Permitted Development Extensions in Swansea Council

Maximum extension sizes without planning permission, applied to Swansea Council (Wales). The English route for this strategy does not apply here; see below for what to do instead.

A row of traditional Georgian-style terraced houses with brick facades and white window surrounds under a blue sky — Georgian-style terraced housing, illustrative of UK residential architecture. Image is illustrative, not location-specific.Photo via Unsplash

Reviewed by the Scapely editorial team on 23 October 2026 2026-10-23

This England-only route does not apply in Wales

The householder and other permitted development allowances people quote online come from the English General Permitted Development Order. Wales has its own, different order and limits, so English size limits must not be used here.

What to do instead: Speak to the local planning authority about pre-application advice and submit a full application under Welsh planning policy. Check the Welsh permitted development order for any right that fits, rather than English rules.

Checklist: Permitted Development Extensions

Confirm the house still has its permitted development rights (not flats, not previously used up, no Article 4 direction).
Measure against the current rules for the nation you are in; do not reuse English limits elsewhere.
Check conservation area, listed status and Article 4 restrictions on the address.
Consider a lawful development certificate to prove the position.
Check neighbour consultation and prior approval requirements for larger extensions.

Article 4 and local designations

Article 4 directions apply to defined areas and to specified rights, not to a whole council. Whether one covers a property can only be confirmed from the council's direction map or by asking the council. Scapely's regional indicator is a screening prompt only.

Building safety triggers

Wales has its own building safety and building control arrangements. The English higher-risk building gateways do not apply directly. Check with the local building standards or building control authority.

Finding Swansea's official records

Use the Wales planning sources below. Do not use English datasets or English permitted development rules for Wales.
Confirm any article 4 or equivalent direction, conservation area and listed status on the council's own maps or by asking the council.
Find Swansea Council's adopted local plan or development plan on the council's own website and note site allocations and housing policies.
Search the council's online planning register for the address and nearby schemes. Recent decisions and officer reports show how policy is applied in practice.
Ask the planning team about pre-application advice, and what it costs, before committing money to design.
Check the council's CIL charging schedule, if it has one, and its approach to S106 obligations.

Indicative build cost

Screening benchmark: about £1850/sqm. Build-cost and market figures on this page are indicative Scapely editorial benchmarks used for screening. They are not quotes, valuations or live data, and they have not been checked against a cost consultant. Real costs vary with specification, access, scale and date.

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A working sample of the Scapely Dashboard. Search the three sample properties, jump between report sections and stress-test costs and strategies. Everything here is sample data running in your browser.

Sample data

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Samples

Property report (sample)

24 Coleherne Road

Score 67/100

SW10 9BWRoyal Borough of Kensington and ChelseaMid-terrace house6 rooms152 sqmPre-1900

Quick stats

EPC rating, transport access, HMO density and flood risk at a glance.

EPC Rating

Potential C with works.

EPC band E (SAP 48). Potential band C with the modelled works.

PTAL Score

Excellent

Excellent. Public Transport Accessibility Level from TfL where available.

HMO Density

14%

Moderate saturation.

Moderate HMO saturation in the surrounding area.

Flood Risk

Zone 1

low probability of flooding.

Environment Agency Flood Zone 1: low probability of flooding.

Sale history

Registered transactions and nearby comparables to benchmark the price.

Last registered sale

£1,850,000

Comparable average

£1,736,667

Comparables vs last sale

-6.1%

18 Coleherne Road£1,975,000
8 Feb 2024
31 Coleherne Road£1,690,000
14 Sept 2022
9 Coleherne Road£1,545,000
3 Nov 2021
24 Coleherne RoadSubject£1,850,000
12 Apr 2019
24 Coleherne RoadSubject£1,420,000
6 Jul 2011

Sample records styled on HM Land Registry Price Paid Data. Not real transactions.

Property fundamentals

Heritage, tenure and neighbourhood deprivation shape consent and buyer appetite.

Deprivation

Decile 7

Index of Multiple Deprivation, 1 = most deprived, 10 = least.

