Design and drawing terms, defined plainly

A colour guideline that gives about 60% of a room to a dominant colour, 30% to a secondary colour and 10% to an accent.

The dominant share usually goes to walls and large floor areas, the secondary to furniture and textiles, and the accent to cushions, art or a single piece. Treat it as a starting point for balance rather than a fixed formula.

See also: Complementary colours, Hue, Value, Mood board

Directional light used to pick out a particular object or surface, such as artwork, shelving or a textured wall.

For a feature to stand out, the light on it is commonly set at around three to five times the level of the light around it. Narrow-beam spotlights, picture lights and LED strips are typical sources.

See also: Ambient lighting, Task lighting, Layered lighting, Beam angle

The general, even light that fills a room and lets you move around it safely and comfortably.

Ceiling fittings, wall washers and indirect light bounced off the ceiling are typical sources. Living spaces are commonly lit to around 100–300 lux of ambient light, with task and accent lighting added on top.

See also: Task lighting, Accent lighting, Layered lighting, Lux

A rendering effect that darkens creases, corners and the places where objects meet, imitating how less ambient light reaches those areas.

In real-time 3D it is usually calculated in screen space as an approximation; it adds depth and grounds furniture on the floor without the cost of full global illumination.

See also: Global illumination, Real-time rendering, Bloom

The measurement of human body dimensions, used to size furniture, worktops, walkways and reach zones so they suit the people who use them.

Typical seat heights of 430–480 mm (17–19 in), dining table heights of 720–760 mm (28–30 in) and kitchen worktops of about 900 mm (36 in) all come from anthropometric data.

See also: Clearance, Circulation, Worktop

The moulded trim that frames a door or window opening and covers the joint between the frame and the wall.

Domestic architraves are commonly 50–100 mm wide. They are often chosen to match the skirting profile so the joinery reads as one set.

See also: Skirting, Cornice, Dado rail

The angle of the cone of light a lamp or fitting gives out, measured between the points where intensity falls to half its peak.

Narrow spots of roughly 10–25° suit accent lighting; medium beams of about 25–40° and wide floods of 40–60° or more spread light for general use.

See also: Accent lighting, Lumen, Lux

A list of the items and quantities needed to build or furnish a design, such as furniture, flooring area, paint and doors.

Floor finishes are usually ordered with a waste allowance, commonly 5–10% for straight lay and more for diagonal or herringbone patterns. Paint is estimated for two coats.

See also: Specification, FF&E, Schedule

A rendering effect that lets very bright areas, such as lamps or sunlit windows, glow softly into the pixels around them.

Used lightly it suggests the brightness of a light source; too much makes an image look hazy.

See also: Ambient occlusion, Colour grading, Real-time rendering

A decorative moulded disc fixed to the ceiling, usually at the centre of a room, from which a pendant light hangs.

Plaster ceiling roses are common in period homes and are often restored alongside the cornice.

See also: Cornice, Picture rail, Reflected ceiling plan

A measurement taken from the centre of one element, such as a wall or opening, to the centre of another.

Centre-line dimensions are useful for setting out structure, but room sizes quoted this way include half of each wall thickness, so always check whether a drawing uses centre-line or clear dimensions.

See also: Clear dimension, Datum, Scale, Plan

The routes people take to move into, through and between spaces, including corridors, stairs and paths across rooms.

Corridors in homes are commonly at least 900 mm (3 ft) wide; 1,050–1,200 mm (42–48 in) is more comfortable where people pass each other. Keep main routes clear of furniture and door swings.

See also: Clearance, Zoning, Sightline, Anthropometrics

A measurement of the usable space between finished surfaces, such as from the face of one wall to the face of the opposite wall.

Clear dimensions are what matter when fitting furniture, kitchens and wardrobes. Allow for skirting and wall finishes, which can take 10–25 mm off each side.

See also: Centre-line dimension, Clearance, Measured survey

The free space that needs to be left around furniture, fixtures and appliances so they can be used and passed comfortably.

Common figures: 900 mm (36 in) behind dining chairs to a wall, 400–450 mm (16–18 in) between a sofa and coffee table, 600–700 mm (24–28 in) beside a bed, and 1,000–1,200 mm (40–48 in) between facing kitchen runs.

See also: Circulation, Clear dimension, Anthropometrics, Work triangle

Adjusting the overall colour, contrast and tone of a render or photograph to give it a consistent look or mood.

Warm grades suit evening and residential scenes, cool grades read as crisp and modern; small adjustments usually look more natural than strong ones.

