Planning application
4 Lon-y-deri Caerphilly CF83 1DS
Works: Extension
Permission granted. Work must normally begin within five years of the decision or the permission lapses.
Proposal
Obtain Certificate of Lawful Proposed Development for extension to side and rear of property
As published by the council, reference 26/0423/CLPU
Application record
- Reference
- 26/0423/CLPU
- Type
- Certificate Lawful Proposed Use/Dev
- Status
- Decided
- Decision
- Granted
- Received
- 17 Jun 2026
- Validated
- 29 Jun 2026
- Decided
- 18 Aug 2026
- Ward
- St Martins
- Decision by
- Delegated
- Postcode
- CF83 1DS
Site history
Applications at this address on the Caerphilly register
This site has had 2 applications since 2025: 2 approved, 0 refused.
-
25/0846/CLPU Granted
4 Lon-y-deri Caerphilly CF83 1DS
Obtain Certificate of Lawful Proposed Development for extension to side and rear of property
Timeline
Dates from the published record
-
17 Jun 2026
Received by Caerphilly
-
29 Jun 2026
Validated
Checked as complete and ready for consideration.
-
28 Jul 2026
Added to PlanIndex
-
18 Aug 2026
Decision issued: Granted
Who's behind it
Company information only, from the register and Companies House
Williams Architectural Design Agent, an architecture practice registered in Darwen
Active · incorporated 2024 · Darwen
14 applications on PlanIndex · across 2 councils · 79% granted
Trade members see everything this firm has filed, how it was decided, and get an email the day it files again.
See their track recordDocuments
Plans, drawings, consultee responses and the officer's report
8 documents on file for this application
- DECISION
- DELEGATED REPORT
- DECISION PLAN
- EXISTING LAYOUTS AND SITE LOCATION PLAN
- SUPPORTING STATEMENT
- APPLICATION FORM
- PROPOSED LAYOUTS
- APPROVED PROPOSED LAYOUTS FOR 25/0846/CLPU
Watch members (£5 a month) open the document list from here.
Open the documentsWhat this grant of permission means
Caerphilly granted permission on 18 August 2026, subject to any conditions on the decision notice. Work must normally begin within five years or the permission lapses. More in our guide to what happens after a planning decision.
About lawful development applications
A lawful development certificate is a legal determination that existing or proposed works do not need planning permission; the merits of the scheme are not considered. More in our guide to planning application types.
Nearby applications
Within 0.3 miles
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4 Lon-y-deri Caerphilly CF83 1DS
Obtain Certificate of Lawful Proposed Development for extension to side and rear of property
Granted Lawful development Extension 7 docs -
8 Lon-y-waun Caerphilly CF83 1DQ
76% historically approved · decision due ~7 Oct
Remove existing conservatory and erect a single storey rear extension including internal alterations
Awaiting decision Householder Extension 6 docsSmall domestic -
Moruzzi Landscapes Limited Nantgarw Road Caerphilly CF83 1BW
Erect security fencing & automated gate to site frontage with Nantgarw Road
Granted Full applications 9 docs -
24 Lon Uchaf Caerphilly CF83 1BR
Erect front elevation bay window
Refused Householder Windows or glazing 8 docsDomestic -
PHS Group Ltd Block B Western Industrial Estate Caerphilly CF83 1XH
77% historically approved · decision due ~3 Nov
Obtain a Lawful Development Certificate for installation of 140 No. roof-mounted photovoltaic solar panels on the east-, south- and west-facing pitched roof slopes of the existing commercial building, providing a total installed generating capacity of approximately 85.4 kWp, together with associated inverter, mounting system and ancillary electrical infrastructure
Awaiting decision Lawful development 9 docs -
18 St Julian's Court Caerphilly CF83 1DN
Erect two storey and single storey side extensions
Granted Full applications Extension 8 docsSmall domestic
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26/0548/CLEU Granted
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Obtain a Lawful Development Certificate for existing use of the land as garden area associated with No. 9 St Davids Park
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26/0635/CLEU Awaiting decision
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Obtain a Lawful Development Certificate for existing use of the whole premises as a non-residential hall for community, meeting, educational and training purposes, falling within Class D1
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26/0517/CLPU Refused
26 Heolddu Crescent Bargoed CF81 8UQ
Obtain a Lawful Development Certificate for the proposed use of one of the existing ground floor rooms as a small-scale home-based tattoo business
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26/0611/CLPU Awaiting decision
24 Heol Cwarrel Clark Caerphilly CF83 2NE
Obtain a Lawful Development Certificate for conversion of the existing integral garage into habitable accommodation, replacement of the garage door with a window, associated internal alterations and installation of a compact through-floor lift
-
26/0598/CLPU Awaiting decision
PHS Group Ltd Block B Western Industrial Estate Caerphilly CF83 1XH
Obtain a Lawful Development Certificate for installation of 140 No. roof-mounted photovoltaic solar panels on the east-, south- and west-facing pitched roof slopes of the existing commercial building, providing a total installed generating capacity of approximately 85.4 kWp, together with associated inverter, mounting system and ancillary electrical infrastructure