Client: Lisa Murphy
Site Address: 37 Cromar Road, Thornton Heath, CR7 8BJ
Prepared By: David Hall, MK Build LTD
Quote Date: 17 June 2025
Quote Valid For: 30 days
Dear Mrs Murphy,
Thank you for considering MK Builders Services Ltd for your rear extension project. We pride ourselves on delivering high-spec residential construction with attention to detail and client care at the heart of everything we do.This proposal has been tailored to meet the brief discussed and includes a full breakdown of works, timelines, and associated costs to ensure transparency and clarity from the outset. We look forward to the opportunity to bring your vision to life.
7m x 4m Rear-facing Single-storey Extension
This quotation covers the full build and finish of a 7m x 4m rear-facing single-storey extension to your property. The project includes groundwork, structure, roofing, insulation, windows/doors, first- and second-fix plumbing/electrics, plastering, internal decoration, and basic kitchen installation.
We aim to deliver a robust, high-quality finish that meets current building regulations, energy standards and your expectations.
Completion Timeframe:
6–8 weeks (weather dependant)
Payment Terms:
25% upfront, balance settled in 3 stage payments
Total: £108,908.12
(Inclusive of VAT). Labour and basic materials included. Fixtures/fittings to be supplied by client.
Summary of works
Phase 1: Groundwork & foundations
We’ll begin by clearing the site and excavating for the trench foundations. Once the trenches are prepared, we’ll pour the concrete and set up the oversite with a damp-proof membrane to ensure a solid, protected base for your extension.
Includes:
- Site clearance
- Trench foundations
- Concrete pour
- Oversite prep
- DPM
Cost: £8,000
Timeframe: 9 days
Following the groundwork, we’ll construct the main shell of the extension using block and brickwork to match your property. During this phase, we’ll also install all necessary insulation and damp proofing, and construct the pitched tiled roof structure.
Includes:
- Brick/block external walls
- Damp proofing and insulation
- Roof frame and tiling
Cost: £12,500
Timeframe: 14 days
Phase 3: Windows, doors and rooflights
Next, we’ll fit your new bi-fold aluminium doors and install any UPVC windows and optional rooflights agreed upon in the plans. This installation will enhance natural light and open up the space beautifully.
Includes:
- Fit bi-fold doors
- UPVC windows
- Install any rooflights (if agreed)
Cost: £3000
Timeframe: 3.5 days
Phase 4: First Fix (Plumbing & Electrics)
In this stage, we’ll carry out the first-fix plumbing and electrical works. This includes running all the pipework for heating and water as well as wiring for lighting, sockets and appliances.
Includes:
- Plumbing for kitchen & heating
- Electrical wiring
Cost: £5,800
Timeframe: 7 days
Phase 5: Plastering & Internal Works
Once the services are in place, we’ll board and skim all the internal walls and ceilings to a high finish, followed by a mist coat to prepare for final decoration.
Includes:
- Full plaster skim
- Ceiling boards
- Mist coat
Cost: £3,200
Timeframe: 7 days
Phase 6: Second Fix & Kitchen Installation
This stage includes the second fix of electrics (fitting lights, sockets and switches) and plumbing (taps, radiators, waste), followed by the installation of a mid-range kitchen as specified.
Includes:
- Electrics (sockets, switches, lights)
- Plumbing fixtures
- Kitchen fitted
Cost: £8000
Timeframe: 7 days
Phase 7: Final Decoration & Finishes
Lastly, we’ll complete all decoration, including painting walls and ceilings, and lay down the final flooring (vinyl or laminate as chosen). We’ll also carry out a thorough clean and complete any snagging to ensure the finish meets your expectations.
Includes:
- Painting walls and ceiling
- Laminate/vinyl flooring
- Final clean and snag list
Cost: £4500
Timeframe: 7 days
Services & Materials:
Concrete Foundations
We will excavate and pour concrete strip foundations to support the extension. This includes trench work, formwork, and reinforced concrete.
Quantity: Covers a 7m x 4m footprint
Total: £4,000
Brick and Block External Walls
External walls will be constructed using traditional brick and block cavity walls, including insulation.
Quantity: Approx. 60m² at £90 per m²
Total: £5,400
Roof Structure and Tiling
A pitched roof will be installed with timber framing and finished in concrete tiles to match the existing house.
Quantity: Approx. 28m² at £160 per m²
Total: £4,480
Insulation (Floor, Wall, Roof)
High-quality thermal insulation will be installed throughout the extension to meet current building regulations.
Quantity: Full coverage (floor, wall, and roof)
Total: £2,300
Aluminium Bi-Fold Doors
Installation of stylish and secure aluminium bi-fold doors across the rear elevation.
Quantity: 3.5 metres wide, double-glazed
Total: £2,400
UPVC Window (Large)
Fitting of one large UPVC window with energy-efficient glazing.
Quantity: 1 window
Total: £550
Electrical Installation
Supply and installation of all first and second fix electrical components including sockets, lighting, and fuse board updates if required.
Quantity: Full installation for one room
Total: £3,200
Plumbing and Heating Works
Includes hot/cold water feeds, waste system, and one radiator installed and connected to existing heating system.
Quantity: Full fit-out for one kitchen/living space
Total: £2,600
Kitchen Supply & Install
Provision and installation of a mid-range kitchen including units, worktops, sink, tap, and fitting.
Quantity: Complete kitchen package
Total: £5,000
Plastering (Walls & Ceilings)
All new internal walls and ceilings will be plastered smooth and ready for decoration.
Quantity: Approx. 90m² at £18 per m²
Total: £1,620
Painting & Decorating
Two coats of emulsion on walls and ceilings, and gloss finish to woodwork.
Quantity: Entire extension interior
Total: £1,500
Flooring Supply & Install
Fitting of laminate or vinyl flooring throughout the new extension.
Quantity: Approx. 28m² at £35 per m²
Total: £980
Skip Hire & Waste Removal
All debris, surplus materials, and packaging will be removed and disposed of responsibly.
Quantity: 2 x 8-yard skips
Total: £1,200
Labour Costs
All site labour for the full 6–8 week build including tradesmen, project management, and finishing works.
Quantity: 6–8 weeks of labour
Total: £26,000
Contingency Budget
An allowance to cover unforeseen or reactive works that may arise during construction.
Quantity: 5% of project total
Total: £3,770
Terms & Conditions:
Payment Schedule
To secure your booking, a 10% deposit (£7,200 excl. VAT) is required. A further 40% is due at the start of the structure phase, followed by 30% upon commencement of second fix works, and the remaining 20% upon completion and snagging sign-off.
Project Duration
The estimated timeframe for completion is 6 to 8 weeks, depending on weather conditions and the smooth progression of works.
Working Hours
Our team operates Monday to Friday, from 8am to 5pm. However, we aim to be flexible where needed to suit your schedule or project needs.
Quote Validity
This quote is valid for 30 days from the date of issue. After this period, pricing may be subject to adjustment due to material costs or availability.
Insurance
We carry comprehensive public liability insurance, with coverage up to £20 million, to give you complete peace of mind throughout the project. Pleae ask for more details.
Planning & Building Regulations
It is assumed that planning permission and building control arrangements are the client’s responsibility, unless agreed otherwise in writing before works commence.
Unforeseen Works
If we encounter any hidden issues—such as poor soil conditions, existing drainage problems, or the discovery of asbestos—we will notify you immediately. These will be discussed and quoted for separately, outside of the original scope.
Snagging
We take pride in finishing all works to a high standard. Any final snagging or minor fixes will be completed within 5 working days of practical completion.