See also: Bloom, Colour temperature, Real-time rendering

A score from 0 to 100 describing how faithfully a light source shows colours compared with a reference light of the same colour temperature.

A CRI of 80 or more is the usual minimum for interiors; 90 or more is preferred in kitchens, bathrooms and anywhere skin tones, food or finishes need to look true.

See also: Colour temperature, Lumen, Task lighting

A measure, in kelvin (K), of how warm or cool white light appears, from amber-toned low values to bluish high values.

Homes typically use warm white of 2,700–3,000 K; neutral white of about 4,000 K suits kitchens, utility rooms and workspaces; 5,000–6,500 K resembles daylight.

See also: Colour Rendering Index (CRI), Ambient lighting, Undertone

Pairs of hues that sit opposite each other on the colour wheel, such as blue and orange, and look more intense when placed together.

In interiors one complementary colour is usually kept dominant and the other used sparingly as an accent.

See also: Hue, Saturation, 60-30-10 rule

A moulding that runs along the junction between the top of a wall and the ceiling.

Plain coving is a simple concave form; ornate plaster cornices are common in period rooms and are best repaired rather than replaced.

See also: Ceiling rose, Picture rail, Architrave, Skirting

A horizontal moulding fixed to a wall at roughly waist height, often dividing two finishes and originally protecting the wall from chair backs.

Dado rails are typically set about 900–1,000 mm (35–39 in) above the floor, or close to a third of the wall height in rooms with tall ceilings.

See also: Wainscoting, Picture rail, Skirting

A fixed reference point, line or level from which other dimensions and heights on a drawing are measured.

Interior drawings often take the finished floor level as the datum, written as FFL ±0.000, with ceiling and sill heights measured from it.

See also: Finished floor level (FFL), Section, Centre-line dimension

A written summary of what a project must achieve, covering the client's needs, the spaces involved, priorities, constraints and budget.

A good brief separates must-haves from nice-to-haves and is reviewed and agreed before concept design begins.

See also: Mood board, Measured survey, Specification

Drawing Exchange Format, an open CAD file format created by Autodesk for exchanging 2D and 3D drawing data between programs.

DXF files keep geometry on named layers, so walls, openings and furniture can be switched on and off separately in the receiving CAD program.

See also: GLB, Plan, Scale

A flat, scaled drawing of a vertical surface, such as an interior wall, viewed straight on without perspective.

Interior elevations are commonly drawn at 1:20 or 1:50 and show heights of doors, windows, joinery, sockets and finishes.

See also: Plan, Section, Scale, Datum

A way of flattening a full 360° by 180° view onto a single rectangular image with a 2:1 width-to-height ratio.

It is the standard format for 360° panoramas; viewers wrap the image back onto a sphere so you can look around.

See also: Panorama, Field of view, Real-time rendering

Short for furniture, fixtures and equipment: the movable or loose items in an interior, as distinct from the building fabric and fixed services.

FF&E is usually scheduled and specified separately, with each item given a code, supplier, finish, quantity and lead time.

See also: Schedule, Specification, Bill of materials

The angle of a scene that a camera, real or virtual, takes in from one position.

Interior renders often use a horizontal field of view of about 60–90°; much wider angles fit more of a room in but stretch objects near the edges.

See also: Panorama, Equirectangular projection, Sightline

The height of the top surface of a completed floor, including its final covering, used as a reference for other heights.

Changes in floor finish thickness between rooms, such as tile next to carpet, need thresholds or levelling so FFLs line up.

See also: Datum, Section, Elevation

The feature in a room that draws the eye first, such as a fireplace, a view, a large artwork or a statement light.

Most rooms work best with one clear focal point, with furniture arranged to face or frame it.

See also: Sightline, Accent lighting, Zoning

The binary form of glTF 2.0, an open 3D file format that packs geometry, materials and textures into a single file.

GLB files open in many 3D programs, game engines and web viewers, which makes them a practical way to share furniture or whole rooms.

See also: DXF, PBR material, Real-time rendering

Lighting in a render that accounts for light bouncing between surfaces, not only light arriving directly from a source.

Bounced light is what makes a sunlit floor tint nearby walls; calculating it fully is expensive, so real-time engines approximate it.

See also: Path tracing, Ambient occlusion, Real-time rendering

A zigzag pattern made by laying rectangular blocks at right angles to each other, with the end of each block meeting the side of the next.

Herringbone is laid with square-ended blocks; chevron uses blocks cut at an angle, commonly 45°, so the points meet in a clean line. Both need a larger waste allowance than straight lay.

