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.
How we work · London & Hertfordshire
How a design and build project runs with LCCL: from the first call to the completion certificate
By Anderson & the LCCL Construction Team
Finchley N3 · Design & build, LABC award winners 2024 and 2026
One team, one contract and one point of contact from the first sketch to handover — that is the whole idea. This page walks through what actually happens: the free call, the survey and drawings, the approvals nothing starts without, the build week by week with LABC inspections at each stage, and the handover with your certificate and guarantees. If you want to know what you are signing up for before you book a call, it is here.
Quick answer
Every project is priced from a measured survey: a detailed itemised estimate — design, planning, structure, construction and warranty line by line. Guide ranges start from the instant estimator.
We check your address on day one and run the planning, building-regulations and party wall approvals in parallel — nothing starts on site until all three are signed off.
Typically 8–16 weeks of design and approvals, then 4–24 weeks on site depending on the project, with a weekly update from your project manager.
A free 30-minute phone call with our team, no obligation.
Design stage
8–16 weeks
On site
4–24 weeks by project
Your contact
One project manager
Awards
LABC 2024 & 2026 winners
LABC Building Excellence Award 2024
Best Residential Extension in London — Bohun Grove, East Barnet EN4: rear extension, hip-to-gable loft conversion and whole-house renovation
LABC Building Excellence Awards 2026
London Regional Winner, Best Conversion or Alteration — Weech Road, Hampstead NW6: penthouse loft conversion and full renovation
One contract
Architecture, structural engineering, planning, construction and project management — all under one contract
Guaranteed & insured
12-month workmanship guarantee; 10-year LABC structural warranty
What one contract includes
Design and build inclusive — from the first sketch to the completion certificate.
Measured survey of the house and garden
Architectural design and drawings, with revisions until you're happy
Planning application or Lawful Development Certificate, prepared and submitted for you
Building regulations drawings and structural calculations by our chartered engineer
Party wall notices served on your behalf (£300 each, at cost)
Foundations, drainage and any build-over agreement with Thames Water
Structure, roof, rooflights, doors and windows to a weather-tight shell
Plaster finish, first-fix electrics and plumbing, underfloor heating where specified
Fitting of the kitchen, flooring and second-fix items you supply
LABC inspections and completion certificate
A dedicated project manager and a weekly progress update
12-month workmanship guarantee; 10-year LABC structural warranty
How long each stage takes
Typical programme by project type — design and approvals first, then the build. Every project is scheduled individually after the survey.
Project
Design & approvals
On site
What we do that changes the outcome
Why it matters
When
Design done by the people who build
The drawings are buildable and priced; no gap between architect and builder
Weeks 1–4
Full-plans building regulations, never a building notice
The inspector checks a design already approved; no surprises at first fix
With planning
Party wall notices at design stage
The 2-month notice runs while the application is in, not after
With planning
Steelwork priced on every proposal
Typically £4,800 – £19,200 inc. VAT (£4,000 – £16,000 + VAT) on a Victorian terrace — in from day one
Estimate
One project manager, weekly update
You know what happened this week and what happens next
Throughout
What the price includes: survey, architectural drawings, planning or lawful development certificate, building-regulations drawings, structural calculations, construction to plaster finish with first-fix electrics and plumbing, LABC sign-off and guarantees. On top: kitchen units, worktops and appliances, flooring and second-fix items you choose. The figure on your itemised estimate is the figure you pay — nothing is added afterwards. Postcode dependent — the instant estimator adjusts the range for your area in thirty seconds, and a detailed itemised estimate follows one survey.
Payment: a booking fee on signing reserves your start window. The build is then paid in stages set out in the Schedule of Works — each stage is invoiced when the previous one is complete and paid before that stage starts, by bank transfer. The stage sums are fixed in the signed schedule, so you know every figure before we begin. Inner and Central London (Camden, Islington, Hackney, Wandsworth, Hammersmith, Westminster, Kensington & Chelsea, the City) cost more than outer London and Hertfordshire a little less — the instant estimate applies your postcode. These are estimated ranges — every home is surveyed and costed individually.
Who you deal with
Your project manager
One person from the first sketch to handover — the weekly update, the questions, the decisions. Not a different voice every week.
The design team
Our architects and chartered structural engineer draw and calculate what our site team will build — the drawings are buildable and priced, not a wish list.
The site team
Our construction team, with LABC inspections booked at every stage. Weech Road NW6 and Bohun Grove EN4 won LABC awards in 2026 and 2024.
Approvals
The three approvals nothing starts without
Planning, building regulations and the party wall run in parallel during the design stage.
