Glossary

Whether a design moves us. It spans form and style (visual order — proportion, scale, colour, light), image (the impression a room gives) and meaning (the identity and memory it carries).

The paths people take to move through and between spaces. Good plans give circulation a clear, generous shape (typically 900 mm for primary paths, 600 mm for secondary) rather than leaving it as scraps between furniture.

An open-to-sky space enclosed by a building's rooms (aangan, nadumuttam, chowk). Both a climate device — bringing light and ventilation deep into the plan — and the clearest example of designing the void: an unroofed, unfurnished space at the heart of the house.

A stated description of the feeling and meaning a design aims for — calm retreat, lively gathering space, rooted or cosmopolitan. Paired with the functional programme, it gives a project a complete brief on both demands.

A written statement of a project's functional requirements — the activities to be housed, their space and storage needs, clearances, budget and code constraints. Formulated early in the process; the brief against which a design is tested.

A relationship from visual perception in which a foreground figure and a background ground are mutually defining. In interiors, solid elements (figure) and the space they enclose (ground) define each other; inverting the reading reveals the void as a designed shape.

The modernist maxim that a thing's shape should derive from its purpose. A useful corrective to pointless ornament, but only half the truth: delight and meaning are separate demands a designer must address deliberately.

Whether a design works. It bundles utility (supports the activity), comfort (thermal, visual, acoustic, ergonomic), safety, economy and sustainability. A room can satisfy four of these and fail on the fifth and still be non-functional.

The deliberate planning and shaping of the spaces inside a building, so that they shelter us, support our daily activities and express the ideas we live by. Broader than decoration: it begins with the shaping of space itself.

The three-dimensional volume of air enclosed by a building's floor, walls and ceiling — the prime material of interior design. The designer composes this volume, not merely the surfaces that bound it.

The way an interior expresses identity, memory and values — a reading corner, an heirloom lamp, a threshold tulsi. A design concern distinct from visual style, and what makes a room feel like it belongs to its occupants.

Positive space is occupied by solid elements (walls, furniture, columns); negative space is the empty volume between and around them — circulation, clearance, breathing room. Skilled designers compose the negative space as deliberately as the positive.

The fundamental substance a discipline works in. For the sculptor it is stone; for the interior designer it is space. Walls, finishes and furniture are means of giving that space a usable, expressive shape.

Designing for the material, energy and health consequences of an interior over its whole life — durable materials, low-energy systems, healthy indoor air, and reduced waste. Treated as part of function, not an optional extra.

Vitruvius's three requirements of good building — firmitas, utilitas, venustas (firmness, commodity, delight). The classical ancestor of the modern function-and-aesthetics standard, with meaning added as a distinct fourth concern.

Three-dimensional space with length, width and height. Thinking in volume (in section, not just plan) is what distinguishes designing a room from arranging a floor plan; ceiling height alone can change a room's whole character.

What was actually constructed, as opposed to what was drawn. In Indian practice the as-built room routinely differs from the brochure plan by tens of millimetres, which is why you always measure rather than trust the drawing.

A horizontal structural member that gathers the load of a slab and carries it to the columns. A down-stand beam crossing a ceiling is a strong clue that the wall beneath it is doing structural work.

A surface built up from several layers, each doing one job — e.g. a wall of structure, damp-proof course, concealed services, plaster and finish. No single material satisfies load, weather, heat, sound and appearance at once.

The hidden systems that make a space habitable — water supply, drainage, electrical power, ventilation/air-conditioning, gas and data. They run through chases, screeds, ceiling voids and shafts, and constrain the plan.

A groove cut into a wall or floor to bury a pipe or conduit, then filled over. Chasing into masonry is routine; chasing deep into an RCC column or beam is dangerous and needs engineering approval.

A vertical structural member that carries load from the beams down to the foundation. Its position in the grid is fixed and untouchable; you design the interior around it, never through it.

Electrical conduit buried in chases cut into masonry and plastered over, so no wiring shows on the finished wall. Because it is hidden, point positions must be fixed before plastering.

A fixed condition the design must obey rather than wish away — a column, the plumbing stack, the direction of daylight. Reading the constraints first is what lets a designer respond to the real room instead of a fantasy.

A thin waterproof band built into a wall near its base to stop ground moisture wicking up into the masonry by capillary action. A first line of defence against rising damp.

A single fixed reference point against which all levels are measured during a survey, so every step and floor build-up is recorded consistently. Without one, level changes become guesswork.

