Materials Guide
Practical guidance on building materials for your UK extension: what to buy, how much you need, and what to check when it arrives on site.
Aggregates
Hardcore, pea gravel, coarse aggregate, all-in ballast, and blinding concrete are the bulk groundwork materials that arrive on tipper lorries and form the base layer under every foundation, slab, and drainage run.
Concrete Products
Ready-mix concrete grades, rebar and mesh reinforcement, formwork, spacers, and damp-proof membrane for extension foundations and slabs.
Drainage
Inspection chambers, soakaway crates, geotextile membrane, underground drainage fittings, and channel drains are the below-ground products that move foul water to the sewer and surface water to a soakaway, and which building control inspects every joint of.
Ducting
Rigid and flexible ducting, external cowls, and insulation wrap for cooker hood extraction. Why 150mm rigid duct is the standard, and how the wrong substitution silently kills extractor performance.
Electrical Materials
Cable, back boxes, consumer units, MCBs, RCBOs, and wiring accessories for a domestic extension, including what each component does and what to check when your electrician specifies it.
External Works
Paving, turf, topsoil, and fencing materials for the outside reinstatement work that follows an extension, covering the jobs that finish the build visually and which builders' quotes often omit.
Finishing Materials
Plasters, fillers, sealants, adhesives, primers, and paint for the final stages of your extension, covering the materials that turn a shell into a room.
Fixings
Screws, bolts, anchors, brackets, and connectors for securing structural and non-structural elements in your extension build.
Flooring Materials
Porcelain and ceramic tiles, luxury vinyl tile (LVT), engineered wood, laminate, plus the adhesives, levelling systems and transition strips that hold it all together. The final finish that gets walked on every day.
Glazing
Roof windows and rooflights for a UK extension, from stock Velux-style pivot windows to bespoke large-format fixed aluminium rooflights, including lead times, fire-resistance rules, and who installs what.
Heating Materials
Condensing boilers, radiators and the wet heating system components that keep an extension warm. What you specify drives Part L compliance, Gas Safe notification, and your running costs for the next fifteen years.
Insulation
PIR boards, mineral wool, cavity batts, EPS, and insulated plasterboard for achieving building regs U-values in walls, floors, and roofs of a domestic extension.
Kitchen Units
Kitchen unit carcasses and the specialist fixings that hold a run together: carcass construction, cabinet connectors, worktop bolts, and cornice and pelmet trim.
Masonry
Blocks, bricks, sand, cement, lime, and mortar for the walls and below-DPC groundwork of a domestic extension, covering the raw materials your bricklayer will use every day.
Plumbing Materials
Copper pipe, pushfit fittings, soil pipe, waste traps, and stop valves are the materials your plumber will use, along with what to check on delivery and at building control inspections.
Roofing Materials
Tiles, membranes, lead flashing, EPDM, GRP, and battens are the materials that make your extension weathertight and what building control will inspect before they sign it off.
Screeding Materials
Liquid anhydrite and sand-and-cement screed are the level layers poured over UFH pipes before the final floor goes down. Get the product, depth, and drying time right or the flooring above it will fail.
Sheet Materials
Plasterboard, cement board, and lining products for walls, ceilings, and wet areas in your extension, including which board goes where and why it matters.
Site Protection
Heavy-duty tarpaulins and other sacrificial coverings used to keep an open extension shell weathertight and to protect finished joinery and floors during the messy second-fix trades.
Structural Steel
Universal beams, columns, and angle sections for UK domestic extensions: how steel is specified, fabricated, installed, and protected from fire.
Timber
Structural timber, treated wood, sheet boards, skirting, and architrave for framing, flooring, and finishing trim in your extension.
Tool Consumables
Consumable accessories for power tools used on an extension, including fuel cells for gas-powered nailers and HSS vs TCT replacement planer blades, when to specify them, and how often they need replacing.
Worktops
Quartz, granite, sintered stone, solid surface, solid wood, and laminate kitchen worktops: how each option performs, what they cost per linear metre, and why stone and solid-surface tops need templating once units are fitted.