FAQ.

What people ask most, answered.

The questions designers and homeowners search for most, gathered from every guide page. Search them, or open any one to read its answer.

Search the questions

Survey Read the guide

How do you measure the square footage of a room?

Measure the length and the width of the floor and multiply them: a room 4.80 m by 3.60 m is 17.3 m², or about 186 sq ft (1 m² is 10.76 sq ft). Split an L-shaped or irregular room into rectangles, work out each one and add them. Measure between the finished walls, at floor level, and leave out chimney breasts and other projections.

How do you measure a room for a floor plan?

Sketch the room first, then measure clockwise from the door: each wall’s overall length, then the segments to and across every opening. Add the depth of recesses and projections, both diagonals to check the corners, and the ceiling, sill and door heights. A laser distance meter does it faster and more precisely than a tape.

How do you draw a floor plan from measurements?

Draw the longest wall first at scale, usually 1:50 for a room, then add the others in the order you measured them, checking each corner against the diagonals. Draw the walls with their thickness, place the openings by their distances from the corners, and finish with door swings and dimensions. In CAD, import a scanned or photographed sketch and set its scale from one known length before tracing.

What is a floor plan?

A floor plan, or plan, is a drawing of a room or building seen from above, as if cut horizontally about 1.2 m above the floor. It shows walls, doors, windows and fixed elements at scale, with their dimensions, and is the base for every other drawing of the project.

What is the standard ceiling height?

In most new homes, ceilings are between 2.40 and 2.60 m high; older houses often have 2.70 to 3.00 m or more on the main floors. Building rules set a minimum, commonly around 2.20 to 2.50 m for habitable rooms, but the figure varies by country, so check the local code. Always measure the real height in several places: floors and ceilings are rarely level.

What are as-built drawings?

As-built drawings record a building as it was actually built, including every change made on site, and are handed over at the end of a project. A measured survey of an existing building produces something similar, existing-condition drawings, which are the starting point for any new design.

What is LiDAR?

LiDAR (light detection and ranging) measures distances by sending out pulses of light and timing how long each takes to bounce back. Repeated thousands of times a second in every direction, it builds a 3D record of a space. Phones and tablets use a small LiDAR sensor; survey scanners use far more powerful ones.

Which iPhones have a LiDAR scanner?

The Pro and Pro Max iPhones have one, from the iPhone 12 Pro onward, as do iPad Pro models from 2020. The standard and Plus models do not. Apps built on Apple’s RoomPlan use it to scan a room and draw its floor plan.

What is Matterport?

Matterport is a platform for capturing buildings as navigable 3D models, often called digital twins, viewed online. It works with its own cameras, with some phones, and with laser scanners. Its measurements are only as reliable as the device used: a 360° camera capture is a good visual record, a laser scan a measured one.

What is a point cloud?

A point cloud is the raw result of a 3D scan: millions of measured points, each with its position and often its colour, that together describe the surfaces of a space. Drawings are made from it by cutting it with planes, horizontal for plans, vertical for sections and elevations, and drawing over the cut.

Space Read the guide

What size rug goes under a queen or king bed?

Choose a rug that reaches about 50–60 cm beyond each side of the bed, and start it just in front of the bedside tables. For a queen bed that usually means about 240 × 300 cm; for a king, about 270 × 360 cm, laid across the bed. A smaller rug works too when it sits under the lower two thirds of the bed and still shows on both sides.

What size rug do I need for a living room?

Size the rug to the seating group, not the room. The front legs of every sofa and chair should rest on it, which in most living rooms means 200 × 300 cm or 240 × 300 cm. Leave a band of floor between the rug and the walls, about 30–45 cm, so the room does not look carpeted wall to wall.

How high should I hang pictures?

Hang a picture or a group so its centre sits about 145–150 cm above the floor, roughly eye level for a standing adult. Above a sofa or sideboard, leave 15–25 cm between the furniture and the bottom of the frame, so the two read as one composition.

What is the best layout for a living room?

The best layout faces the seating towards one focal point, keeps people within about 2.5–3 m of each other so they can talk, and leaves the main path clear. Pull furniture off the walls when the room allows, place the coffee table about 40–45 cm from the sofa, and keep at least 90 cm for walkways.

How do I plan a furniture layout?

Measure the room, including doors, windows, radiators and sockets, and draw it to scale. Mark the paths people take between doors first, then place the largest piece, then everything else around it. Check every route is at least 90 cm wide and every seat has a surface within reach before you buy anything.

How high should I hang curtains?

Hang the rod 10–15 cm above the window frame, or halfway between the frame and the ceiling, which makes the window and the room look taller. Extend the rod 15–25 cm beyond each side so the open curtains frame the glass instead of covering it, and let the fabric just touch the floor.

How high should I mount a TV?

Put the centre of the screen at seated eye level, about 105–110 cm above the floor for most sofas. Mounting it higher, above a fireplace for example, makes people tilt their heads back; if you must, tilt the screen down towards the seats.

How far should the sofa be from the TV?

A comfortable distance is about 1.2 to 1.5 times the screen's diagonal for modern high-resolution screens. For a 140 cm diagonal, that is roughly 170–210 cm. Further is fine for casual viewing; closer feels immersive but tiring.

