Building Terms Glossary

Also: habitable space

A planning and building regulations term defining rooms used for living, sleeping, eating, or working. The 45-degree rule and overshadowing assessment apply only to habitable room windows.

Also: junior hacksaw, mini hacksaw

A fine-toothed hand saw for cutting metal pipes, threaded rod, brackets, and plastic conduit. Available in full-size (300mm blade) and junior (150mm blade) versions. Essential for plumbing modifications and cutting fixings to length on site.

Also: bench plane, block plane, smoothing plane, jack plane

The non-powered predecessor to the electric planer, used for fine finish work and small adjustments where an electric planer would be excessive. Block planes are used by carpenters for trimming end grain and fitting doors. Slower than an electric planer but gives more tactile feedback and is preferred for very small final-pass adjustments.

Also: panel saw, hardpoint saw, crosscut saw, tenon saw

A non-powered saw for cutting timber, sheet materials, and plastic pipe by hand. Hardpoint panel saws (500-550mm) handle most site cutting. Tenon saws (250-350mm) give finer control for joinery. Indispensable when power isn't available or for quick one-off cuts.

Non-powered tools for measuring, marking, cutting, shaping, and finishing. Many of these are essential from day one of any construction project.

Also: HAVS, vibration white finger, VWF, hand-arm vibration

A permanent, irreversible industrial disease caused by prolonged use of vibrating tools including angle grinders, SDS breakers, and plate compactors. Causes numbness, tingling, pain, and loss of grip in the hands and fingers. HSE identifies concrete breakers and angle grinders as particularly high-risk tools. Governed by the Control of Vibration at Work Regulations 2005 which sets EAV of 2.5 m/s² A(8) and ELV of 5.0 m/s² A(8).

Also: safety helmet

A protective helmet that shields the head from falling objects, low beams, and impacts. Required on any site where there is overhead work, scaffolding, or structural alterations. Must meet EN 397 standard. Replace after any significant impact.

Also: MOT Type 1, crushed concrete, sub-base hardcore, granular fill

Compacted granular fill layer placed inside foundation walls to build up to slab level. A standard groundwork material appearing on every foundation quote.

Also: HBD, hbdsystems.co.uk

Specialist supplier of bespoke large-format fixed aluminium rooflights.

Also: head lap, tile overlap

Also: appeal hearing

An intermediate planning appeal procedure where the inspector leads a structured discussion with both parties.

Also: heat loss calculation, boiler sizing calculation, heating load calculation, heat loss survey

A calculation of the total heat demand on the heating system after an extension is added — fabric heat loss, ventilation heat loss, and hot water demand per room. Required before assuming an existing boiler can handle the increased load.

A handheld tool that blows hot air for stripping paint, softening adhesives, bending plastic pipes, and shrinking heat-shrink tubing. Useful for removing old paint from window frames and doors before repainting.

Also: heat shrink, heat shrink sleeve, electrical heat shrink, heatshrink

Plastic tubing that shrinks to a tight fit when heated with a heat gun, used in electrical work to insulate, protect, and waterproof wire joins, terminals, and connections. Common heat gun application at 120–180°C. Available in multiple diameters and shrink ratios. Using a lighter or match risks burning the tubing — the heat gun gives controlled, even heat.

Installs and commissions central heating systems, radiators, and underfloor heating

Also: heating supplies, boiler and radiator materials, wet heating system components

The gas appliances and heat emitters that deliver warmth to an extension, condensing boilers, radiators, and related controls. Gas work is Gas Safe only; homeowners must understand the sizing, siting and commissioning requirements that drive cost and compliance.

Also: tarpaulin, tarp, builders polythene sheet, frost protection sheet, masonry protection sheet

Waterproof sheet used to protect newly laid masonry from rain and frost. NHBC Standards 6.1.20 requires two layers when work stops: a thermal layer (hessian sacking) and a waterproof layer (plastic sheet or tarpaulin).

Also: ha

A unit of area equal to 10,000 square metres (roughly 2.47 acres). Used on OS maps to describe the coverage area of a map extract — for example, an A4 sheet at 1:1250 scale covers approximately 2 hectares.

Also: plumber's hemp, hemp yarn, hemp cord, hemp with Boss White

The traditional thread sealing method combining natural hemp fibre wrapped on threads and sealed with jointing compound. Still preferred by experienced plumbers for threads larger than 3/4 inch BSP and for galvanised pipe over 2 inches, where PTFE tape does not reliably seal loose or large threads.

Also: noggin strutting, solid strutting, blocking

Cross-bracing between floor joists and roof members that prevents lateral rotation and increases stiffness. Required at joist mid-span for spans over 2.5m and checked by the BCO at the structural stage.

