Building glossary

AACE 18R-97Standard · Cost estimate classification system

The accuracy range stated on each result, according to how well the project is defined. Used on

AluminiumSpecification choice · Doors and windows

Maintenance-free, the standard on modern builds. Used on

Aluminium sheetSpecification choice · Roof

Does not rust, which matters on the coast and under 2,000 mm of rain. Lighter than steel so less roof structure, but it dents and it walks. Used on

Architect-led turnkeySpecification choice · How the work is delivered

Design, supervision and warranties handled by a professional. Used on

Beam and blockSpecification choice · Upper floors

Less concrete and less formwork, shorter spans. Used on

Beam and block floorSpecification choice · Ground floor

Joists and infill blocks. Lighter than a solid slab. Used on

Beams and ring beamsMeasured work · Superstructure

Ring beam, lintels and beams, of the same section. Used on

BoreholeMeasured work · External works

A water borehole, by the metre drilled. Not the pump, the tank or the tower: those are priced separately. Used on

Borehole and tankSpecification choice · Water supply

Full independence. The most widespread solution outside the city centre. Used on

Boundary wallMeasured work · External works

A boundary wall or a light fence. Wind, not load, decides what it needs. Used on

Cast in situ terrazzoSpecification choice · Floor finish

Poured, ground and polished in place. Slow and labour-heavy, but it lasts decades and can be repaired, where a cracked tile stays cracked. Used on

CeilingMeasured work · Finishes

Panelling or board on timber battens. Not only a finish: it is what keeps dust, bats and roof heat out of the room. Used on

Ceiling fansSpecification choice · Ventilation and cooling

Cheap and very effective in this climate. Used on

CeilingsSpecification choice

Under a sheet roof, the ceiling is what makes the difference to thermal comfort. Used on

Cement render and paintSpecification choice · Wall finish

The standard, inside and out. Used on

Centralised air conditioningSpecification choice · Ventilation and cooling

Apartment blocks and commercial premises only. Used on

Ceramic tilesSpecification choice · Floor finish

The default choice, wide price range. Used on

Clay or concrete tilesSpecification choice · Roof

A stronger roof structure is mandatory: tiles weigh about five times what sheet does. Used on

ColumnsMeasured work · Superstructure

Reinforced concrete columns, all of the same section. Used on

Compacted earth and screedSpecification choice · Ground floor

Earth rammed in layers, then a 40 mm mortar screed. Half the rural building stock sits on this. No reinforced slab and therefore no steel: it is the cheapest ground floor there is. It absolutely requires a membrane under the screed, or damp rises and lifts everything laid on top of it. Used on

Compressed stabilised earth blockSpecification choice · Wall construction

Cheap and climate-appropriate, but weak in compression and water-sensitive: needs a roof overhang and a masonry plinth. Used on

Corrugated fibre-cement sheetSpecification choice · Roof

Far quieter under rain than steel and much cooler in sun, since it does not radiate heat into the room. Against that it is heavy and brittle: it needs a denser roof structure and nobody should walk on it. Check it is asbestos-free, because older or grey-import sheets still contain it. Used on

Design, drawings and permitsWork package

Architect, working drawings, soil survey and building permit. Used on

Direct lorry accessSpecification choice · Site access

Delivery at the work face. Used on

Doors and windowsMeasured work · Finishes

Doors and windows, counted and fitted. Louvres ventilate without opening, which matters in this climate. Used on

Double glazingSpecification choice · Glazing

Imported and expensive, only relevant in air-conditioned rooms. Used on

Earthworks and foundationsWork package

Clearing, excavation, footings, ground beam and ground-bearing slab. Used on

Electric water heaterSpecification choice · Hot water

Simple but power-hungry. Used on

Electrical installationMeasured work · Finishes

Sockets, lighting points and the board. Where the power comes from is chosen in the budget estimate. Used on

EN 12056-3Standard · Gravity drainage systems inside buildings, part 3: roof drainage

Sizing gutters and downpipes from the roof area and the rainfall intensity. Used on

EN 13707Standard · Reinforced bitumen sheets for roof waterproofing

Two-layer SBS waterproofing on a flat slab, with 150 mm upstands. Used on

EN 13967Standard · Plastic and rubber damp proof sheets, including basement tanking

