Area guide · EN5
House Extensions in Monken Hadley (EN5)
Thinking about extending a house in Monken Hadley? This is a historic village of Georgian and earlier houses gathered around Hadley Green and the church, with the common and rolling green belt behind. The projects here are individual and often substantial. Extending in the Monken Hadley conservation area is a design discipline of its own, listed buildings and protected views included, and it is exactly the kind of work we relish: sensitive, high-specification schemes, the substantial ones, taken through Barnet Council with the conservation case built in from the first sketch.
Planning in Monken Hadley
What Barnet is approving, and how the conservation lens changes it
Monken Hadley sits within the London Borough of Barnet, in its High Barnet ward, and the newest decisions for that ward are listed with dates and references on our Barnet page. The ward takes in the village as well as the town centre and Arkley, so its decisions are the nearest local record for Monken Hadley, everyday rears and lofts included.
The conservation area is also wider than the village. It follows the common east as far as Games Road on the Cockfosters side, and it takes in Latimer Road and The Crescent on the New Barnet side, so houses that feel suburban can still be inside it.
Inside the conservation area the same schemes are judged through a second lens: preservation or enhancement of the area's character. In practice that means materials matched to the historic fabric, additions that defer to the original house, and rooflines left legible. It does not mean nothing gets approved; it means the design does the persuading. Behind a Georgian frontage on Hadley Green Road or Camlet Way, a well-composed rear addition, a discreet garden building or a basement that never shows itself to the street are all winnable consents, and they are the projects our luxury extensions service was built for.
Local knowledge
The village's stock, green by green
Monken Hadley is small and the houses are individual, which is rather the point. Four situations cover most briefs.
The Georgians on the green. The set-piece houses around Hadley Green are the village's crown, many of them listed. Work here is measured: walled-garden rear additions with true sash joinery and lime-right brickwork, and interiors reworked behind protected fronts. Listed building consent joins the planning application where it applies, and we manage both.
Camlet Way and the lanes. Substantial period and Victorian houses on generous plots. The Barnet end of Camlet Way is inside the conservation area and the green belt; further east the road crosses into Enfield and becomes part of Hadley Wood. These carry a glazed rear extension (£60,000 to £120,000) or a kitchen wing handsomely when the detailing respects the original, and gardens are deep enough that the street never knows.
The common edge. Along Hadley Common and Bakers Hill, plots back onto the common with the green belt beyond. Additions here are designed for the long view as well as the boundary: quiet rooflines, dark frames, planting that stitches the garden back to the landscape.
The later houses. Monken Hadley has its share of twentieth-century infill, and these are the village's most flexible plots: double-storey reworks (£100,000 to £215,000) and whole-house programmes that lift the newer stock to the standard of the setting.
Every street is different. That's the point.
We design to Monken Hadley's stock and to what the council demonstrably approves — not to a template. A free site visit tells you what your house can take.
Get my free estimateHonest numbers
What an extension costs in Monken Hadley in 2026
Conservation work carries a real premium: handmade brick, true-bar joinery, lead and clay detailing and the extra design time all show up in the build cost, and they are precisely why consents succeed. Realistic all-in ranges, excluding VAT, professional fees and kitchen fit-out:
| Project type | Typical Monken Hadley cost | On-site time | Usual route |
|---|---|---|---|
| Single-storey rear | £60,000 to £120,000 | 3 to 4 months | Full application in the conservation area |
| Kitchen extension (incl. mid-range kitchen) | £75,000 to £140,000 | 3 to 4 months | Full application |
| Double-storey rework (later stock) | £100,000 to £215,000 | 5 to 7 months | Full application |
| Sensitive roof alterations | Priced on design | 6 to 12 weeks | Full application, listed consent where relevant |
| Garden building | £35,000 to £75,000 | 6 to 10 weeks | Route depends on siting |
| Basement leisure floor | Priced on design | 6 to 12 months | Full application |
Budget £3,500 to £5,500 per square metre at this specification, and see the luxury extension cost guide for how the larger bands break down. The quote itself works the way it does everywhere we build: fixed, itemised, VAT stated, and the signed figure is the paid figure.
Permissions, handled
Planning in Monken Hadley: what changes in a conservation area
Permitted development shrinks here. The basic 3m and 4m rear allowances survive in conservation areas, but the larger-home 6m and 8m prior-approval route does not apply, side extensions lose their PD rights, and roof enlargements need consent. The shortcuts are narrower, so the design case matters more.
Article 4 takes some houses further. Barnet has made Article 4 directions on the Monken Hadley conservation area. The 1972 direction covers mapped parts of it and removes the right to enlarge the house without an application, along with porches, outbuildings, hard standings, gates and walls, and exterior painting, so on those houses even the basic rear allowance has gone. A 2007 direction adds control over alterations facing a road, waterway or open space, which matters in a village set around a green and a common. We check which direction, if any, covers your house before anything is drawn.
