top of page
Loft conversions, house extensions, renovations, basements and new builds across London and Hertfordshire.
Services
Loft conversions, house extensions, renovations, basements and new builds across London and Hertfordshire.
Services
Loft conversions, house extensions, renovations, basements and new builds across London and Hertfordshire.
Services
Loft conversions, house extensions, renovations, basements and new builds across London and Hertfordshire.
Services
Call 020 8037 7332 or get an instant estimate online.
The 6-Metre Extension: How Many London Homeowners Use Prior Approval, Which Boroughs Refuse the Most, and Where the Neighbours Object — Nine Months of Government Data
Between October 2025 and June 2026 London's 33 boroughs decided 3,398 prior-approval applications for larger rear extensions — the 6-metre route on a terrace or semi, 8 metres detached. Two in three went through with no neighbour objection; 23 per cent were refused. But the borough matters: Enfield, Bexley and Hillingdon refuse under one in ten, Barnet 45 per cent, Lewisham one in two. Every borough and the ten Hertfordshire districts ranked, and when the 3-metre extension is
LCCL Construction
3 hours ago8 min read
Extend or Move? What a London Move Costs in 2026, Set Against a Loft or an Extension — With the Numbers
Moving from an average London terrace to an average London semi costs about £40,000 in stamp duty, agent, legal and moving fees before the £82,000 price step — money that is gone on completion day. A rear dormer loft starts from £56,400 inc. VAT, a rear extension from £42,000, and Nationwide puts the value added by a bedroom-and-bathroom loft or extension at up to 24 per cent. The arithmetic, every figure sourced and dated, and the cases where moving still wins.
LCCL Construction
2 days ago9 min read
Rear Extensions in Brockley SE4: Side Returns and Rear Extensions on the Victorian Terraces, the Conservation Area, Permitted Development and Prices
Brockley is one of the largest Victorian suburbs in south-east London: wide tree-lined roads of three-storey terraces and villas with rear additions, long gardens and side returns, most of it inside the Brockley conservation area. This guide covers which extension suits an SE4 house, where the conservation area changes the permitted development answer, what Lewisham's building control inspects, what each extension costs inc. VAT and the terrace projects of ours that show how
LCCL Construction
2 days ago7 min read
Basement Conversions in Kensington and Chelsea: What the Royal Borough Allows, What It Costs and How a Basement Gets Approved
Kensington and Chelsea has the strictest basement policy in London and, after the loft and the rear extension, the basement is usually the last space a house there has left. This guide covers the three kinds of basement — a cellar refit, a lowering and a new dig — what the Royal Borough's policy allows, what the planning application has to contain, what building control and the neighbours will ask for, and what each costs inc. VAT, with the St John's Wood basement we built as
LCCL Construction
2 days ago7 min read
House Extensions in Notting Hill W11: Rear and Side-Return Extensions on the Stucco Terraces, Conservation Areas, Article 4 and Prices
Notting Hill is almost entirely conservation area — Pembridge, Ladbroke, Norland, Kensington Park — and most of its houses are stucco terraces with a rear addition and a side return. A modest rear extension usually stays permitted development even here, the larger 6-metre route does not, side extensions need an application and several streets carry Article 4 directions. This guide covers which extension suits a W11 house, the planning route, building control and the prices in
LCCL Construction
2 days ago7 min read
Which London Councils Decide Your Extension Fastest? 24,000 Householder Applications, Ranked by Borough
Every householder planning application — an extension, a loft, a garden room — is supposed to be decided in eight weeks. We took the government's district data for the year to 30 June 2026, nearly 24,000 London decisions and 5,000 more in Hertfordshire, and ranked every council on how many it decided on time, how many of those needed an agreed extension of time to count, and how many it approved. The gap between the best and worst borough is wider than most homeowners expect.
LCCL Construction
5 days ago8 min read
Is Open Plan Over? What 134 London Homeowners Actually Priced in October
This week's property pages say open plan has had its day and homeowners want rooms with doors again. We checked what London homeowners actually asked for when they priced an extension on our estimator in October 2026: 134 estimates, 88 with an extension, and 40 of those — 45 per cent — chose to knock through into the existing house. The other half kept the wall. That is not the end of open plan; it is broken plan, and this is what it costs and when each answer is right.
LCCL Construction
6 days ago6 min read
Why Two London Extension Quotes Can Be £50,000 Apart: We Checked 40 Published Price Pages
On 2 November 2026 we read 40 published price pages for London loft conversions, extensions, garage conversions and basements — builders, design-and-build firms, architects and the national trade guides — and put every figure on the same basis. The spread for an identical job was up to £50,000. Only 9 of the 40 pages said whether VAT was included; only 2 said the price covered design, structural calculations and building control. This is what we found, why quotes differ, and
LCCL Construction
Nov 48 min read
House Extensions in Welwyn Garden City AL7 and AL8: Garden City Rules, the Estate Management Scheme, Permitted Development and Prices
Welwyn Garden City is two towns with two rulebooks. The original garden city — Handside, Sherrardspark, the roads off Parkway — sits inside a conservation area and the council's Estate Management Scheme, so even a permitted development extension needs consent to its appearance. The post-war neighbourhoods to the east follow the ordinary permitted development rules. This guide explains both, what each extension costs inc. VAT and what building control inspects.