Polythene sheet under the ground slab against rising damp from the soil. Used on

EN 13969Standard · Bitumen damp proof sheets, including basement tanking

Bituminous membrane under a raft, in a high water table or a basement. Used on

EN 14891Standard · Liquid applied water impermeable products for use beneath tiling

Tanking slurry in wet rooms, applied before tiling. Used on

EN 14967Standard · Bitumen damp proof courses

Damp proof course bedded into the wall 150 mm above finished ground. Used on

EN 1504-2Standard · Surface protection systems for concrete

Liquid applied waterproof coating on a flat roof. Used on

EN 1990Standard · Basis of structural design

Load combinations and partial factors: 1.35 on permanent actions, 1.5 on variable ones. Used on

EN 1991-1-1Standard · Actions on structures: densities, self-weight and imposed loads

Material densities and imposed loads by occupancy category, which is what makes the sizing follow the building’s use. Used on

EN 1992-1-1Standard · Design of concrete structures

Slabs, beams, columns and footings: span/depth ratios, flexure with the 0.167 balanced limit, shear per §6.2.2, bar spacing per §8.2, minimum steel per §9.2.1.1 and §9.3.1.1. Used on

EN 1993-1-1Standard · Design of steel structures

Steel beams and columns: plastic moment resistance §6.2.5, flexural buckling §6.3.1 on curve b, and deflection capped at L/250. Used on

EN 1995-1-1Standard · Design of timber structures

Floor joists: f_m,d = k_mod · f_m,k / γ_M with k_mod 0.8 in service class 2, and deflection capped at L/300. Used on

EN 1996-1-1Standard · Design of masonry structures

Characteristic strength f_k = K·f_b^0.7·f_m^0.3 (§3.6.1.2), slenderness capped at 27 (§5.5.1.4) and vertical load resistance (§6.1.2). Used on

EN 1997-1Standard · Geotechnical design

Bored piles: set R4 partial factors (γ_b 2.0, γ_s 1.6), no load testing. The weakest calculation in the tool, and flagged as such. Used on

EN 206Standard · Concrete: specification, performance, production and conformity

Exposure classes. The XF freeze-thaw classes are explicitly excluded: water does not freeze in a structure here, and carrying them would add cover and cement for nothing. Used on

EN 338Standard · Structural timber: strength classes

C24, D30 and D40 classes: characteristic bending strength and mean modulus. Used on

EN 771Standard · Aggregate concrete masonry units

Normalised unit strength f_b and unit group, which set the K factor in EN 1996. Used on

External worksWork package

Yard, driveway, drainage, water and power connections at the plot boundary. Used on

Fair-faced block, no renderSpecification choice · Wall finish

The first line dropped when a budget tightens. It demands careful blockwork and struck joints, and the wall stays porous: avoid it on an elevation that takes driven rain. Used on

Fired brick 22 × 10.5 × 10.5Specification choice · Wall construction

Locally fired, cheaper but very uneven: strength varies threefold between kilns. Used on

Fired brick, double leaf (22 cm)Specification choice · Wall construction

Two bricks thick. Load-bearing over several storeys, but twice the brick count. Used on

Flat, sound groundSpecification choice · Site conditions

Minimal earthworks. Used on

Floor finishSpecification choice

Ceramic tiling dominates; a smoothed screed is still common in self-build. Used on

Floor tilingMeasured work · Finishes

Tiles, adhesive and grout on screed. Used on

Foundation typeSpecification choice

Driven entirely by the ground. On sandy, sloping or low-lying sites a soil survey is not optional. Used on

Galvanised sheetSpecification choice · Roof

The most widespread solution in the DRC: light, quick to fix, cheap. Used on

Gas water heaterSpecification choice · Hot water

Instant, and independent of both the grid and the generator, which is its main attraction here. You still have to handle the bottles, and proper ventilation is not optional. Used on

Gentle slopeSpecification choice · Site conditions

Moderate cut and fill. Used on

GlazingSpecification choice

Double glazing only pays off alongside permanent air conditioning. Used on

Grid onlySpecification choice · Power supply

Public connection with no backup. Used on

Grid plus backupSpecification choice · Power supply

Changeover, batteries and priority circuits. Used on

Ground floorSpecification choice

A ventilated void protects against rising damp, which is common in the rainy season. Used on

