Rear kitchen extension interior in a Monken Hadley conservation area house, EN5, London Borough of Barnet

Monken Hadley · EN5 · Barnet

Rear Extension Drawings in Monken Hadley EN5

Fixed-fee, MCIAT-chartered rear extension drawings for Monken Hadley (EN5) homeowners — London Borough of Barnet validation and local constraints handled from the start.

Monken Hadley is the historic common-edge village at the top of EN5, on the Barnet side of the Enfield boundary, with Georgian and Victorian houses gathered around Hadley Green. Projects here are usually careful rear extensions, garden rooms or internal reworking that keep the period frontages intact.

The Monken Hadley Conservation Area and its Article 4 Direction cover many houses around the green and common, and a number are listed. We check the conservation-area boundary, listing status and Article 4 scope before advising whether anything can proceed as permitted development or needs a full planning and heritage submission.

Proposed floor plan

Monken Hadley EN5

Monken Hadley (EN5) — planning at a glance

Council: London Borough of Barnet
Postcode district: EN5
Planning portal: View the Barnet planning portal
Housing stock: Georgian and early-Victorian houses and cottages ranged around Hadley Green and the common, many listed, alongside later Victorian villas. Brick and render frontages, sash windows and long rear gardens are typical.
Article 4: Barnet's Monken Hadley Article 4 Direction removes householder permitted development over many houses around the green and common, so even modest external changes need planning permission.
Conservation: Monken Hadley Conservation AreaWood Street Conservation Area
Sample streets: Hadley Green Road · Hadley Common · Dury Road · Bakers Hill
Local constraints: Monken Hadley Conservation Area protects the historic village setting around the green, with many houses individually listedAn Article 4 Direction removes permitted development over many properties, so even small external works need planning permissionMonken Hadley Common and the surrounding Green Belt limit how far extensions can extend on plots backing onto open land

Planning in Monken Hadley (EN5): what to know before you apply

Most external work in Monken Hadley needs full planning permission with a heritage statement, because the conservation area and Article 4 Direction remove permitted development and many houses are listed. Where a property is listed, separate listed building consent is also required for internal and external alterations.

Typical Monken Hadley housing stock

Georgian and early-Victorian houses and cottages ranged around Hadley Green and the common, many listed, alongside later Victorian villas. Brick and render frontages, sash windows and long rear gardens are typical.

Streets we regularly draw for in Monken Hadley

Hadley Green Road · Hadley Common · Dury Road · Bakers Hill

What EN5 is actually built of

Measured from 438 classified residential buildings in EN5, not from a description of the area.

Monken Hadley EN5 housing mix

Residential building form across the EN5 postcode district, from 438 classified buildings.

Attached on more than one side	25%
Attached on one side	55%
Detached	20%
Median building footprint	73 m²
Addresses per buildingAbove about 2 means flats and maisonettes dominate	1.99
Buildings classified	438

Source: Ordnance Survey National Geographic Database (derived statistics). Contains OS data © Crown copyright and database right 2026. Contains Royal Mail data © Royal Mail copyright and database right 2026. Extracted 2026-08-17.

Rear Extension Drawings for Monken Hadley (EN5) homes: the package and the process

Depth is the number the application turns on, and it has to be measured from the original rear wall of the house rather than from whatever is there now. The drawings carry that dimension, the eaves and ridge heights, the position of any rooflight, and the boundary distances on both sides.

Where the scheme goes beyond the standard allowance and relies on the larger home extension route, the drawings serve a second purpose: they are what the council sends to the neighbours during the consultation. A clear, dimensioned proposed elevation answers the objection about overshadowing before it is made.

Depth is limited by the plot as much as by the rules. A long garden behind a terrace can take the full allowance, while a short one runs out before the rules do — and on a semi or detached house the same depth reads very differently from the boundary.

Do I need planning permission for a rear extension in London?

Many single-storey rear extensions qualify as permitted development, meaning no planning application is needed, provided depth, height and materials stay within set limits. That changes if your property sits in a conservation area or is subject to an Article 4 direction, both of which can remove permitted development rights across a street or borough — in that case a full householder planning application is required regardless of size.

Even where an extension qualifies, most homeowners obtain a Lawful Development Certificate to confirm that status in writing before building — useful for mortgage lenders, buyers and Building Control. We check your property against your borough's constraints before recommending a route.

How deep can a single-storey rear extension go?

Depth is the main constraint on a rear extension, and it depends on your house type and whether you use standard permitted development or the larger home extension scheme.

Permitted development

Standard permitted development allows a single-storey rear extension up to 3 metres deep for terraced and semi-detached houses, or 4 metres for detached houses, generally with eaves height limited to match or stay close to the existing house.