Listed buildings add a consent. Many village houses are listed, which brings listed building consent alongside the planning application, covering internal as well as external works. We prepare both together, with the heritage argument written into the drawings.
The green belt sits behind the village, and in it. Houses on Hadley Green Road and around the common lie within the green belt as well as the conservation area, and plots running to the common's edge engage green belt policy; where they do, the original-building proportion test from our green belt guide joins the conservation case.
Timelines hold. A householder application still takes roughly eight weeks at Barnet; listed consent runs in parallel. How Barnet's heritage controls compare with Enfield's and Haringey's is set out in our North London extensions guide. The projects that stall are those designed without the heritage case, then redesigned under officer pressure. We front-load that work instead.
How it works
How it works
- Free design visit. We establish exactly which designations touch your house, conservation area, listing, green belt, and talk plainly about scope and budget.
- Design and drawings. A scheme composed to enhance rather than argue with the village, detailed to heritage standard.
- Consents, handled. Planning and, where relevant, listed building consent prepared and managed together through Barnet to decision.
- Fixed-price build. Craftsmanship matching the consent drawings, building control closed out, an immaculate handover.
Questions, answered
Monken Hadley extension FAQs
Can I extend a house in the Monken Hadley conservation area?
Yes. Conservation status raises the design bar rather than banning work: additions that defer to the original house, in honest matched materials, gain consent. We build the heritage case into the application from the start.
Is my house listed, and what does that mean for the project?
Many houses around Hadley Green and the church are listed, which adds listed building consent to the planning application and extends control to internal works. We check your exact designation at the first visit and manage both consents together.
What does an extension cost in Monken Hadley?
Plan on £3,500 to £5,500 per square metre at conservation specification in 2026. Single-storey rears typically run £60,000 to £120,000 and double-storey reworks on the later stock £100,000 to £215,000, excluding VAT and fees, with the bigger programmes banded in our luxury cost guide. Quotes are fixed and itemised.
Do permitted development rights apply in the village?
Only partially. The standard 3m and 4m rear allowances remain, but the larger-home 8m route, side extensions and roof enlargements all lose their PD status in a conservation area. Where Barnet's 1972 Article 4 direction applies, the right to extend without an application has gone altogether, and listed houses need listed building consent for most works anyway. We confirm your position before design.
Can I build a basement behind a period house?
Where the engineering and drainage allow, yes, and it is often the most conservation-friendly way to add serious space because the house shows nothing to the street. Full application, careful party wall management, priced on design.
How long will it take?
Design and heritage preparation take a few weeks, Barnet's decision around eight, listed consent in parallel where needed, then three to seven months on site depending on scale. Honest programme dates come with the quote.
What we build in Monken Hadley
The same team designs, gets planning and builds — one fixed, itemised price whichever route your Monken Hadley project takes.
- Kitchen extensions in Monken Hadley
- Side return extensions in Monken Hadley
- Double-storey & wrap-around in Monken Hadley
- Loft conversions in Monken Hadley
- Orangeries in Monken Hadley
- Garden rooms & offices in Monken Hadley
Checking the rules for Monken Hadley first?
Nearby areas we cover
What clients say
Rated 5.0 on Google
“The Extension Company built a 5m single storey rear extension on our Victorian terrace in Crouch End. Went down the permitted development route so no planning application needed, which they explained up front and saved us months. Kitchen-diner now opens onto the garden with sliding doors. £87k all in, matched the quote.”
“From the initial site visit onwards to my property in Barnet, we felt that the team actually listened to what we wanted. They suggested a few changes to the layout that we hadn't considered, and those changes have made a huge difference. Would definitely use again and recommend”
“Used The Extension Company for a loft conversion on our semi detached in Barnet and couldn't be happier. They explained what was possible at the first visit, sorted the planning side, and gave a fixed price with no surprises at the end. The hip-to-gable and rear dormer gave us a big double bedroom with an en-suite. Tidy, professional and finished on schedule. Would recommend to anyone in North London thinking about a loft conversion.”
“We had been putting off our loft conversion for years because the whole process felt overwhelming. The team made it much easier than expected and handled the drawings, planning and build for us. We now have a lovely extra bedroom and shower room.”
“Our wrap-around extension has completely transformed the ground floor. We now have the open plan kitchen and family space we wanted without losing all of the garden. Thanks to everyone involved.”
“Really pleased with the work from The Extension Company. We had our extension done in Hampstead and the whole experience was excellent. Great communication from start to finish, The quality of the finish is excellent and we’re really happy with the result. Would definitely recommend them if you’re thinking about an extension.”
Reviews shown word for word from our Google profile. See 9 more client reviews · Read all 16 reviews on Google
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