Material Procurement in London Construction: How It Works and Who Pays

One of the questions clients most often ask when commissioning a London building project is: who buys the materials? The answer varies by project, contract type, and arrangement, but understanding the main models helps you make better commercial decisions.

The Main Procurement Models

Contractor-procured (all-in contract price): The contractor purchases all materials and includes the cost in the contract sum. The client pays one price and the contractor takes the risk on material costs.

Advantages: simplicity for the client; contractor takes on supply chain risk (price increases, delays); single point of responsibility.

Disadvantages: contractor's mark-up on materials is typically 15–30% above trade cost; client has less control over product selection; if specification changes, the contractor reprices the variation.

Client-supplied materials: The client purchases some or all materials directly, typically on trade accounts with suppliers or at retail, and delivers them to site. The contractor installs only.

Advantages: client retains product control; can buy at best market price; can use preferred suppliers.

Disadvantages: client takes on supply risk (materials must arrive on time, correct specification, correct quantity); risk of programme delay if materials are late or wrong; if contractor has to stop because materials have not arrived, client may face delay costs.

Hybrid (client-supplied finishes, contractor-supplied structure and services): The most common model in London residential refurbishment. The client supplies "second fix" finish items — tiles, sanitaryware, kitchen units, taps, light fittings, floor finishes — while the contractor supplies structural materials, plasterboard, insulation, pipework, cable, fixings, and first-fix items.

This is the default RCB position: all second-fix materials are client-supplied unless specifically agreed otherwise.

What "Second Fix" Means

First fix refers to everything that goes in before the plaster — structural work, pipe runs, cable routes, insulation. Second fix refers to everything that goes on top of the finished surfaces — sanitaryware, kitchen units, doors, skirting boards, floor coverings, light fittings, sockets, and all visible finishes.

The distinction matters because:

• Second fix items are visible — the client has a strong interest in choosing them personally
• Second fix items are variable in quality and cost — a basic kitchen can cost £5,000 and a bespoke kitchen £50,000+
• Including second fix in the contractor's price would require them to specify and price every individual item, which is impractical at estimate stage if the client has not yet chosen

The Risk in Client-Supplied Materials

When clients supply their own materials, the risk of getting it wrong moves to the client:

• Wrong quantity: Client orders 40m² of tiles for a bathroom that needs 45m² — the shortfall delays tiling and may not be available if the tile has sold out
• Wrong specification: Client orders porcelain tiles that are not suitable for floor use in a wet room
• Late delivery: Materials arrive two weeks after the trades are ready — trade teams redeploy to other work and the programme slips
• Damaged on delivery: Tiles arrive cracked; replacement takes weeks
• Wrong colour/model: Client ordered grey tiles but receives beige due to online description ambiguity

These risks are manageable with care, but they are real. The practical mitigations:

• Order with 10–15% overage on tiles and other cut materials
• Order well ahead — never assume online delivery timelines are reliable for a building project
• Confirm specifications carefully with the tile/sanitaryware supplier before ordering
• Arrange delivery in agreement with the contractor to coincide with when the trade needs the material

Contractor Mark-up on Materials

Contractors typically mark up materials by 15–30% above their trade purchase price. This is legitimate and covers:

• Credit risk and administration of supplier accounts
• Responsibility for correct specification and ordering
• Storage, handling, and wastage management
• Programme risk if materials are delayed

If a client wants to supply their own materials primarily to save on mark-up, it is worth calculating whether the saving justifies taking on the supply risk. For small quantities of standard items, the saving may be modest. For expensive client-chosen items (kitchen, sanitaryware), the saving can be significant.

The London Context

London has excellent trade materials supply infrastructure:

• Jewson, Travis Perkins, Buildbase and other national builders' merchants have multiple London branches
• Tile suppliers: Topps Tiles, Walls and Floors, Porcelain Superstore, Fired Earth, and many specialist importers for premium tiles
• Kitchens: Howdens (trade only), Symphony, Magnet, John Lewis, Wren, and many bespoke makers
• Sanitaryware: Bathstore, Bathrooms to Love, CP Hart (premium), and many others
• Lighting: TLC, Sparks, and many online retailers

Trade delivery in London is generally reliable but not always on precise timescales — morning or afternoon delivery windows are common at builders' merchants. Access to a London residential project (parking, unloading bay) is a recurring friction point — discuss with your contractor.

RCB Design & Build

RCB's standard position is that second-fix finish materials are client-supplied, allowing clients to control product selection while RCB supplies and manages structural, services, and first-fix materials. We advise on specifications, quantities, and timing to support smooth client procurement. Contact us to discuss your project.