LCCL Construction
Nov 48 min read
Prior Approval and Neighbour Objections: What Happens When the Neighbours Object to a 6 m or 8 m Extension
The larger home extension route lets a 6 m extension on a terrace or semi, or 8 m on a detached house, go ahead without a planning application — unless a neighbour objects. This guide explains exactly what happens when one does: the 21-day consultation, the single test the council is allowed to apply, what an objection can and cannot achieve, how long the decision takes, and the three ways forward if prior approval is refused — including the 3 m or 4 m extension that needs no
LCCL Construction
Oct 288 min read
House Extension Plans: The Four Sets of Drawings You Need, Who Draws Them, When and What They Cost
Every house extension in London runs on four sets of drawings, and most of the delays and surprises on a project come from one of them being missing, late or drawn by the wrong person. This guide explains what each set is for — planning or Lawful Development Certificate drawings, building regulations drawings, the structural engineer's calculations and the construction drawings — who produces it, in what order, what it costs, and what a quote priced from the wrong set leaves
LCCL Construction
Oct 288 min read
Semi-Detached House Extension Rules: What You Can Build at the Back, the Side and Upstairs Without Planning Permission
A semi-detached house has one free side and one shared wall, and the permitted development rules treat them differently. What you can build on a semi without a planning application: a 3 m rear extension as of right, 6 m by prior approval, a single-storey side extension up to half the width of the original house, and a two-storey rear extension where the garden is long enough — with the height and boundary limits, what the shared wall means for the party wall, and the from-pri
LCCL Construction
Oct 289 min read
Bungalow: Loft Conversion and Extension Under Permitted Development — Where the Roof Allows It, Fixed Price
A bungalow has the most generous footprint of any house and the least usable roof. Whether the loft can be converted without a planning application comes down to one measurement at the ridge; the extension rules are the same generous detached-house limits. Here is what the house can take, what each product costs at a fixed price, and when a raised roof puts you into planning.
LCCL Construction
Oct 236 min read
The 6 m and 8 m Rear Extension Without Planning Permission: Prior Approval Explained
Permitted development normally stops at 3 or 4 metres. The larger home extension rules take a single-storey rear extension to 6 metres on a terrace or semi and 8 metres on a detached house, through a 42-day prior approval notification instead of a planning application. Here is how the route works, what the council checks, and what the bigger room costs.
LCCL Construction
Oct 237 min read
Detached House: Loft Conversion and Extension Under Permitted Development — Larger Limits, Fixed Price
Detached houses get the most generous permitted development allowances of any home — a 4 metre rear extension, 8 metres with prior approval, and 50 cubic metres of roof that can be used on both sides. Here is what that means in rooms, what each product costs at a fixed price, and the two places a detached house still has to go to planning.
LCCL Construction
Oct 226 min read
Victorian Terrace: Side-Return Extension and Loft Conversion Under Permitted Development, Fixed Price
The Victorian terrace has the two most valuable gaps in London housing: a dark side return beside the kitchen and a loft over a butterfly or pitched roof. Both can usually be filled without a planning application, and both have a fixed price. Here is what the house can take, what it costs, and where the conservation-area line falls.
LCCL Construction
Oct 226 min read
1930s Semi-Detached House: Loft Conversion and Rear Extension Under Permitted Development, Fixed Price
The 1930s semi is the most common house in outer London and Hertfordshire, and the one permitted development was practically written for: a hipped roof that turns into a full loft, a rear wall that can come out three metres, and in most streets no planning application at all. Here is exactly what the house can take, what each product costs at a fixed price, and the two things that catch owners out.
LCCL Construction
Oct 226 min read
House Extensions in Putney SW15: Fixed-Price Side-Return and Rear Extensions from £42,000
Putney's Victorian and Edwardian terraces were built with a side return and a narrow back kitchen — exactly the layout a single-storey extension transforms, and in most streets it can be done under permitted development. Here is what a Putney extension costs at a fixed price, the Wandsworth planning points that matter, and how our design and build team runs the job under one contract.
LCCL Construction
Oct 196 min read
House Extensions in Hertfordshire: Fixed-Price Permitted Development Extensions from £42,000
From Borehamwood and Potters Bar up to St Albans, Watford, Harpenden and Hertford, Hertfordshire's semis and detached houses have the gardens and the permitted development rights that make a fixed-price extension possible without a planning application. This is our Hertfordshire hub: what you can build, what it costs, which council you deal with, and how one design and build contract covers all of it.
LCCL Construction
Oct 196 min read
House Extensions in Watford WD17–WD25: Fixed-Price Permitted Development Extensions from £42,000
Watford's 1930s semis and Victorian terraces are some of the easiest houses in Hertfordshire to extend without a planning application. Here is what permitted development allows on a Watford house, what a fixed-price rear, side or kitchen extension costs, and how our design and build team takes the job from the first phone call to the completion certificate.
LCCL Construction
Oct 196 min read
5.0
average rating is 5 out of 5
“We did a 3x10m single storey rear extension with LCCL recently. It was scheduled to take 12 weeks to complete but with Alex's experience and agile project management, we are ahead of schedule (finished in 10). Alex, and LCCL,is extremely knowledgeable and…”
Galichet Christophe · Google Reviews
5.0
average rating is 5 out of 5
“Hired LCCL Construction to design and build us a rear house extension. Found them easy to work with and are pleased with the results. They have been recommended to us for the whole build including designs and construction. The rear extension feels amazing,…”
James Grimsdale · Google Reviews
5.0
average rating is 5 out of 5
“I highly recommend LCCL Construction. From the start of discussing ideas and planning I can tell you they were very professional and efficient. I had my kitchen and loft done a year ago now and am absolutely thrilled! Exactly what I wanted!”
Nadya Christou · Google Reviews
%2C%20founder%20of%20LCCL%20Construction.jpeg)
Start with a figure, then a conversation.
Get an instant estimate for your postcode, or book a free 30-minute call with our team. Call us on 020 8037 7332, Monday to Saturday 08:00–18:00.
One team, one contract, one point of contact — from first sketch to handover.
bottom of page