Approval
What it is
Time
What we do
Planning or LDC
Permitted development confirmed by a Lawful Development Certificate, prior approval for 6 m / 8 m, or a full application
42 days – 8 weeks
Drawings, application and submission, all included
Building regulations
Full-plans drawings and structural calculations approved by LABC before we start
5–8 weeks
Engineer's calculations, submission, every inspection booked
Party wall
Notices to each adjoining owner; most consent; a surveyor only if one dissents
2 months' notice
Notices served for you (£300 each, at cost)
On site
What a build week looks like
Your project manager runs the programme and the trades, books LABC for each stage inspection (foundations, drains, steels, insulation, fire, completion) before anything is covered up, and sends you a weekly progress update — what was done, what happens next and any decision we need from you.
One point of contact throughout: the same person from the first sketch to handover, for you and for your neighbours.
See planning permission, building regulations and party wall notices for the detail.
Recent projects, start to finish
Bohun Grove, East Barnet EN4 — rear extension, hip-to-gable loft and whole-house renovation
LABC 2024 Best Residential Extension in London
Semi-detached family home One programme loft + extension + renovation
A total renovation of a family semi: a rear extension opening into a full-width kitchen and dining space with floor-to-ceiling glazing and skylights, a hip-to-gable loft conversion with a rear dormer, two Lusso Stone bathrooms, enlarged bedrooms, new windows throughout, a regulated outbuilding and landscaping.
Because the loft and extension ran under one contract, the steelwork for the open-plan ground floor and the loft floor was designed together and lifted in on the same day — one crane hire, one scaffold, one building-control file.
See the Bohun Grove project · All projects
%2C%20founder%20of%20LCCL%20Construction.jpeg)
ANDERSON · FOUNDER, LCCL CONSTRUCTION
Anderson's advice: book the design stage in summer, build in autumn
August is our slowest month for project starts — most families delay until the schools go back. That makes it the best time to get the survey, drawings and approvals done: you go through the council queue while everyone else is on holiday and start on site in September or October with the paperwork finished.
Approvals are the part of the programme you cannot compress. Design and planning typically take 8–16 weeks; leave them to the last minute and the build slips into the following year.
The five stages, in order
Every project follows the same sequence — only the weeks change.
WEEK 0
Free consultation call
A 30-minute phone call with our team about the house, what you want from the space and a realistic budget. Your instant estimate is the starting point.
WEEKS 1–4
Survey & design
Measured survey, architectural drawings and your detailed itemised estimate — design, planning, structure, construction and warranty priced line by line.
WEEKS 4–12
Approvals
Lawful Development Certificate or planning application, building-regulations drawings, structural calculations, party wall notices. Nothing starts on site until it is signed off.
BUILD
On site
4–24 weeks on site for most projects. Weekly updates from your project manager, one point of contact throughout.
HANDOVER
Sign-off
Snagging, LABC final inspection and completion certificate, guarantees in writing. 10-year LABC structural warranty.
“I highly recommend LCCL Construction. They completed our loft conversion to a very high standard, and the quality of their work throughout was excellent. The team was professional, reliable, and completed everything within a very reasonable timeframe. They…”
Alina A · Trustpilot
“Extension built by LCCL Construction. We have just recently completed our ground floor house extension on our semi-detached home in Finchley. The services we used were for the design and build of the extension which is three meters and the full breadth of…”
EVA HALL · Trustpilot
“We are very happy with the services from Lccl, Alex has done a great job on design and construction. We have used Lccl in the past for our rear house extension and have come back to instruct Lccl for our loft conversion too to our house in North London. As…”
Mia M · Google Reviews
Questions about how a project runs
A 30-minute phone call with our team about the house, what you want from the space and a realistic budget. If it makes sense, we book the measured survey; if it does not, we say so. No sales pitch.
Every line — survey, design, planning, structural calculations, building regulations, party wall, each stage of the build, finishes, warranty — priced from the measured survey. It is the figure you sign, not a guide range.
We do it: architectural drawings and structural calculations are in the price and are done by the people who will build from them. If you already have an architect's drawings we can price and build from those.
A booking fee on signing reserves your start window. The build is then paid in stages set out in the Schedule of Works: each stage is invoiced when the previous one is complete and paid, by bank transfer, before that stage starts. The stage sums are fixed in the signed schedule, so there are no surprises.
Often, for an extension or loft — much of the work is outside or above the existing rooms. A whole-house renovation or basement is different. We tell you at the survey what is realistic for your project.
Your project manager, the same person from the first sketch to handover, with a weekly update in writing. If it needs Anderson, you get Anderson.
A 12-month workmanship guarantee on every project, with a 10-year LABC structural warranty. Building control sign-off is through LABC — we are an LABC Registered Partner.
Typically 8–16 weeks of design and approvals, then 4–24 weeks on site depending on the project — a rear extension is on site 10–14 weeks, a loft 4–16, a two-storey extension 18–26, a new build 30–50.
Where we build
From Finchley N3 we cover North London, North-West London, Central London, South-West and West London, and Hertfordshire — and we also work across the rest of London, Buckinghamshire, Surrey, Kent and Essex. Recent extensions: East Barnet EN4, Finchley N3, Putney SW15, Mill Hill NW7, Wood Green N22 and Borehamwood WD6.