Ground-bearing slabMeasured work · Substructure

Floor slab cast over compacted hardcore. Used on

Hollow block 10 × 20 × 40Specification choice · Wall construction

Internal partitions only, never load-bearing. Used on

Hollow block 15 × 20 × 40Specification choice · Wall construction

The standard load-bearing wall unit in the DRC, for one or two storeys. Used on

Hollow block 20 × 20 × 40Specification choice · Wall construction

Retaining walls, exposed façades, multi-storey blocks. Used on

Hollow block 25 × 20 × 40Specification choice · Wall construction

Retaining and multi-storey load-bearing construction. Used on

Hollow half block 15 × 20 × 20Specification choice · Wall construction

For wall ends, window reveals and closing courses. Used for a whole wall it takes twice the units of a 400 mm block, so a dearer wall and twice the joints. Used on

Hollow half block 20 × 20 × 20Specification choice · Wall construction

For wall ends, window reveals and closing courses. Used for a whole wall it takes twice the units of a 400 mm block, so a dearer wall and twice the joints. Used on

Hot waterMeasured work · Finishes

Hot water, sized on the number of people. Solar costs more to buy and nothing to run. Used on

How the work is deliveredSpecification choice

Self-building saves the contractor’s margin, at the cost of your time and the risk. Used on

IEC 60364Standard · Low-voltage electrical installations

What an installation contains beyond its points: protection (§4-41) and an earthing arrangement (§5-54). Used on

Isolated pad footingsSpecification choice · Foundation type

Under columns only, with ground beams. Economical on good ground. Used on

LabourCost group

The people who build it: labourers, masons, carpenters, steelfixers, electricians, plumbers, tilers, painters and the site foreman. Used on

Laminated safety glassSpecification choice · Glazing

Slows break-in and does not shard when broken. Used on

Large-format porcelainSpecification choice · Floor finish

Harder, dearer, more demanding to lay. Used on

Load-bearing masonrySpecification choice · Structural system

No frame. Simple and cheap, but limited in span and height. Used on

Local timberSpecification choice · Doors and windows

Cheapest. Needs regular maintenance and termite treatment. Used on

Louvre (naco) windowsSpecification choice · Glazing

The commonest glazing in this climate: adjustable blades, permanent ventilation without opening up, and a broken blade costs a few dollars to replace. They seal badly, though, and they lift out from outside. Used on

Made ground or old fillSpecification choice · Site conditions

Many urban plots are old gullies that were tipped into. You dig down to natural ground or you pile, and without a soil test you do not know how deep. This is the case that most justifies an investigation. Used on

Main contractorSpecification choice · How the work is delivered

A single point of contact, 10–20% margin. Used on

Mains onlySpecification choice · Water supply

Connection to the public water main, no backup. Used on

Mains plus boreholeSpecification choice · Water supply

Dual supply with changeover. Used on

Masonry and structureWork package

Cement blocks, reinforced concrete columns and beams, ring beams, floor slabs. Used on

Masonry wallMeasured work · Superstructure

One wall, or a set of walls of the same type. Deduct the openings. Used on

Natural stone or hardwoodSpecification choice · Floor finish

High end, largely imported. Used on

Natural ventilationSpecification choice · Ventilation and cooling

Cross-ventilation only. Used on

NoneSpecification choice · Hot water

Common in economy housing. Used on

None (exposed structure)Specification choice · Ceilings

Cheapest, least comfortable. Used on

Off-grid (solar)Specification choice · Power supply

Independent installation, heavier sizing. Used on

Package treatment plantSpecification choice · Sanitation

Compliant discharge, needed for an apartment block or hotel. Used on

Pad footingsMeasured work · Substructure

Footings under columns. The size is designed from the load and the ground’s bearing capacity, not asked for. Used on