See also: Parquet, Bill of materials, LVT

The quality that names a colour family, such as red, green or blue, independent of how light or intense it is.

See also: Saturation, Value, Undertone, Complementary colours

A lighting approach that combines ambient, task and accent light, each on separate control, so a room works for different activities and moods.

Separate circuits or smart controls and dimmers let each layer be used on its own or together.

See also: Ambient lighting, Task lighting, Accent lighting

A scale from 0 (absolute black) to 100 (perfect white) showing how much visible light a colour or surface reflects.

Bright whites are usually 80 or above. A difference of about 30 points between adjoining surfaces is a commonly used guide for visual contrast, for example for people with sight loss.

See also: Value, Lux, Undertone

The unit of luminous flux, describing the total amount of visible light a lamp gives out in all directions.

A traditional 60 W incandescent bulb gives roughly 800 lumens; an LED lamp of about 8–10 W gives a similar output.

See also: Lux, Beam angle, Colour temperature

The unit of illuminance, equal to one lumen per square metre, describing how much light falls on a surface.

Typical targets: around 100–300 lux for general living areas, 300–500 lux on kitchen worktops and for reading, and about 500 lux for desk work.

See also: Lumen, Task lighting, Ambient lighting

Luxury vinyl tile, a layered vinyl floor covering made as planks or tiles with a printed design that imitates wood, stone or ceramic.

The clear wear layer is commonly about 0.3 mm for domestic use and 0.55 mm or more for heavier commercial use. LVT is water-resistant and warmer underfoot than tile.

See also: Parquet, Herringbone, Terrazzo

An accurate record of an existing space, taking room sizes, wall thicknesses, openings, heights and service positions on site.

Laser measures are standard; diagonals across each room are worth taking to check for walls that are not square.

See also: Clear dimension, Design brief, Plan

A thin cement-based coating, applied by trowel in several layers and then sealed, that gives a seamless concrete-like finish to floors and walls.

It is typically built up to about 2–3 mm thick, so it can often go over a sound existing surface; wet areas need a suitable sealer.

See also: Terrazzo, Splashback, Zellige

A collage of images, colours, materials and textures that sets out the intended look and feel of a design before detailed work begins.

See also: Design brief, 60-30-10 rule, Undertone

A symbol on a plan that shows the direction of north, so readers can understand orientation and where sunlight will fall.

In the northern hemisphere south-facing rooms get the most direct sun; in the southern hemisphere it is north-facing rooms.

See also: Plan, Scale, Reflected ceiling plan

An image with a very wide view; in interior visualisation it usually means a full 360° image you can look around in a viewer.

See also: Equirectangular projection, Field of view, Real-time rendering

Flooring made from small blocks or strips of wood laid in a geometric pattern, such as herringbone, chevron or basketweave.

Solid parquet blocks are typically 14–22 mm thick; engineered versions have a hardwood top layer on a stable core.

See also: Herringbone, LVT, Skirting

A rendering method that follows many random paths of light through a scene to produce physically accurate lighting, shadows and reflections.

It is slower than real-time rendering and is usually used for final photoreal stills, with each image refined over many samples.

See also: Global illumination, Real-time rendering, PBR material

A physically based rendering material, described by properties such as base colour, roughness and metalness so it reacts to light realistically.

Normal maps add surface detail such as wood grain or tile joints without extra geometry.

See also: GLB, Path tracing, Real-time rendering

A moulding fixed horizontally near the top of a wall, from which pictures can be hung on hooks and wires without making holes in the plaster.

Picture rails are commonly set about 300–500 mm (12–20 in) below the ceiling.

See also: Dado rail, Cornice, Ceiling rose

A scaled drawing of a space seen from directly above, as if cut horizontally at about 1–1.5 m above the floor.

Floor plans show walls, openings, door swings, fixed fittings and, where useful, furniture and dimensions.

See also: Elevation, Section, Reflected ceiling plan, Scale

The solid fill or hatch used on a plan or section to show walls and other elements cut through by the drawing plane.

Filling cut walls makes the layout easy to read at a glance; different hatches can tell new walls from existing ones.

See also: Plan, Section

Drawing a 3D scene fast enough, usually 30 to 60 frames per second, that you can move around and change it interactively.

Real-time engines use approximations such as screen-space ambient occlusion so scenes stay responsive on ordinary hardware.

See also: Path tracing, Ambient occlusion, Global illumination, Bloom

A drawing of the ceiling shown as if reflected in a mirror on the floor, so it lines up with the floor plan below.

It shows light fittings, switching, ceiling heights, bulkheads, vents and smoke detectors.

