AI Permitted Development Calculator

Layer national PD rules, Article 4 directions, heritage overlays, and finance hooks in a single guided flow. The output streams straight into your Deal Profile.

AI-Powered

Free to use

1PD AssessmentPD

2GDV EstimateGDV

3Build CostsBuild

4FinanceFinance

Guidance

What to prepare

We only need a handful of fields to qualify PD routes and trigger Construction Capital review.

Confirm the current use class + tenancy.
Flag Article 4, conservation, or flood zones.
Provide gross internal area and intended storeys.
Share your target units for GDV projections.

Site inputs

These values are stored inside the Deal Profile.

AI RECOMMENDATION

AI Development Summary

Ready

Live

Provide the site address, current use class, and your conversion target. The PD calculator will layer Article 4 directions, heritage data, and flood zones to recommend the fastest compliant route.

PD ROUTE

Class MA permitted

REVIEW SLA

Instant + auto-send to finance

Confidence92%

Gross development value

£6,310,933

Based on comps & density

Build cost baseline

£1,459,600

-2.1%

QS baseline incl. contingencies

Loan-to-cost

72%

Expected senior lending appetite

About the Permitted Development Calculator

What it does and how it helps you

The Permitted Development Calculator helps UK property developers assess PD rights and conversion opportunities. Evaluate Article 4 directions, heritage overlays, and planning routes for office-to-residential and commercial-to-residential conversions.

Article 4 direction checking and planning route recommendation

Heritage and conservation area overlay assessment

Class MA and Class O PD rights evaluation

Preliminary GDV and build cost estimates for quick viability

How It Works

Understanding the calculation method

The Permitted Development Calculator assesses PD viability: 1. Site Details - Enter address, local authority, existing use class, and proposed use 2. Planning Constraints - Flag Article 4 directions, conservation areas, and heritage restrictions 3. Development Metrics - Input GIA, storeys, target units, and market values 4. PD Route Assessment - Determines if scheme qualifies for Class MA (office to resi), Class O (commercial to resi), or requires full planning 5. Viability Metrics - Calculates estimated GDV, build costs, and finance leverage 6. Deal Profile - Saves assessment to deal context for ongoing tracking The calculator provides recommended planning route, indicative costs, and finance appetite assessment.

When to use this calculator

Use this calculator during site sourcing and initial appraisal to determine if PD rights apply. Essential before making offers on commercial buildings. Helps filter opportunities quickly and identify red flags (Article 4, heritage constraints) before incurring professional fees.

Frequently Asked Questions

Common questions about this calculator

Permitted Development (PD) allows certain changes of use without full planning permission. Key classes: Class MA (office/light industrial to residential up to new build size), Class O (office to residential - now expired in most areas), and various extensions/alterations. PD offers faster consent (typically 8-12 weeks vs 8-13 weeks for full planning) and avoids S106/affordable housing. However, prior approval still required assessing transport, contamination, flooding, and design.

Article 4 Directions remove specific PD rights in defined areas. Common in conservation areas, town centres, and residential areas. Local authorities use Article 4 to control conversions they consider harmful (e.g., loss of office space, poor quality housing). Always check local authority planning portal - Article 4 means you need full planning permission. Many London boroughs have Article 4 on office-to-residential conversions.

Sometimes yes, sometimes no. Conservation area designation alone doesn't block PD, but most conservation areas have Article 4 directions removing PD rights. You can still apply for full planning permission, but standards are stricter - heritage impact, materials, design quality, and amenity space all scrutinised. Prior approval route might work if no Article 4 applies, but local planning authority has stronger grounds to refuse based on design.

Key restrictions: 1) Building must have been in qualifying use for at least 2 years before application, 2) Site must not be in area with Article 4 direction, 3) Maximum floorspace limits apply (varies by class), 4) Cannot demolish and rebuild - only convert existing structure, 5) External alterations limited, 6) Minimum space standards apply (37-61sqm depending on unit size), 7) No permission for change of use if building is listed.

Usually yes, but not always. PD prior approval determination: £334 for most schemes, 8-12 weeks decision period (but often takes longer). Full planning: £462 per unit plus £22,859 if over 50 units, 8-13 weeks statutory (often extends). However, PD still requires: transport assessment, contamination report, flood risk assessment, noise assessment. Total professional fees: £15k-£30k for PD, £30k-£60k+ for full planning on similar scheme. Main saving: no affordable housing or S106.

Related Property Terms

Permitted Development rights UKOffice to residential conversionClass MA prior approvalArticle 4 Direction checkCommercial to residential PDPrior approval calculatorConservation area PDChange of use permitted developmentPD viability calculatorGPDO Class MA