The permanent self-weight of a building — slab, walls, plaster, flooring, fixed furniture. It never changes and never goes away; an RCC slab alone weighs roughly 3 kN per square metre before finishes.

The metal board of MCBs (and often an inverter/UPS feed) from which a home's electrical circuits radiate. Locating it — and the meter and shafts — is part of reading a flat's services.

The set of surfaces — floor, up to four walls, and ceiling/roof — that wrap a structure to make a habitable room, separating inside from outside and one room from the next. What the body actually touches and sees.

The honest current state of a space — damp, cracks, seepage, poor finishes, level changes — recorded and photographed during the survey so the design can heal problems rather than paper over them.

A gypsum or PoP ceiling hung 200–450 mm below the slab soffit on a steel/G.I. frame. The plenum gap hides AC ducts, drains, wiring and recessed lights while presenting one clean, level plane below.

The final, visible surface of an assembly — paint, tile, stone, wallpaper, laminate. The interior designer works mostly this last millimetre, but it rests on, and depends on, every layer behind it.

An RCC skeleton of columns and beams that carries all the load, leaving the walls as non-structural infill. The norm in Indian apartments; it frees the interior plan because partitions can often be moved.

Sideways force on a building — wind, and far more seriously in India, earthquake shaking. Because most of the country lies in seismic Zones III–V, the structure must be tied together to resist horizontal forces, not just downward ones.

The variable, movable load a building must carry — people, furniture, a filling water tank, a crowd of guests. Indian residential floors are typically designed for about 2 kN per square metre (IS 875).

The continuous route every load must travel to reach the ground — slab to beam to column to foundation to soil. Break it anywhere (remove a column, cut a beam) and the building fails at that point.

A wall that is itself part of the structure, carrying the slab above down to the foundation. Common in older and low-rise Indian masonry homes; it cannot be removed without a structural engineer's intervention.

An accurate, on-site measurement of an existing space — every wall, diagonal, opening, height, level and service — trusted over any builder's drawing. The honest foundation a design is built on.

The compass direction a room or window faces, and the light it therefore receives — soft morning sun from the east, harsh hot glare from the west. Reading it decides where activities best sit, before any furniture is chosen.

A non-structural wall that only divides space, carrying no load but its own. In a framed building these can often be removed or moved — but only after confirming they are not secretly on the load path.

A vertical duct (often 450–900 mm wide) carrying supply risers and waste stacks between floors. In apartments it is fixed, so wet rooms are planned to come to it rather than the other way round.

A levelling course of lean concrete or mortar (about 40–75 mm) laid over the structural slab to correct its slope and bring the floor to the right level before the finish goes down. Drainage often hides within it.

The main vertical drainage pipe (usually 110 mm) that carries waste down through a building. Because drainage falls by gravity, the stack's position effectively pins where WCs, sinks and wet areas can go.

The clear distance a beam or slab crosses between its supports. It sets — and limits — how column-free an interior can be; a large open hall must be designed into the structure before casting, not carved out later.

A space with plumbing and drainage — bathroom, kitchen, utility, balcony. Wet areas should cluster near a common shaft and ideally stack vertically floor-over-floor so drainage runs stay short and reliable.

The room an object needs around it to actually be used — a dining chair's pull-out-and-sit zone, a wardrobe's door-swing and standing room. A second, invisible footprint, always larger than the object, that plans ignore at their peril.

How near or far two spaces should sit from each other based on how they are used — kitchen adjacent to dining, guest toilet reachable without crossing bedrooms. The relationships a bubble diagram captures and a plan must honour.

The measurement of the human body — heights, reaches, widths. The data an interior designer translates into the heights of counters, shelves and switches. Indian anthropometric data generally runs smaller than Western tables.

A loose, out-of-scale sketch of spaces as circles with lines showing desired adjacencies. Deliberately ugly: its only job is to fix relationships (kitchen by dining, parents away from noise) before any wall is drawn.

The minimum gap held around or between furniture so it can be used comfortably — e.g. ~900 mm behind a dining chair, 1050–1200 mm for a kitchen aisle, 600 mm beside a bed. Protected on a plan the way a structural dimension is.

A weighted scoring grid — criteria with weights down the side, alternatives across the top, scores totalled — used to choose among schemes. It does not mechanise taste; it makes the reasoning visible and defensible to a client.

Several genuinely different schematic schemes for the same brief, developed deliberately rather than refining the first sketch. Divergence before convergence: real rivals expose the trade-offs hidden in your favourite.

