Area guide · CM13 & CM15
House Extensions in Hutton Mount & Shenfield (CM13 & CM15)
Planning an extension on Hutton Mount or in Shenfield? Hutton Mount is a private residential estate in the proper sense: substantial inter-war and later detached houses on wide plots, unadopted tree-lined roads without pavements, and its own covenants and residents' management sitting alongside Brentwood's planning powers. That double structure is the defining fact of building here, because a scheme needs two readings, one against council policy and one against the estate's rules, and a design that passes only one of them goes nowhere. Down the hill, Shenfield adds the Elizabeth line and the prime Essex commuter money that follows it. The work all this produces is exactly our brief: whole-house programmes delivered to the standard the estate expects.
Live planning data
What Brentwood is approving on the Mount
Applications here go to Brentwood Borough Council, and the familiar householder routes work when the design respects the estate's grain: generous gaps between houses, deep front gardens behind the tree line, and massing that keeps the wide-plot rhythm intact. What trips schemes up is rarely the council alone. The estate's covenants and residents' management run in parallel, and they take a view on matters planning officers never touch, from materials and boundary treatments to how a build is conducted on an unadopted road. We read both rulebooks before designing, so the scheme that reaches Brentwood is the same scheme the estate can live with.
The scale of the houses puts most projects squarely in premium territory, which is why the Mount features in our luxury extensions work. Green belt wraps the settlement edges and frames the outermost plots, a test we take apart in our green belt guide.
Local knowledge
The stock: wide plots and commuter streets
The inter-war houses of Hutton Mount. The estate's founding generation: broad-fronted detached homes with real garden on every side. The classic brief is a rear extension plus internal remodel that brings a 1930s plan up to the way families actually live now.
The later rebuilds. Scattered through the estate are post-war and recent replacement houses where the volume already exists. Here the work is reconfiguration: kitchen wings, garden-facing glazing and first-floor reworks inside the established footprint.
The unadopted roads. Tree-lined, pavement-free and privately maintained, they shape the build as much as the design does. Deliveries, skips and verge protection are agreed with the estate in advance, and we programme around those commitments rather than apologising afterwards.
Shenfield's commuter streets. Around the station the stock is tighter and the driver is the Elizabeth line: families paying serious money for the connection, then extending rather than moving. Side returns, kitchen extensions and loft conversions carry most of the demand.
Every street is different. That's the point.
We design to Hutton Mount & Shenfield's stock and to what the council demonstrably approves — not to a template. A free site visit tells you what your house can take.
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What an extension costs in Hutton Mount and Shenfield in 2026
Wide plots invite big schemes, and estate-grade specification sets the floor. All-in construction ranges, excluding VAT, professional fees and kitchen fit-out:
| Extension type | Typical Hutton Mount cost | On-site time | Usual planning route |
|---|---|---|---|
| Side-return extension | £50,000 to £90,000 | 2 to 3 months | Often PD, covenants checked first |
| Single-storey rear | £60,000 to £120,000 | 3 to 4 months | Often PD, covenants checked first |
| Kitchen extension (incl. mid-range kitchen) | £75,000 to £145,000 | 3 to 4 months | Often PD, covenants checked first |
| Hip-to-gable loft + rear dormer | £65,000 to £115,000 | 6 to 10 weeks | Usually permitted development |
| Wrap-around extension | £95,000 to £180,000 | 4 to 6 months | Full application |
| Double-storey rear | £100,000 to £215,000 | 5 to 7 months | Full application |
Work here prices at £3,200 to £5,000 per square metre, with the specification rather than the postcode doing most of the deciding. The the larger bands are set out in our luxury extension cost guide, and every quote is a fixed, itemised document produced after a free design visit.
Permissions, handled
Planning on a private estate: two consents, one design
The covenant reading. Before anything goes near the council we establish what the covenants and residents' management expect of your plot: materials, boundaries, siting and the practicalities of building from a private road.
The Brentwood reading. Householder applications are decided in about eight weeks, and we manage the file from submission through to the decision notice.
Permitted development. PD rights survive on much of the estate, but covenants operate independently of them, so a PD scheme still gets the estate conversation. We document the planning side with a Lawful Development Certificate in every case.
The green belt edges. Plots at the settlement boundary are measured against the original building, so we calculate that baseline before the first drawing.
Party walls. Wide plots keep most neighbours out of range, but where the Act is engaged and surveyors are appointed, allow £1,000 to £2,500 per affected neighbour.
How it works
How it works
- Free design visit. Covenants, designations and plot walked through together, with a straight view on scope and cost.
- Design and drawings. One scheme composed to satisfy both the estate and Brentwood's policies at the same time.
- Planning, handled. Application prepared, submitted and managed to decision, with the estate kept onside throughout.
- Fixed-price build. An itemised contract figure, an agreed programme and a site run to private-road standards.
Questions, answered
Hutton Mount & Shenfield extension FAQs
Do the estate covenants stop extensions?
No, they shape them. The covenants and residents' management have a say in materials, boundaries and how work is carried out, and schemes that respect the estate's character proceed. We build that reading into the design from the first sketch rather than negotiating it afterwards.
Which comes first, the estate or the council?
In practice both threads run together, but we settle the estate conversation early because it can change the design, and a Brentwood approval is little use for a scheme the covenants will not wear.
What will a project cost on the Mount?
Budget £3,200 to £5,000 per square metre in 2026. Single-storey rears typically land between £60,000 and £120,000 and double-storey schemes between £100,000 and £215,000, excluding VAT and fees, with the larger programmes banded in our luxury cost guide.
Can contractors work from the unadopted roads?
Yes, with care. Access, deliveries and verge protection are agreed with the estate before the build starts, and any making-good is priced into the quote rather than argued about at the end.
Does permitted development apply on a private estate?
Usually, on the planning side: PD is a creature of planning law and covenants sit outside it. A compliant rear extension can proceed under PD with a Lawful Development Certificate while still needing the estate's blessing on materials and conduct.
How long from first call to finished rooms?
A few weeks of design, about eight weeks in planning where an application is needed, then three to seven months on site depending on scale, with dates set out alongside the fixed quote.
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What clients say
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“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.…” read the full review
“Really impressed with the entire project. The side extension and conservatory have been finished to a very high standard and the team made the process straight forward and stress-free. It’s transformed the space and added so much value, would definitely recommend.”
“Brilliant experience with the extension company, transparent from the word go. Completed a double story extension for me and I couldn’t be more pleased. Thank you”
“I got the extension company to do a bathroom refurb for us a January they done a great job they managed to fit in a large shower as well as a bath”
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Free site visit
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Free site visit anywhere in Hutton Mount & Shenfield, honest feasibility advice and a fixed, itemised price — design, planning and build handled end to end by the Pine Grove team.
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