Also: HETAS registered installer, solid fuel competent person scheme

UK government-authorised competent person scheme for solid fuel heating appliances including wood burners, multi-fuel stoves, and biomass boilers. HETAS-registered installers can self-certify their work under the building regulations. Homeowners should contact HETAS if their installer refuses to provide a certificate.

Also: high visibility vest, hi-vis waistcoat, tabard

A high-visibility fluorescent vest for being seen on site, especially when vehicles or plant machinery are operating. Required if deliveries are arriving by lorry or if work is near a road. Very cheap — buy a few.

Also: s139 Highways Act

Makes it a criminal offence to deposit a skip on a public road or highway without a permit from the local authority

Also: s169 Highways Act, s.169 HA 1980

Requires a highway authority licence before any scaffolding can be erected over or on a public highway. Distinct from s.139 which covers skips. Non-compliance carries an unlimited fine. Local authority fees range from £80-£300 application plus weekly maintenance charges.

Also: butt hinge template, hinge recessing jig, Trend hinge jig, concealed hinge jig, hinge sinker jig

A metal template used with a router to cut precise hinge recesses in doors and frames. The Trend Butt Hinge Template (75/100mm, ~£60) and Trend Concealed Cabinet Hinge Jig (35mm, ~£36) are the primary UK options. Requires a specific guide bush size (Trend Butt requires 16mm). Inner corners left by the router bit must be squared with a wood chisel before the hinge seats flat.

Also: hip tray, hip eaves tray, dry hip tray, hip undercloak tray

Also: arris hip tiles, bonnet hip tiles, hip caps, hip capping

Also: HMCTS, gov.uk/make-court-claim-for-money, Money Claim Online service

The government agency responsible for administering courts and tribunals in England and Wales, including the online Money Claim Online (MCOL) portal for filing civil claims without a solicitor.

A set of circular saw blades that fit into a drill for cutting large-diameter holes in wood, plasterboard, and thin metal. Used for installing downlights, running pipes through joists, and fitting door hardware. Sizes typically range from 19mm to 76mm.

Also: hollow door, hollow slab door, hollow panel door, honeycomb core door

An internal door with a cardboard honeycomb or hollow internal structure rather than solid timber. Has a maximum total material removal limit of 25mm before the internal structure is exposed — which cannot be patched and makes the door structurally unsound. Homeowners planning to trim doors for new flooring or underfloor heating clearance must identify whether the door is hollow or solid before planing.

Also: HOA, hoa.org.uk

Consumer organisation providing free and paid advice to UK homeowners on planning, extensions, party walls, and finding tradespeople

Also: houseofworktops.co.uk

Online worktop supplier identified in MSE forum threads as generally cheaper than Worktop Express for equivalent products. Direct-buy option for homeowners sourcing worktops independently.

Also: HWRC, tip, council tip, civic amenity site

Local authority household waste recycling centres run by county or unitary councils, accepting bulky and hazardous household waste including aerosol cans (with residue), small batteries, paint, and electrical items that cannot be put in kerbside recycling. Trade waste is generally not accepted. Free for residents within the council area; permits or proof of address may be required.

Also: householder planning application

The specific planning application type for alterations and extensions to a single dwelling. Fee is £528 from 1 April 2025 in England.

Also: HGCRA 1996, Construction Act 1996, Housing Grants Act

Gives you the right to stage payments and a proper payment process on construction contracts, and the right to adjudication if disputes arise.

HSE Guidance Note GS38 on electrical test equipment for low voltage systems. Prohibits NCV pens for proving dead and specifies test lead safety requirements.

Also: Safety in the use of abrasive wheels, HSG17 abrasive wheels

The HSE's definitive UK guidance document on abrasive wheel safety, directly governing angle grinder use on UK construction sites. Covers wheel mounting, guard requirements, speed matching, and PPE. NHBC Standards require site operatives to follow HSG17. PUWER 1998 replaced the Abrasive Wheels Regulations 1970 and HSG17 is the primary reference for legal compliance.

Also: planer knife, planer blade HSS, high speed steel planer blade, reversible planer blade

High Speed Steel planer blades — consumable accessories for electric planers. Widely available at UK retailers (e.g. DeWalt HSS 82mm 2-pack ~£8.99). Suitable for softwood and occasional use. Can be resharpened but this requires specialist equipment — most homeowners simply replace them. Cheaper than TCT blades but dull faster, particularly on hardwood or abrasive materials.

Also: lime, builders lime, bag lime

Added to mortar mixes to improve workability and flexibility. A small amount of lime in the mix makes mortar easier to lay and more forgiving of slight movement in the structure.

Also: calibrated hygrometer, relative humidity meter, RH meter, Protimeter, Tramex CMExpert

BS-mandated moisture testing tool for measuring screed relative humidity before flooring is laid. The hygrometer box method is the only BS-compliant approach.