What the client tells you they want — usually vague, emotional and contradictory ('royal but minimal, and cheap'). The raw material from which the designer writes the disciplined programme; the client's voice, not yet a working document.

The single organising idea a whole scheme serves, expressible in one sentence ('calm grey shell, one warm timber heart'). Grown from the programme, not a mood board, it gives a design coherence and a test for every later decision.

The orderly, iterative sequence behind good design: define the problem, write the programme, develop a concept, explore alternatives, decide, refine, implement and re-evaluate — looping back as discoveries demand. Design is a process you can repeat, not a flash of inspiration.

The discipline of designing objects and spaces to fit the human body comfortably. If anthropometrics is the data, ergonomics is the decision — turning body measurements into a counter at the right height or a shelf within reach.

The test of whether a set of requirements actually fits the budget, the physical space and the rules before any design is committed. It is kinder, and far cheaper, to say no on the programme matrix than to demolish on site.

The arrangement of a kitchen's runs of counter — single-wall, parallel/galley, L-shape, U-shape or island — chosen to house a sound work triangle within the available space. Indian plans often add a wet/dry-kitchen split.

The architectural term for a scheme's central organising idea — essentially a synonym for the design concept. Often captured as a single diagram that every later move elaborates.

A point on the curve of human body sizes: the 5th percentile is a small body (only 5% are smaller), the 50th is average, the 95th is large. Designers size clearances for the 95th and reaches for the 5th — never the mythical 'average'.

The study of the distances people keep from one another — intimate, personal, social and public zones. In interiors, furniture spacing encodes these: sofas ~2.4–3.0 m apart invite conversation, while too much distance makes a room feel cold.

The arc of space a hand can cover, split into a comfortable inner zone (elbow bent, no strain) for daily-use items and a maximum outer reach for occasional things. Storing daily items in the comfortable zone is one of design's most useful rules.

The early design stage of block layouts, key moves and rough zones — enough depth to compare strategies, not finished detail. Developing alternatives only to schematic depth keeps you from falling in love with the wrong one too early.

The explicit boundary of what a designer will and will not do on a project — rooms covered, items included and excluded, who procures what. Vague scope is how both budgets and relationships collapse.

The craft of arranging activities, furniture and circulation within a space. It begins with relationships (a bubble diagram), not geometry, and only then fits those relationships to the real room.

Designing so a space serves the widest range of people — elders, children, wheelchair users — without special adaptation. Considers lower reaches, knee clearances, step-free thresholds and grab support as a matter of course.

The triangle joining a kitchen's three work centres — sink, stove and fridge. Each leg should run 1.2–2.7 m and the three total 3.6–6.6 m, with no through-traffic cutting across it, so cooking flows rather than treks.

Grouping a plan into areas by use and character — public vs private, wet vs dry, quiet vs active — so related activities sit together and incompatible ones are kept apart. The organising layer above individual rooms.

The distribution of visual weight so a composition feels settled, not tipping. Comes as symmetrical (mirror), asymmetrical (unlike elements of equal weight) and radial (around a centre). Visual weight grows with size, dark/saturated colour, texture and isolation.

A deliberate set of hue relationships from the colour wheel — monochromatic (one hue), analogous (neighbours), complementary (opposites), triadic (three evenly spaced). The scheme sets the hues; you still design the values and a distribution like 60-30-10.

A ring of hues that maps which colours are relatives and which are opposites. From it come the classic schemes — monochromatic, analogous, complementary, triadic — all defined purely by hue relationships.

Where a space sits on the spectrum from fully open to fully enclosed — terrace, verandah, courtyard, jaali room, solid room. A design choice matched to each activity, not a ranking.

The focal point — the one element that dominates and anchors the eye on entry, like a carved door or a feature wall. A room with none feels aimless; one with several competing feels chaotic. Usually one hero.

The overall shape and structure of a three-dimensional element — its contour, mass and the way it meets the light. The umbrella term for any element risen into the third dimension, from a chair to a whole room.

A proportion of roughly 1:1.618, where the smaller part relates to the larger as the larger relates to the whole. Not magic but a useful tool for keeping a design's parts in consistent relationship.

The pleasing sense of a whole, living in the tension between unity (things belonging together) and variety (enough difference to stay interesting). All-matching is dead; all-different is chaos.

The colour family a colour belongs to — red, blue, green — the name we usually mean by 'colour'. One of the three independent dimensions of colour, and usually the least decisive in a room.