PaintingMeasured work · Finishes

Acrylic paint on render, primer included. Used on

Painting and final finishesWork package

Preparation, primer, internal and external paint, final clean. Used on

PavingMeasured work · External works

Yard, drive or apron, concrete on a gravel sub-base. Used on

Piers or pilesSpecification choice · Foundation type

Very poor ground or a high water table: go down to find bearing. Used on

PilesMeasured work · Substructure

Bored piles. Without a borehole log this is an order of magnitude only: capacity depends on the ground profile with depth, which this tool does not know. Used on

Plant and equipmentCost group

Equipment hired or written down on site, and the fuel that runs it. Used on

Plaster, screed and floor finishesWork package

Internal and external plaster, screeds, floor tiling and wall tiling. Used on

PlumbingMeasured work · Finishes

Water points and sanitary ware. A mains connection is not included: most plots do not have one. Used on

Plumbing and sanitary wareWork package

Supply and waste pipework, septic tank, sanitary fittings, water tank. Used on

PlywoodSpecification choice · Ceilings

The common, economical solution. Used on

Power generationMeasured work · External works

Generator, solar or both, sized on the building’s own load. Nothing is assumed to be connected: here you make your own power. Used on

Power supplySpecification choice

A grid connection alone is rarely enough: outages are a daily event across most of the countries covered. Used on

Pre-painted sheet or metal tileSpecification choice · Roof

Better corrosion resistance and noticeably cooler underneath. Used on

Professional fees and chargesCost group

What you pay to be allowed to build and to have it properly designed. Nearly all of it falls due before the first block is laid. Used on

PVCSpecification choice · Doors and windows

Imported, seals well, can distort in extreme heat. Used on

PVC panellingSpecification choice · Ceilings

Washable and unaffected by damp. Used on

Raft foundationMeasured work · Substructure

A thick slab under the whole building, for ground that cannot carry isolated pads. Used on

Raft slabSpecification choice · Foundation type

Soft or variable ground: a reinforced slab over the full footprint. Used on

Reinforced concrete flat slabSpecification choice · Roof

Allows a future storey and an accessible terrace. Waterproofing is essential. Used on

Reinforced concrete frameSpecification choice · Structural system

Concrete frame with block infill. The regional standard. Used on

Render and plasterMeasured work · Finishes

Cement render on masonry, internal or external. Used on

Restricted accessSpecification choice · Site access

Last stretch by wheelbarrow or head-load. Used on

RICS NRM 1Standard · Order of cost estimating and cost planning for capital building works

What the estimator does: an elemental cost per m², before the project is drawn. Used on

RICS NRM 2Standard · Detailed measurement for building works

What the bill of quantities does: measurement, once the dimensions are known. The rule that the two must be cross-checked comes from here. Used on

Rocky groundSpecification choice · Site conditions

Excellent bearing, but every cubic metre of excavation is broken out with a breaker or a sledge. The earthworks can cost more than the footings that go in them. Used on

RoofSpecification choice

A flat slab lets you add a storey later, but costs close to double a sheet roof. Used on

Roof coveringMeasured work · Roof

Structure and covering, from the plan area and the pitch. Used on

Roof structure and coveringWork package

Timber or steel roof structure, sheet or tile covering, gutters and downpipes. Used on

Rubble stone footingMeasured work · Substructure

Mortared stone laid in the trench. No reinforcement and no formwork: the width is limited by the 45° load spread, so a wide footing is necessarily a deep one. Used on

Rubble stone footingsSpecification choice · Foundation type

A trench filled with mortared stone. No reinforcement, so the width is limited by the 45° load spread and a wide footing is necessarily a deep one. Common where stone is local and cement is dear. Used on

SanitationSpecification choice

There is almost no sewer network in the DRC: a septic tank is the rule. Used on

Septic tank and soakawayMeasured work · External works

A masonry tank and a drainage field, sized to EN 12566-1. It is the soakaway that fails, and it fails because nobody sized it. Used on

Sewer connectionSpecification choice · Sanitation

Rare, only in a few central neighbourhoods. Used on

Single glazingSpecification choice · Glazing

The local standard. Used on

Site accessSpecification choice

If a lorry cannot unload on the plot, everything is carried by hand. Used on

Site conditionsSpecification choice

Slope, water, rock and fill: the four things that blow a foundation budget. Used on

