list from the main national validation triggers.

Proposal Site area Within 20 m of watercourse Nearby neighbour windows

Planning application fee estimator

Estimate common English planning fees effective from April 2026; confirm the amount before submission.

Application route Homes / units where relevant

National space standard checker

Look up the minimum gross internal area for common dwelling sizes.

Bedrooms Bed spaces Storeys Main washing facility

Use-class change checker

Identify whether a change is generally internal to a class, may use prior approval, or needs planning permission.

Current use Proposed use

Planning decision deadline

Calculate headline 8, 13 or 16-week determination dates.

Validation date Application type

Do I need a flood-risk assessment?

Screen the main national triggers for a site-specific FRA.

Flood zone Site area Within 20 m of a watercourse Known local flooding Change to a more vulnerable use

Site constraints appraisal

Screen a postcode point against available national planning designations.

House extension permitted-development checker

Screen key Class A extension and Class E outbuilding limits without mixing the two height rules.

Property Designated land / Article 4 Proposal Depth beyond rear wall (m) Overall height (m) Eaves height (m) Within 2 m of a boundary More than 50% curtilage coverage

Green Belt postcode checker

Check whether a postcode point intersects England’s published Green Belt dataset.

Find the local planning authority

Use a UK postcode to identify the council, ward and region.

Important

Screening results are a starting point.

These tools provide general information for projects in England. They do not confirm planning permission, legal rights, site boundaries or technical compliance. Local policy, Article 4 directions, listed status, site-specific evidence and later regulatory changes can alter the answer.

Planning application support