Elements sized to the body — a 2.1 m door, a comfortable step, a 900 mm handrail, an 850 mm counter — so they feel natural to move through. The opposite of the deliberate awe of monumental scale.

A one-dimensional element with length and direction — a beam, a slim column, a curtain rod, the edge where wall meets floor. Vertical lines feel aspirational; horizontal lines feel restful.

A repeating motif. The same phenomenon as texture at a different scale: a pattern seen from far enough away dissolves into texture, so distance is the dial between the two.

A two-dimensional surface with shape and edge — a wall, floor, ceiling, partition or rug. The interior designer's main working material, because a room's surfaces are planes.

An element marking a position in space, with no length, width or direction — a single pendant light, a lone chair, a deity in a niche. The smallest unit of form; place one and a space organises itself around it.

The unit-free relationship of a part to the whole or of parts to each other — a ratio. Harmonious proportions feel resolved; arbitrary ones feel 'off' even when everything fits. The same for a model and a monument.

A chosen ratio family (whole numbers, root rectangles, the golden section) used repeatedly so the parts of a design agree with one another. A discipline for consistency, not a formula for beauty.

Visual movement created by repeating elements — repetition (a row of columns or jaali), alternation (ABAB), and gradation (a graded change in size or tone). The eye is led along.

How pure or greyed a colour is (also called chroma or intensity) — a vivid pure red versus a dusty greyed rose. Pull it to zero and every hue collapses to grey.

The size of something judged against a reference — usually the human body or surrounding elements. Where proportion is a ratio, scale answers 'how big, and against what?'

The act of giving a space an edge with planes, to varying degrees — a single plane suggests a zone, an L anchors a corner, parallel planes channel, a U shelters, four planes enclose. Defining space with the least mass that achieves the intended feeling.

Mirror balance — the same arrangement on both sides of a centre line. Formal, calm and ceremonial (a pooja niche flanked by two lamps), but stiff if overused.

Real, three-dimensional surface relief the hand can feel — handloom weave, lime plaster, split cane, raw Kota stone. Distinct from the printed look of texture.

The surface quality of a material — rough or smooth, soft or hard, matt or glossy. Read first with the eyes, it is what stops a room feeling flat and cold, and it is fundamentally an effect of light catching micro-relief.

The two forces harmony balances — unity (a shared palette, repeated forms, a consistent material story) holding a room together, and variety (deliberate difference) keeping it alive.

How light or dark a colour is, independent of its hue. The dimension that does most of a room's work: value contrast creates light, depth and form, while a muddle of mid-tones reads flat whatever the hue.

The printed appearance of texture on a dead-flat surface — a wood-grain laminate, a stone-look tile. It borrows the look without the feel, and behaves differently under raking light.

The guarding assembly along the open side of a stair or edge — a graspable handrail at ~900 mm plus vertical balusters spaced under 100 mm apart so a child's head cannot pass through.

A dropped border or box in a ceiling — a peripheral bulkhead runs a lowered band around a room's edge (hiding ducts and carrying cove light) while leaving the centre at full height.

A window hinged on one side that swings open like a small door, giving the full opening for ventilation — as opposed to a sliding, awning, fixed or bay window.

A surface layer fixed over a wall for looks or protection — wood veneer, laminate, stone or tile. Adds richness and durability but also thickness, weight and cost the design must allow for.

A ceiling broken into a grid of recessed panels (coffers), giving rhythm and a sense of crafted weight overhead.

An LED strip hidden in a stepped ceiling or wall recess so its light bounces off the surface and washes the room with a soft, sourceless, indirect glow.

The quarter-circle arc a hinged door sweeps as it opens — floor that must stay empty of furniture, never swing into a passage, and never clash with another door. It grows with the square of the door's width.

A lightweight partition of gypsum board fixed to a GI-stud frame. Fast, dry and hollow (easy to run services through), but weaker for hanging heavy loads and unsuitable for wet areas in its standard form.

One wall given a deliberately bolder treatment — stone, veneer, wallpaper, texture or strong colour — to carry a room's visual weight while the others stay quiet. Works only as the room's single emphasis.

The thin visible top layer of a floor — tile, stone, wood, terrazzo or carpet — laid on bedding over the screed. Chosen by matching cost, durability, maintenance, warmth and slip resistance to each room's life.

The useful horizontal distance one stair step carries you forward (the tread minus any nosing overlap). The 'T' in the 2R + T comfort rule.

A flat platform where a stair turns or breaks a long run — a place to change direction and to rest, sized at least the width of the stair.