Slab on gradeSpecification choice · Ground floor

Slab cast on compacted hardcore. The cheapest option. Used on

Smoothed screedSpecification choice · Floor finish

Floated concrete, sometimes painted. Used on

Soakaway pitSpecification choice · Sanitation

Minimal and cheap, but contaminates groundwater. Avoid near a borehole. Used on

Solar water heaterSpecification choice · Hot water

Higher up-front cost, no running cost. Used on

Solid block 15 × 20 × 40Specification choice · Wall construction

Twice the strength of hollow at the same thickness: the answer when you cannot go thicker. Used on

Solid reinforced slabSpecification choice · Upper floors

Cast on formwork. Strong, heavy, propping-intensive. Used on

Split air conditioningSpecification choice · Ventilation and cooling

Needs dedicated circuits and backup power. Used on

StaircaseMeasured work · Superstructure

A reinforced concrete stair. The steps, the going and the waist are designed, not asked for. Used on

SteelSpecification choice · Doors and windows

Highly resistant to break-in, prone to corrosion. Used on

Steel frameSpecification choice · Structural system

Long spans and fast erection. Expensive and import-dependent. Used on

Steep slopeSpecification choice · Site conditions

Retaining walls and stepped foundations. Used on

Stone or brick claddingSpecification choice · Wall finish

On visible façades, usually partial. Used on

Strip footingMeasured work · Substructure

Reinforced concrete cast in the trench, under the load-bearing walls. Used on

Strip footingsSpecification choice · Foundation type

Stable bearing ground. The most common solution in the DRC. Used on

Structural steel frameMeasured work · Superstructure

Steelwork, measured by mass. Fabrication and erection weigh more than the steel itself. Used on

Structural systemSpecification choice

A column-and-beam frame is the norm above one storey, or wherever you want large openings. Used on

Sun-dried earth brick (adobe)Specification choice · Wall construction

The commonest rural construction and the cheapest there is: the material is underfoot. Very weak in compression and destroyed by water, so a generous roof overhang and a hard plinth are not optional. A well-protected adobe wall lasts generations; a badly protected one does not survive two rainy seasons. Used on

Supervised self-buildSpecification choice · How the work is delivered

You buy the materials and pay each trade directly. Used on

Surface drainageMeasured work · External works

A masonry channel round the plot. Not a comfort: roof water nobody channelled is what undermines a footing. Used on

Suspended plasterboardSpecification choice · Ceilings

Neat finish, recessed lighting, space for services. Used on

Suspended slabMeasured work · Superstructure

Reinforced concrete floor or roof terrace. Used on

Tanker-delivered storageSpecification choice · Water supply

No borehole possible: large storage and a high running cost. Used on

Textured renderSpecification choice · Wall finish

Hides imperfections and weathers better on façades. Used on

ThatchSpecification choice · Roof

Cheapest and coolest: thatch insulates far better than a metal sheet. But it burns, it houses vermin and it is redone every five to eight years. Budget the renewal, not just the first roof. Used on

Timber floorSpecification choice · Upper floors

Light and quick, but termite-prone unless treated. Used on

Tinted or reflective glazingSpecification choice · Glazing

Cuts solar gain, and with it the cooling load. On a west elevation it pays for itself in electricity long before it wears out. Used on

Transport and deliveryCost group

Getting materials to site, including the last kilometre, which is often the dearest. Used on

Upper floorsSpecification choice

Only applies to buildings with more than one storey. Used on

Ventilated voidSpecification choice · Ground floor

Raised, ventilated floor: essential on damp ground. Used on

Ventilation and coolingSpecification choice

A good ceiling and cross-ventilation often beat an undersized air-conditioning system. Used on

Very difficult accessSpecification choice · Site access

Landlocked plot: handling becomes a cost line of its own. Used on

Wall constructionSpecification choice

The 15 cm block is the DRC load-bearing standard. The 10 cm block is for partitions only. Used on

Wall finishSpecification choice

Wet-room tiling is counted separately from the general wall treatment. Used on

Water supplySpecification choice

The public network is intermittent in most neighbourhoods: plan for storage. Used on

Wet or flood-proneSpecification choice · Site conditions

Fill, drainage and a raised floor are mandatory. Used on

Every definition is the one already sitting beside the term in the engine, not a second version written alongside it: correcting one corrects the other.