How to Quote a Building Job: A Practical Guide for Builders

Quoting a building job means breaking down an entire project — groundworks, structural work, multiple trades, materials, plant hire, and subcontractors — into an itemised price the client can understand and accept. For builders, accurate quoting is the foundation of a profitable business.

Building work is where quoting gets serious. Unlike a single-trade job, a building project pulls in groundworkers, bricklayers, carpenters, roofers, plasterers, and a string of specialists — each with their own rates, timelines, and materials. Get the quote wrong and you don't just lose margin on one task; the losses compound across the entire project. The builders who stay profitable are the ones who have a disciplined system for pricing every element before they commit to a number.

This guide covers a practical, step-by-step approach to quoting building jobs accurately — from the first site visit through to handing the client a professional, itemised quote they can say yes to.

1 Start With a Proper Site Survey

Every accurate quote begins with understanding what you're actually building, and what you're working with. A building job quote based on a phone conversation or a set of drawings alone is a guess, not a price.

• Visit the site before you quote. Drawings tell you the design intent; the site tells you the reality. Ground conditions, access constraints, neighbouring structures, existing drainage runs, and the state of the property all affect cost.
• Understand the full scope. Is it a single-storey rear extension, a two-storey side return, a loft conversion, or a full renovation? Does the client want structural alterations, or is this cosmetic? Pin down exactly what's included before you start pricing.
• Check for complications. Party wall requirements, conservation area restrictions, trees with TPOs near the foundation line, asbestos in existing structures, Japanese knotweed — these are cost drivers that won't show up on a plan.
• Clarify what the client is providing. Are you pricing the full build including kitchen and bathroom fit-out, or just the shell? Is the client supplying any materials directly? Who's responsible for building control and planning fees?

Tip: Record a video walkthrough on site, narrating what you see as you go. Tools like VoxTrade let you capture a voice description of the full scope during the visit — covering room dimensions, existing conditions, access issues, and client preferences — so nothing gets forgotten when you sit down to price the job.

2 Break Down the Work by Trade

A building job isn't one task — it's a sequence of trades, each with distinct material and labour costs. The only way to quote it accurately is to break it down trade by trade and price each element individually.

Groundworks and Foundations

This includes site clearance, excavation, foundations (strip, trench fill, or piled depending on ground conditions), below-ground drainage, and concrete oversite or beam-and-block floors. For a typical single-storey extension, groundworks alone can run £8,000-£15,000 depending on ground conditions and foundation depth. Bad ground that needs piling can double that figure.

Structural and Brickwork

Blockwork, brickwork, steelwork, lintels, cavity insulation, DPC, and wall ties. A single-storey extension typically costs £1,800-£2,500 per square metre all-in for the shell — but that figure varies significantly by region and specification. A high-spec two-storey extension with facing brick can push past £3,000/sqm.

Carpentry and Roofing

Roof structure (cut or truss), felt and battens, tiles or slates, fascias and soffits, flat roof sections, and first fix carpentry including stud walls, floor joists, and door linings. A loft conversion — which is heavily carpentry and structural — typically falls in the £40,000-£65,000 range for a dormer, or £50,000-£80,000 for a mansard, depending on the property and specification.

Plastering and Dry Lining

Plasterboard, skim coat, external render if specified, and any decorative cornicing. For a standard extension, allow £40-£60 per square metre for board and skim. If the client wants Venetian plaster or specialist finishes, price those separately.

Second Fix and Finishes

Second fix carpentry (doors, skirting, architrave), decoration, flooring, kitchen fit-out, and bathroom installation. A kitchen refit typically runs £15,000-£30,000 depending on units and appliances, while a bathroom fit-out sits around £6,000-£12,000. These costs are on top of the structural build.

3 Get Materials and Plant Right

Material costs are the backbone of any building quote, and getting them wrong — even by 10% — can wipe out your profit on a large job.

• Price materials from your merchants at current rates. Don't rely on last year's prices. Timber, steel, and insulation have all seen significant price movements in recent years. Get written quotes from suppliers for anything over a few hundred pounds.
• Add a realistic waste factor. Bricks: allow 5-10% for cuts and breakages. Timber: 10-15%. Plasterboard: 10%. Tiles: 10-15% depending on the layout. These aren't luxuries — they're what the job actually uses.
• Don't forget plant hire. Excavators, telehandlers, scaffolding, skip hire, and temporary fencing are real costs. Scaffolding for a two-storey extension might run £1,500-£3,000 for the duration. Skip hire at £250-£400 per skip adds up fast on a demolition-heavy job.
• Include preliminaries. Site welfare (portaloo hire), temporary electrics, site insurance, and protective hoardings are costs the client rarely thinks about but you still have to pay for.