The beam spanning the top of a door or window opening that carries the wall load above it across the gap.

Quarried floor and wall finishes — Kota, granite, marble, slate. Cool underfoot, durable and premium; marble in particular stains and etches, and all need periodic sealing.

The front edge of a stair tread that overhangs the riser below, adding a little foot room. A rounded, grippy nosing is far safer than a sharp edge.

The vertical face of a stair step — the height you lift your foot to the next tread. Comfortable at 150–190 mm; steeper is tiring and unsafe, and the NBC caps it for homes.

The bottom edge of a window. Its height tunes use: ~900 mm typical, lower for a view or seat, ~1200 mm over a kitchen counter, higher in a bathroom for privacy.

A 75–150 mm band running along the base of a wall that protects the vulnerable wall bottom from mop water and scuffs and hides the junction where floor meets plaster.

A door that runs sideways on a track, needing no swing space — the go-to for balconies and wardrobes. A pocket door is a sliding door that disappears into a hollow wall.

The underside of an overhead element — most often the underside of the RCC floor slab above, which becomes the room's bare ceiling when plastered and painted.

The horizontal surface of a stair step you plant your foot on. Wants to be about 250–300 mm so the whole foot, not just the toes, lands.

A dense, hard ceramic tile fired to near-zero porosity — the default Indian floor finish: cheap, durable, low-maintenance and endlessly varied, but slippery when wet unless a matt or anti-skid surface is chosen.

The face applied to a base wall — paint over putty, textured paint, veneer or laminate cladding, stone, wallpaper or tile — chosen for how the spot is used: tile to water, washable paint to traffic, the dramatic to a feature wall.

How many times the full volume of air in a room is replaced with fresh air in one hour (ACH). A bedroom is comfortable around 0.5 ACH; kitchens and bathrooms need far more.

The sum of the wattage of every appliance in a home. Because they never all run at once, the supply is sized on a realistic fraction of it - diversity - not the full total.

The consumer unit near a home's entrance where the single incoming supply is split into many circuits, each leaving on its own MCB, usually behind a whole-board RCCB.

The pipework that carries used water and waste away from fixtures. It works only by gravity, so it runs in large-bore pipes that must always slope downhill toward the stack.

The steady downhill fall given to a drain pipe - about 1:40 for a 110 mm soil pipe - so water and solids travel together. Too flat blocks; surprisingly, too steep also strands solids.

A dedicated conductor connecting every metal appliance body to a buried earth electrode, giving fault current a safe path to ground and letting the RCCB sense a leak.

The means of escape from a space - the route, distance and doors by which people leave safely in an emergency. Exit doors swing outward and stay unlocked and unobstructed.

A portable firefighting device mounted on escape routes and near hazards such as the kitchen and electrical panels, placed so a person can see and reach it on the path they would actually run.

Heating, ventilation and air-conditioning - the combined systems that keep indoor air at a comfortable temperature, replace stale air with fresh, and control humidity.

A miniature circuit breaker - the small switch protecting one circuit. It trips on overload or short-circuit to stop the cable overheating. It guards the wire, not the person.

India's collected rules for safe building (NBC 2016). An interior designer touches the parts on occupancy, means of escape, fire protection, ventilation and accessibility.

A water tank on the roof, filled by a pump, that feeds every fixture by gravity. The height of its water above a tap - the head - is what gives that tap its pressure.

A U or P shaped bend below a fixture that holds a permanent plug of water - the water seal - blocking foul sewer gas from rising into the room. Every fixture and floor drain needs one.

A wiring circuit that leaves the distribution board, runs to a string of points, and ends. Lights, sockets, the kitchen and each heavy appliance get their own, sized to the load.

The steepness of a ramp expressed as rise to length. The accessible maximum is 1:12 - twelve units of length per unit of rise - and gentler is always kinder to climb.

A residual-current circuit breaker (also ELCB) that senses current leaking to earth, through a person or fault, and cuts power in milliseconds. It guards the person against electric shock.

How much water vapour the air holds compared with the most it could hold at that temperature, as a percentage. High humidity stops sweat evaporating, so a room feels sticky and warmer than its actual temperature.

An air-conditioner in two parts: a quiet indoor unit that cools the room and a separate outdoor unit holding the noisy compressor, joined by refrigerant pipes. The common choice for Indian bedrooms.

The pressurised pipework that carries clean water from the tank to each fixture. Being under pressure, it can run in small-bore pipes that climb walls and turn corners freely.

