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
13 applications on PlanIndex · across 2 councils · 77% 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
Trade members open them 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 500 metres
-
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
77% 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 -
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 -
Rosary Cottage Lon-Y-Llyn Caerphilly CF83 1BY
Erect single story rear extension
Granted Full applications Extension 12 docs
Other lawful development applications
In Caerphilly
-
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.
-
26/0583/CLEU Awaiting decision
Gavel Holdings Limited Gelligroes Mill Road Pontllanfraith Blackwood NP12 2HY
Obtain a Certificate of Lawfulness for existing use of Classes B1 (Business), B2 (General Industrial) and B8 (Storage or Distribution).
-
26/0582/CLPU Awaiting decision
41 Blacksmith Close Oakdale Blackwood NP12 0BG
Obtain a Lawful Development Certificate to erect single-storey rear extension to the existing dwellinghouse
-
26/0579/CLPU Awaiting decision
The Barn Pen Y Caeau Farm Abercarn Mountain Road Hafodyrynys Newport NP11 5AY
Erect single-storey timber stable block within the existing residential curtilage of the dwelling,
-
26/0518/CLPU Granted
2 Rhyd Y Gwern Lane Draethen Newport NP10 8GH
Obtain a Lawful Development Certificate to erect a timber boundary fence 2m high to east elevation to include 2m vehicular gates to private right of way, and 2m timber boundary fence to west elevation (reduced to 1m in height 2m set back from highway)