See also: Plan, Ceiling rose, Layered lighting

The intensity or purity of a colour, from a vivid pure hue to a muted, greyed version of it.

Large surfaces usually read stronger than a small sample, so wall colours are often chosen a step less saturated than first intended.

See also: Hue, Value, Undertone

The ratio between a measurement on a drawing and the real size it represents, such as 1:50, where 1 mm on paper equals 50 mm in reality.

Common interior scales are 1:100 for general plans, 1:50 for room plans, 1:20 for elevations and joinery, and 1:5 for details. The imperial 1/4 in = 1 ft is 1:48.

See also: Plan, Elevation, Centre-line dimension

A table on a drawing or in a document that lists repeated items, such as doors, windows, finishes or fittings, with their sizes and details.

Each item is given a reference that appears on the plans, so the drawing stays uncluttered.

See also: Specification, FF&E, Bill of materials

A drawing that shows a building or object as if sliced vertically, revealing heights, floor and ceiling build-ups and the relationship between levels.

See also: Plan, Elevation, Datum, Poché

The line of view from a particular position, such as the front door or a sofa, used to decide what people see first and what should be screened.

See also: Focal point, Circulation, Zoning

A board fixed along the base of a wall where it meets the floor, covering the joint and protecting the wall from knocks.

Heights commonly range from about 70 mm (3 in) in modern homes to 150–220 mm (6–9 in) or more in period rooms with tall ceilings.

See also: Architrave, Dado rail, Cornice

Checking finished work for defects, such as chipped paint, misaligned doors or missing fittings, and listing them for the contractor to put right.

See also: Specification, Schedule, FF&E

A document that defines exactly which products, materials, finishes and standards of workmanship are to be used in a project.

A specification usually names product codes, colours, sizes and installation notes so contractors can price and build consistently.

See also: Schedule, Bill of materials, FF&E, Design brief

A wipeable, water-resistant panel or tiled area on the wall behind a sink, hob or basin.

Splashbacks range from a low upstand of about 100 mm to a full panel between worktop and wall units; behind a hob the material must suit the heat.

See also: Worktop, Zellige, Microcement

Focused light aimed at an area where a specific activity happens, such as a worktop, desk, mirror or reading chair.

Task areas are usually lit to about 300–500 lux, with fittings placed to avoid casting your own shadow on the work.

See also: Ambient lighting, Accent lighting, Layered lighting, Lux

A composite finish of marble, stone or glass chips set in a cement or resin binder, then ground and polished smooth.

It is available poured in place or as pre-cast tiles and slabs, and is very durable on floors.

See also: Microcement, LVT, Zellige

The subtle underlying colour in a paint or material, such as the green in a grey or the pink in a beige, that shows in certain light.

Comparing samples against pure white and viewing them in morning and evening light makes undertones easier to see.

See also: Hue, Colour temperature, Value

How light or dark a colour is, independent of its hue or saturation.

A mix of light, mid and dark values keeps a scheme from looking flat, even when the colours themselves are close.

See also: Hue, Saturation, Light reflectance value (LRV)

Panelling, traditionally timber, that covers the lower part of an interior wall, often finished with a dado rail at the top.

It commonly runs to about 900–1,200 mm (35–47 in) high, and sometimes to two thirds of the wall height in tall rooms.

See also: Dado rail, Skirting, Picture rail

A kitchen planning guide that connects the sink, hob and fridge so the distances between them are short but not cramped.

A common guide is that each side measures 1.2–2.7 m (4–9 ft) and the three sides total 4.0–7.9 m (13–26 ft), with no tall units or through routes cutting across it.

See also: Clearance, Worktop, Zoning, Circulation

The flat working surface fitted on top of kitchen base units, also called a countertop.

Standard worktops are about 600–650 mm (24–25.5 in) deep and finish at about 900–915 mm (36 in) above the floor; islands often overhang by 250–300 mm (10–12 in) for seating.

See also: Splashback, Work triangle, Anthropometrics

Handmade glazed terracotta tiles from Morocco, with irregular edges and surface variation that give an uneven, light-catching finish.

They are commonly about 100 × 100 mm (4 × 4 in), laid with tight joints; the variation between tiles is part of the look.

See also: Splashback, Terrazzo, Microcement

Dividing a space into areas for different activities, such as cooking, dining and relaxing, using layout, furniture, lighting and finishes.

Rugs, changes of floor finish, lighting and the backs of sofas can define zones in an open-plan room without walls.

See also: Circulation, Sightline, Focal point