The state in which a person feels neither too warm nor too cool. It depends on four things at once - air temperature, the radiant heat of surrounding surfaces, relative humidity and air movement - not on the thermostat alone.

A measure of cooling power, not weight - historically the heat needed to melt one ton of ice in a day, about 3.5 kW. A '1.5 ton' AC suits a typical 12-16 sq m bedroom.

How far a person must walk from the most remote point of a space to reach an exit. Codes cap it, because beyond a certain distance smoke overtakes you before you reach the door.

Designing a space so the widest range of people can use it without adaptation - ramps, level thresholds, wide doors, turning space and lever handles that help elders, parents and the injured alike.

A single thickened wall onto which all the plumbing fixtures of a bathroom, and ideally the kitchen, are clustered, so one set of pipes serves them with short runs and fewer joints to leak.

The optional dramatic layer that gives a room depth and intent - washing a textured wall, grazing art, glowing from a cove. What separates a room that is merely visible from one that feels composed.

Sound that travels through the air and any gap it finds - a neighbour's TV, voices, traffic - leaking under doors and through thin partitions. If light can get through a gap, so can sound.

The soft, general fill light that lets you see and move around a room comfortably - the background glow you stop noticing. Best delivered by cove light or several spread sources, not one harsh central fitting.

How widely a fitting throws its light. A narrow beam (around 24 degrees) makes a tight accent spot; a wide beam (60 degrees and up) gives a broad ambient wash. Match the beam to the job.

A band of high windows set near the ceiling. Because the light enters high, it reaches far across a room and washes the back wall - exactly where a low side window fails - while giving privacy.

CRI, a 0-100 score of how faithfully a light shows true colours against an ideal reference. Below ~80 skin looks sallow and food grey; aim CRI 90+ at the mirror, wardrobe, kitchen and art.

The hue of white light, measured in Kelvin - and named counter-intuitively, since a low number looks warm-amber and a high number looks cool-blue. It sets a room's mood, not its brightness.

Light around 5000-6500K - crisp, blue, daylight-like. Useful in a garage, utility area or for inspecting fine detail, but clinical and hospital-like if used in a living room.

A rough gauge of how well-daylit a room is - in practice judged by the window glass area as a fraction of floor area (aim ~10-20%). A higher factor means a brighter room, but says nothing about how deep the light reaches.

The direction a window faces, which sets the character of its daylight: in India north is soft and glare-free, east a gentle morning light, south strong but easily shaded, and west a harsh low afternoon glare.

Varying a light's output for control of brightness and mood. Needs a fitting and driver marked dimmable; the finest fittings dim-to-warm, drifting amber as they lower, like daylight at dusk.

The discomfort of a very bright patch sitting in a much darker field - a bare bulb or a lone bright window in a dark wall. Cured by contrast, not quantity: shield the source, wash the surrounding surfaces, light from two sides.

The unit of colour temperature. Warm 2700-3000K for relaxing spaces, neutral 3500-4100K for work, cool 5000-6500K only where raw clarity is needed. Keep one value consistent within a space.

A horizontal projection across a window at about door height; it shades the harsh lower light and, with a pale top, bounces daylight off the ceiling deeper into the room.

The total amount of light a fitting emits, printed on the box. Lumens describe the source; lux describes the result on a surface. With LEDs, read lumens for brightness, not watts.

The amount of light actually landing on a surface - one lumen spread over one square metre. You plan to a lux target on the page or counter (e.g. 300-500 lux for tasks), not to a lumen count in the air.

NRC, a 0 to ~1.0 rating of how much sound a material absorbs. Glass and tile sit near 0 (reflective); a thick acoustic panel approaches 1.0. A bare tiled room is near 0.05; rugs and curtains raise it fast.

The echo and ring of sound bouncing around inside a room. A long reverberation time (hard, tiled, empty rooms) sounds harsh and tiring; a short one sounds calm and clear. Shortened by adding soft, absorptive area.

Anything that controls direct sun at a window - a horizontal chajja or overhang for high south sun, vertical fins or a jaali for low east-west sun - letting daylight in while keeping heat and glare out.

The soaking-up of sound energy by soft, porous materials - rugs, curtains, upholstery, a soft ceiling, books - which turn it to a trace of heat instead of reflecting it. The cure for an echoey room.

Blocking sound from passing between spaces, achieved with three tools together: mass (heavy dense barriers), an air gap or decoupling so vibration cannot bridge, and sealing every gap. Different from absorption.