Larger home extension scheme

The prior-approval scheme extends this to 6 metres for terraced and semi-detached houses and 8 metres for detached houses. Your council writes to affected neighbours; if none object within the notification period, approval follows without a full planning application. If an objection is raised, the council assesses the impact on neighbouring light and outlook itself, rather than automatically refusing, so a well-considered design still has a good chance of approval.

Designing the kitchen-diner: rooflights, bi-folds and daylight

Most rear extensions exist to create one open-plan kitchen, dining and living space, so the drawing work focuses on getting light and flow right within the depth you are allowed.

Structural opening sized for bi-fold or sliding doors across most of the rear elevation
Rooflights or a roof lantern positioned to light the centre of the room, away from the shadow line of the main house
Open-plan layout tested against the 45-degree rule, which protects daylight to your neighbours' windows and can limit how close a flank wall or roof comes to the boundary
Floor build-up and threshold detail coordinated so the new floor meets the existing one without a step

Rear extension routes at a glance
Route	When it applies	Typical fee
Permitted development (Lawful Development Certificate)	Depth within 3m (terraced/semi) or 4m (detached), height and materials within PD limits	PD/LDC pack ~£950–£1,450
Larger home extension (prior approval)	Depth up to 6m (terraced/semi) or 8m (detached), with neighbour notification	from £1,100
Full householder planning permission	Extension exceeds PD/larger-home limits, or the property is in a conservation area with an Article 4 direction	Full Planning pack ~£1,600–£2,400
Planning + Building Regulations (structural)	Combined planning and construction-ready pack with structural calculations for the opening and roof	Planning + Building Regs pack ~£2,200–£3,850

Sheet from a rear extension drawings package drawn for a Monken Hadley property in EN5, showing the existing and proposed arrangement at scale — A sheet from the rear extension drawings package we submit to London Borough of Barnet for Monken Hadley (EN5) properties.

Also in Monken Hadley EN5

Planning Permission Planning Drawings Architectural Drawings Building Regulations Drawings Loft Conversion Drawings Rear Extension Drawings across Barnet Rear Extension Drawings across London

FAQ

Rear Extension Drawings in Monken Hadley EN5 — FAQs

How much does a rear extension cost to design in London?+

Rear extension drawings start from £1,100, with the final fee set by the route your extension takes — permitted development, prior approval or full planning — and whether you need building regulations and structural calculations bundled in. The fee is fixed and agreed upfront.

Do I need an architect for a rear extension?+

No. DrawingsDirect is an MCIAT-chartered architectural technologist practice, producing the same council-accepted drawings as an architect for a fixed fee typically around 30% lower.

How long does it take to get rear extension drawings?+

Drawings are typically ready around 7 days from survey. Once submitted, councils have a statutory 8-week period to determine a standard householder planning application.

What is the 45-degree rule?+

It is a daylight test many London councils apply to check that a rear extension does not block too much light to a neighbour's nearest window, measured as a line drawn at 45 degrees from that window. We check it before submission, not after a refusal.

Will I need a Party Wall Agreement for a rear extension?+

Only if your foundations or new walls sit on or near the boundary with a neighbouring property. A straightforward rear extension set within your own plot often does not trigger the Party Wall etc. Act 1996, unlike a Side Return or Wraparound extension, which usually does.

Do I need planning permission for a loft or extension in Barnet?+

Across Finchley, Edgware and Hendon, Barnet's 1930s semis usually keep permitted development rights for rear extensions and hip-to-gable or dormer lofts, so a full application isn't always needed. The major exception is Hampstead Garden Suburb, where an Article 4 direction removes almost all permitted development rights. We check your address first and confirm permitted development with a Lawful Development Certificate where it applies.

What is different about building in Hampstead Garden Suburb?+

The Suburb has one of the most far-reaching Article 4 directions in London: almost all external alterations need planning permission, and the Hampstead Garden Suburb Trust must also consent to changes in parallel with the council. We handle both tracks — a carefully evidenced planning application to Barnet and the Trust's design requirements — since approval there depends on respecting the Arts-and-Crafts character precisely.

Is a hip-to-gable loft conversion allowed on my Barnet semi?+

Usually, yes. The borough's abundant interwar semis are well suited to hip-to-gable and dormer conversions, which frequently qualify as permitted development on semi-detached homes within the volume limits. Outside conservation areas and the Suburb, this is often the quickest route. We confirm eligibility, then produce the planning and building-regulations drawings.

How long does Barnet take to decide an application?+

Barnet determines most householder applications within the statutory eight-week period once validated; Suburb and conservation cases can involve additional consultation. We prepare Barnet submissions to the validation checklist, with the elevations and materials detail the council expects, to avoid the drawing queries that are the usual cause of delay.

How much do Barnet planning drawings cost?+

We agree a fixed fee before we start, typically around 30% below an architect's fee for the same council-accepted drawings, with free redraws until Barnet approves. A straightforward Finchley loft and a Hampstead Garden Suburb application differ in the evidence required, so we quote once we have seen the project and know which route applies.

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