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Planning application

39 Cornwall Avenue London N3 1LG

Awaiting decision Barnet 25/5142/192 Proposed Lawful Development Certificate

Works: Extension Loft or dormer Windows or glazing

Still open. Anyone can comment while the consultation period runs, and comments go to the council rather than to us.

Proposal

Roof extension involving hip to gable, rear dormer window and 3no. front facing rooflights

As published by the council, reference 25/5142/192

Application record

Reference
25/5142/192
Type
Proposed Lawful Development Certificate
Status
Pending Decision
Received
22 Dec 2025
Validated
22 Dec 2025
Ward
West Finchley
Postcode
N3 1LG

Site history

Applications at this address on the Barnet register

This site has had 3 applications since 2025.

  • 26/3192/HSE Decided

    39 Cornwall Avenue London N3 1LG

    New front porch (amended plans)

    Submitted 1 Sep 2026 Householder
  • 25/3818/HSE Awaiting decision

    39 Cornwall Avenue London N3 1LG

    Single storey rear extension. Conversion of the existing garage into habitable room, insertion of window to replace the garage door

    Submitted 17 Sep 2025 Householder

Timeline

Dates from the published record

  1. 22 Dec 2025

    Received by Barnet

  2. 10 Aug 2026

    Added to PlanIndex

  3. Decision

    Awaiting decision

    Decision expected by 16 February 2026, 8 weeks from validation under the statutory target for most applications. Extensions of time are common and are agreed case by case.

    Barnet took a median of 46 days over the applications it decided in the last year.

Who's behind it

Company information only, from the register and Companies House

Mehra Designs Agent, a design practice

4 applications on PlanIndex · across 3 councils

Trade members see everything this firm has filed, how it was decided, and get an email the day it files again.

See their track record

Documents

Plans, drawings, consultee responses and the officer's report

7 documents on file for this application

A planning file usually holds the application form, drawings and site plans, consultee responses, the officer's report and the decision notice.

Watch members (£5 a month) open the document list from here.

Open the documents

What happens while it is decided

This application is with Barnet for determination, against a statutory target of eight weeks. Over the last year Barnet decided lawful development applications in a median of 28 days. More in our guide to how long planning decisions take.

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

  • 39 Cornwall Avenue London N3 1LG

    25/3818/HSE Submitted 17 Sep 2025 50 yards away

    77% historically approved · decision due ~12 Nov

    Single storey rear extension. Conversion of the existing garage into habitable room, insertion of window to replace the garage door

    Awaiting decision Householder Extension Windows or glazing 9 docs
    Small domestic

  • 37 Cornwall Avenue London N3 1LG

    25/4558/FUL Submitted 14 Nov 2025 50 yards away

    Conversion of the existing dwelling into 2no. self-contained flats including single storey rear extension with green roof and parapet, front porch infill, first floor rear terrace area with obscure glazing, roof extension involving rear dormer window and 4no. front facing rooflights

    Refused Full applications New dwelling Extension +2 12 docs
    Small domestic

  • 37 Cornwall Avenue London N3 1LG

    26/0945/HSE Submitted 12 Mar 2026 50 yards away

    Single storey rear extension following demolition of the existing sun room. Roof extension involving rear dormer windows and 4no. front facing rooflights

    Granted Householder Extension Loft or dormer +2 13 docs
    Small domestic

  • 39 Cornwall Avenue London N3 1LG

    26/3192/HSE Submitted 1 Sep 2026 50 yards away

    77% historically approved · decision due ~27 Oct

    New front porch (amended plans)

    Decided Householder Extension
    Small domestic

  • 32 Cornwall Avenue London N3 1LG

    26/2627/191 Submitted 14 Jul 2026 50 yards away

    79% historically approved · decision due ~1 Oct

    Conversion of part of the 1st floor and 2nd floor to create 1no. self-contained residential dwelling (Use Class C3)

    Awaiting decision 18 docs
    Domestic

  • First Floor Flat 33 Grove Avenue London N3 1QS

    26/0556/FUL Submitted 12 Feb 2026 50 yards away

    Change of use of the upper floor flat (Class C3) to a 3 bed House in Multiple Occupation (HMO) (Class C4). Associated refuse/recycling and cycle storage (AMENDED DESCRIPTION)

    Refused Full applications 15 docs

In Barnet

  • 26/2679/192 Granted

    21 Myddelton Park London N20 0JH

    Single storey rear extension and increase in ridge height of existing rear outrigger (Amended description).

    Received 20 Jul, published by the council 7 Aug 2026 Lawful development
  • 26/1362/191 Refused

    145 Cotswold Gardens London NW2 1PL

    Use as a House in Multiple Occupation (HMO) for 6 people

    Received 14 Apr, published by the council 25 Jul 2026 Lawful development
  • 26/1907/191 Granted

    8 Golders Manor Drive London NW11 9HT

    Use of the property as a self-contained residential unit at ground floor level and the first and second floors as a 4-bedroom, 4-person House in Multiple Occupation (Sui Generis) (AMENDED DESCRIPTION)

    Received 21 May, published by the council 16 Aug 2026 Lawful development
  • 26/2392/192 Refused

    6 Mostyn Road Edgware HA8 0JD

    New front hardstanding and vehicular access to provide off-street parking

    Received 23 Jun, published by the council 9 Aug 2026 Lawful development
  • 26/2059/192 Refused

    Low Ridge Rowley Lane Barnet EN5 3HS

    Erection of a rear outbuilding

    Received 3 Jun, published by the council 16 Aug 2026 Lawful development