Sound that travels as vibration through the solid building itself - footsteps from above, a drilling neighbour, the lift. Soft furnishings do nothing for it; it needs decoupling and resilient layers.

Focused light delivered exactly where the eyes do demanding work - the kitchen counter, the study desk, the mirror. Placed to the side or front so the user's own head does not shadow the work.

Light around 2700-3000K - amber and gentle, flattering to skin, wood and fabric. The default for bedrooms, living and dining rooms, and the light that helps the body wind down in the evening.

A matt or textured floor finish that keeps its grip when wet - mandatory in bathrooms, balconies and around kitchen sinks, laid to a gentle slope toward the drain. Slip resistance outranks looks in any wet area.

How well a finish stands up to its specific abuse - water, scratches, impact, sun and foot traffic. A finish is only as good as the punishment its location hands out; the right durability is the durability that room demands.

A thin layer of genuine hardwood bonded to a stable cross-laminated plywood or HDF core. The core resists humidity-driven movement, making it the practical premium wood floor for most Indian homes - real wood that behaves.

A suspended POP or gypsum plane below the structural slab that hides ducts, wiring and beams and carries recessed and cove lighting. It adds drama and conceals services at the cost of ceiling height and money - use it where it earns its keep.

The visible, touchable surface of a room - the floor, wall, ceiling or counter. It greets the eye, takes the wear, soaks up spills and keeps costing money long after the contractor leaves, so it is chosen on four criteria, not looks alone.

The filler in the joints between tiles. Cheap cement grout is porous and yellows as it absorbs grime and mop water; quality epoxy grout and a colour close to the tile keep a floor looking clean. Large-format tiles need less of it.

A high-resolution photograph of wood sealed under a tough wear layer on an HDF board. Affordable, scratch-resistant and convincing to the eye, but not real wood and not waterproof - standing water swells the edges permanently.

The true cost of a finish across all the years it serves - purchase plus cleaning, re-sealing, repainting and eventual replacement. A cheap finish redone often can cost more than a durable one bought once; choosing on the initial quote alone is the common, expensive mistake.

How easily a finish cleans and how often it needs sealing, polishing or repainting - and whether it hides or flaunts dirt and hard-water stains. The quiet recurring tax of a surface, and a real concern in dusty, humid India.

Floor and wall finish cut from the earth - granite (near-indestructible), marble (gorgeous but soft and acid-sensitive), Kota and Kadappa (honest workhorses). Durable, cool underfoot and premium, but most types need sealing and periodic care.

How much light a paint bounces back, from matte to gloss. As sheen rises, washability rises but the ability to hide wall flaws falls - so sheen is chosen per room: matte for calm walls and ceilings, semi-gloss for kitchens and trim.

The cement-sand coat troweled onto brick or block to form the base of a wall finish. If it is hollow, cracked or still damp, nothing applied above it - putty, primer or paint - will hold.

The coat between putty and paint that seals the porous, alkaline wall surface and gives the topcoats something to grip. Skip it and even premium paint bonds poorly and fails early - one of the layers in the paint system.

How much grip a floor offers underfoot, especially when wet - the first criterion for any bathroom, balcony or kitchen floor. An anti-skid matt surface is safe where a glossy one becomes a hospital trip.

The health and environmental cost of a finish over its life - low-VOC, locally sourced and durable. The quiet fifth lens: a finish that lasts decades and off-gasses little is usually the greener and, over time, cheaper choice.

A thin slice of real wood (or a printed laminate imitating it) bonded to a board and used to panel a wall or furniture face. A warm, crafted feature-wall finish - best used on one accent wall, not the whole room.

A ceramic tile fired so dense it barely absorbs water - India's low-maintenance default floor. Glazed (GVT) carries the pattern in a thin top layer; double-charged and full-body run the colour deep so wear and chips barely show.

A fine white paste applied in two coats over rough plaster to fill its pits and ripples, then sanded glass-smooth. It is what makes premium paint actually look premium; without it, paint shows every flaw beneath.

The final styling layer of objects, art and plants that turns a furnished room into a personal home. The skill is mostly subtraction - editing to a few meaningful pieces, grouped with intent and breathing space, never the over-stuffed showcase.

Bringing living plants and natural elements indoors for calm, cleaner air and a connection to the outdoors. Works only when the plant is honestly matched to the light a spot actually gets - bright, medium or low.

The hard, dry pieces of furniture - wardrobes, shelving, chests, side and dining tables, the TV unit. They store or hold things up, and are judged on structure and joinery; they fail by wobbling or sagging.