4 Labour: Day Rates vs Fixed Price and Managing Subcontractors

Most builders use a mix of their own labour and subcontractors. How you price each element depends on who's doing the work and how you structure the contract.

• Your own labour: know your day rate and apply it honestly. If you're running a team, calculate the fully loaded cost — wages, employer's NI, holiday pay, tools, van costs — and add your margin. A skilled tradesperson in 2026 typically costs £200-£280 per day fully loaded, before your markup.
• Subcontractors: get written quotes for each package. Don't guess what the electrician or plumber will charge. Get firm prices from your regular subcontractors and include them line by line. Add 10-15% to cover your management overhead and risk.
• Fixed price vs day rate. For most building quotes, the client wants a fixed price. That means your day-rate calculations need to be realistic about duration. If you think the brickwork will take three weeks with a two-man gang, price for three and a half. Weather days, delivery delays, and snag lists are inevitable.
• Sequence matters. Building work follows a critical path. If the groundworker overruns by a week, the bricklayer, roofer, and everyone after them gets pushed back. Build realistic programme float into your quote to avoid paying subcontractors to stand idle.

Tip: Keep a record of how long each trade phase actually takes on every job you complete. After a few projects, you'll have your own benchmarks rather than relying on industry averages — and your quotes will be far more accurate as a result.

5 Contingency, Overheads, and Presenting to the Client

Two things separate profitable builders from busy-but-broke builders: realistic contingency allowances and proper overhead recovery.

Contingency

• New build work: allow 5-10%. You're building from scratch on a clear site with approved plans. Surprises are fewer, but they still happen — bad weather weeks, supply chain delays, specification changes.
• Renovation and extension work: allow 10-15%. The moment you open up an existing structure, you're dealing with the unknown. Hidden rot in floor joists, undersized existing foundations, undocumented drainage runs, and electrical wiring that doesn't match the plans are all common.
• Period property or listed building: allow 15-20%. Conservation requirements, matching materials, and structural surprises in older buildings can escalate costs significantly.

Overheads and Margin

Your quote needs to cover more than materials and labour. Office costs, insurance, accountancy fees, vehicle costs, tool replacement, and your own salary are real overheads. A common approach is to add 15-20% on top of your direct costs to cover overheads, then a further 10-15% for profit. If your total markup feels uncomfortable, the answer is usually to find efficiencies in the work — not to cut your margin.

Presenting the Quote

• Itemise everything. Break the quote into sections — groundworks, superstructure, roof, first fix, second fix, external works — with subtotals for each. Clients trust transparent pricing and it gives you a clear structure for managing variations.
• State inclusions and exclusions clearly. Does the price include building control fees? Planning application costs? Demolition of the existing structure? Kitchen supply? Decorating? Spell it out. Ambiguity leads to disputes.
• Include a payment schedule tied to milestones. For example: 10% on commencement, 20% at DPC level, 20% at plate level, 20% at watertight, 20% at practical completion, 10% retention released after 12 months. This protects both parties.
• Set a validity period. Material prices move. A quote valid for 30 days gives the client time to decide without exposing you to six months of price inflation.

Using VoxTrade, you can build and send itemised quotes directly from your phone — including per-project cost tracking so you can see your actual margin as the job progresses, not just what you hoped it would be when you priced it.

Wrapping Up

Quoting a building job well is about discipline, not guesswork. Survey the site properly so you understand what you're pricing. Break the work down trade by trade so nothing gets missed. Price materials at current rates with a realistic waste factor. Be honest about labour duration and subcontractor costs. Add contingency that reflects the actual risk — and don't apologise for including proper overheads and profit.

The builders who consistently make money aren't the cheapest — they're the ones who price accurately, present professionally, and track their costs through to completion. Get your quoting system right and you'll win better jobs, avoid nasty surprises mid-build, and actually keep the margin you quoted for.

For more trade-specific quoting guides, browse the VoxTrade blog — or download the app and try voice quoting on your next site visit.