MostLeast

England's IMD ranks every neighbourhood from most to least deprived.

Area information

Kensington and Chelsea 012B. Urban conurbation, high-value Victorian terraces and strong rental demand.

Royal Borough of Kensington and ChelseaMid-terrace house152 sqmPre-1900

Heritage status

Conservation Area

Not listed, but alterations in a Conservation Area need full planning consent.

Listing and conservation designations restrict alterations.

Tenure

Freehold

Full ownership, no lease or ground rent liabilities.

Freehold means outright ownership of the building and land.

Local authority

Sample

Royal Borough of Kensington and Chelsea

The authority whose planning policy applies to this plot.

Energy performance

Current rating and the cost and uplift of upgrading before selling or letting.

EPC uplift potential

Current

Headroom

+2 bands

Potential

SAP score moves from 48 to 79 with the modelled works.

Retrofit cost

£22,400

£18,200 to £28,600

Indicative spend to reach the potential band.

Capital uplift

+6.5%

Greener-homes value premium per band achieved.

Rental uplift

+4.2%

Estimated rent premium per band achieved.

Annual bill saving

£1,840/yr

£3,120 to £1,280

Heating, hot water and lighting after improvements.

Air source heat pump£8,000 to £14,000saves £720/yr
Solid wall insulation (external)£9,000 to £15,000saves £540/yr
Secondary glazing£1,200 to £3,500saves £180/yr

Development potential

Planning risk, recommended route and a first-pass screen of permitted development rights.

Recommendation

Target strategyExplore refurbishment or a 4-bed HMO, subject to planning permission

Planning risks · Sample: not a higher-risk building (low-rise house)

Overall riskMedium

Illustrative sample only. It assumes Conservation Area and Article 4 restrictions that limit permitted development. Extensions may need planning consent. Where an Article 4 direction removes C3 to C4 rights, an HMO conversion requires a planning application, not prior approval.

Key objection themes

Conservation Area characterArticle 4: HMO restrictionsNeighbour amenityHeritage materials policy

C3 to C4 HMO conversion

Part 3, Class L

Restricted

Sample Article 4 restriction: planning permission required for C3 to C4 conversion.

The sample assumes an Article 4 direction removes Class L permitted development rights.
Apply for planning permission; prior approval does not replace removed permitted development rights.

Rear extension

Part 1, Class A

Restricted

Up to 3m permitted in principle, subject to Conservation Area materials criteria.

Materials must match original Victorian stock.
Anything above eaves height needs full consent.

Additional storey

Part 1, Class AA

Not available

Not available within a Conservation Area.

Class AA rights do not apply in designated Conservation Areas.

Sample first-pass screen. The live Dashboard checks the real constraints for any address.

Commercial and levies

Class MA, CIL, MEES and biodiversity net gain obligations.

Class MA

Not eligible

Residential (C3). Class MA applies to commercial Class E only.

PD right to convert commercial premises to homes.

CIL Zone 3

£125/sqm

Verify against the current charging schedule.

Community Infrastructure Levy on new floorspace.

Commercial MEES

Check

Sample EPC E. Commercial lets in England and Wales currently need at least EPC E, with exemptions. Domestic rules are separate, and proposed changes are not yet law.

Current rented non-domestic EPC rules in England and Wales are separate from proposed future standards. Check exemptions, use and jurisdiction.

BNG

Low

Existing residential: negligible obligation unless adding new footprint.

Biodiversity Net Gain: a measurable 10% habitat improvement.

Sample data for demonstration only. No searches, payments or accounts are used here.Run a real report in the Dashboard

How the Dashboard helps

The paid Dashboard screens a specific address, including the AI Objection Risk Analyzer. It does not replace checking the council's own records or taking advice from a planning consultant.

Sources and methodology

Reviewed by the Scapely editorial team on 23 October 2026.

Swansea Council: official council website (Use the council's planning section to find its application register, adopted plan, policy maps and applicable directions. This link does not verify a site's permissions.)
Welsh Government: planning
Planning Portal
GOV.UK: non-domestic private rented property MEES landlord guidance (current law)

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