The ratio of curtain fabric to window width - roughly 2 to 2.5 times the width so the curtain gathers into deep, rich folds. A curtain only as wide as its window hangs flat and looks mean; buy the fullness.

Light fittings chosen as objects as well as light sources - a pendant over the table, a chandelier scaled to the room, floor and table lamps that bring warm light down to human level. They earn their place lit and unlit.

Designing furniture to fit the human body and the activity - a seat about 450 mm high, a table about 750 mm with knee clearance. Get the dimensions wrong and the body knows at once; the piece either welcomes you or quietly fights you.

The thing a seating group is aimed at - a TV, a window with a view, a fireplace or a piece of art. Floated seating turned toward a clear focal point on a shared rug is what makes a sociable, intentional room.

The way furniture parts are joined. A glued, snug mortise-and-tenon or dowelled joint outlives one merely nailed or stapled. Open a drawer: dovetailed corners and a smooth glide signal care; stapled corners warn of a piece that will loosen in a year.

Factory-made, precise, repeatable furniture built from standard units - and, more broadly, multi-functional pieces (sofa-cum-bed, nesting tables, storage bed) that let a small flat do the work of a much larger home.

Fabric fibre grown from plants or animals - cotton and linen that breathe and suit Indian heat, silk for luxury, wool for warmth and rugs, jute for texture. Breathable and dye-rich, but they need more care than synthetics.

A measure of upholstery durability from the Martindale test - how many times a machine rubs the fabric before it wears through. About 15000 rubs suits light use; a daily family sofa wants 40000 or more of heavy domestic rating.

The styling principle that objects grouped in odd numbers - threes and fives - look relaxed and natural, while pairs and even rows feel stiff and symmetrical. The first move in arranging a vignette.

The movable fabric layer of a room - rugs, cushions, throws, curtains and upholstery - that adds warmth, colour, comfort and sound absorption, and can be swapped with the seasons far more cheaply than the hard finishes beneath.

Fabric fibre spun from petrochemicals - polyester, acrylic, nylon. Tough, cheap, colour-fast and stain-resistant, but it can feel hot against the skin and trap odour in a humid climate. Blends chase the best of both families.

The soft furniture - sofas, easy chairs, beds, the diwan - where a hidden timber or ply frame carries webbing, foam and fabric. You judge both the skeleton you cannot see and the comfort you can feel; it fails by going lumpy or creaky.

The fabric, padding and webbing that cover and cushion seating. Chosen for where it sits: a daily family sofa needs a tight weave with a high rub count and, ideally, washable loose covers; an occasional chair can be almost anything.

A small, composed grouping of objects on a shelf, console or table. Built with the rule of odds, triangulation and varied heights so a surface reads as composed rather than cluttered - the unit of good styling.

Curtains and blinds, which control light, give privacy, soften heat gain and absorb sound all at once. A heavy lined curtain is the cheapest acoustic fix most homes ever buy; sheers and drapes are layered for day and night.

One guiding sentence that captures the central design idea of a room and steers every later choice - calm or busy, warm or cool, the one material that ties it together. Small, but a ruler against which finishes, light and furniture are measured.

The moment a complete specification passes to the people who build it - the document and the meeting that let a contractor construct the designer's exact intent. The point at which a concept, fully written down, becomes a real room.

A written table listing every surface in a room - floor, walls, ceiling, feature wall - and against each the material, finish or colour, and area. So trades can divide the work and order quantities without guessing; each choice justified against use, durability, cost and concept.

FF&E - the movable layer of a room specified with the same rigour as the wiring: the sofa by rub count, the curtains by fullness, the rug by size, the art and plants. The schedule of everything the family actually touches.

A visual collage that gives a concept a face - a palette, key materials, a quality of light and a feeling, pinned together as images and samples. The compass a designer keeps in view while drawing, choosing and specifying the room.

A drawing of a room's ceiling as if mirrored down onto the floor, so every light fitting, cove and bulkhead is shown exactly where it will hang. The drawing on which the three lighting layers - ambient, task, accent - are placed.

Dividing a room into areas by activity - a conversation group, a dining zone, a circulation spine, a quiet corner - driven by the brief and a reading of the real space, so each part gets the daylight, adjacency and clearance it needs.

The complete, written, buildable account of a room - arranged plan, services, finish schedule, lighting plan and furnishings - detailed enough that a carpenter, electrician, painter and tailor can each build their part exactly as intended, without the designer in the room. The specification is the design, not the paperwork after it.