How wide should a hallway be?

Plan for at least 90 cm, which lets one person walk comfortably, and 110–120 cm where two people need to pass or furniture lines the wall. Wheelchair routes need about 120 cm, with turning space of 150 cm at the ends.

What size rug goes under a dining table?

The rug should reach at least 60–75 cm beyond the table on every side, so chairs stay on it when pulled out. For a table for six, that usually means about 240 × 300 cm. Match the rug's shape to the table: round under round, rectangular under rectangular.

Colour and materiality Read the guide

What colours go with green?

Green pairs naturally with the colours found next to it outdoors: warm whites, sand, terracotta, wood tones and soft pinks. Sage and olive greens suit cream, ochre and brass; deep greens suit navy, burgundy and gold. Keep one green dominant and repeat it, rather than mixing many.

What colours go with brown?

Brown works with creams and warm whites for a calm room, with blues (from sky to navy) for contrast, and with green, rust and mustard for warmth. Treat brown as a neutral: let wood and leather carry it, and add one stronger colour as an accent.

What colours go with grey?

First read its undertone. Warm greys suit cream, blush, ochre and wood; cool greys suit white, navy, black and blue-green. Grey also takes strong accents well, such as mustard, emerald or deep red, used in small amounts.

What colours go with navy blue?

Navy acts like a softer black. Pair it with warm white and natural wood for calm, with brass and camel for warmth, or with coral, rust or mustard for contrast. In small rooms, use it on one wall or on the joinery rather than everywhere.

What colours go with beige?

Beige suits other warm neutrals (cream, taupe, stone) layered in different textures, plus wood and black for definition. For colour, add sage, terracotta, dusty blue or olive. Avoid pairing it with cool, bright whites, which make it look dull.

How do I choose a paint colour?

Start from what stays in the room, such as the floor, the sofa or a rug, and choose a colour that works with it. Paint large samples, at least A3, on two walls and look at them in the morning, at noon and under lamps at night. Light changes colour more than anything else, so the same paint can look very different in a north-facing and a south-facing room.

What is a colour scheme?

A colour scheme is the planned set of colours a room uses and how much of each it shows. Common schemes are monochromatic (one hue in several values), analogous (neighbours on the colour wheel) and complementary (opposites). The 60-30-10 rule, about 60 percent dominant, 30 percent secondary and 10 percent accent, keeps any scheme balanced.

What is an undertone in paint?

An undertone is the subtle colour beneath a paint's main colour: a white may lean yellow, pink, blue or green. It shows most when you place samples side by side or against pure white paper. Matching undertones between walls, floor and furniture is what makes colours feel related.

How do I find my colour palette for a home?

Collect images of rooms you like and note which colours appear again and again, then check the colours you already own in clothes, art and objects. Build a palette of one dominant neutral, one or two secondary colours and one accent, and test them together on large samples in the actual room.

What colours go with purple?

Pale purples such as lilac suit soft greys, creams and sage green. Deep purples such as aubergine suit gold, mustard, olive and warm wood. Because purple is strong, use it in fabrics, art or one painted surface, and balance it with plenty of neutral.

Light Read the guide

How many lumens is a 60 W or 100 W bulb?

An old 60 W incandescent bulb gives about 800 lumens, and a 100 W bulb about 1,600 lumens. LED bulbs give the same light with far less power: about 8 to 10 W for 800 lumens. Compare bulbs by lumens, not watts.

What are lumens?

Lumens measure how much visible light a bulb gives out in total. The more lumens, the brighter the bulb. Lux measures how much of that light lands on a surface, which is what you actually see on a desk or worktop.

What is Kelvin in lighting?

Kelvin (K) describes a light's colour temperature: how warm or cool it looks. Around 2,700 K is warm and yellowish, like an old bulb; 3,000 K is warm white; 4,000 K is neutral; 5,000 K and above look cool and bluish, like daylight. Homes usually use 2,700 to 3,000 K in living spaces and bedrooms.

What colour light is best for sleep?

Warm, dim light is best in the evening: 2,700 K or lower, or amber and red light, which affect the body clock least. Avoid bright cool or blue-rich light in the hour or two before bed, and use dimmers or low lamps rather than ceiling lights.

How bright are 800 and 1,000 lumens?

800 lumens is the brightness of a classic 60 W bulb, enough for a table or reading lamp. 1,000 lumens is a little brighter, suited to a small room's main light or a desk. A living room usually needs several sources adding up to a few thousand lumens.

How many lumens does a room need?

Multiply the floor area in square metres by a target: about 100 to 150 lux for living rooms and bedrooms, 300 for kitchens and bathrooms, 500 for desks and worktops. A 20 m² living room at 150 lux needs about 3,000 lumens in total, spread across several lights rather than one.

How many recessed lights do I need?

As a rule of thumb, space recessed lights at about half the ceiling height: around 1.2 m apart for a 2.4 m ceiling, and about 60 cm from the walls. Use the lumens a room needs to check the count, and do not light the whole ceiling evenly: aim them at the places people use.

What is CRI in lighting?

CRI, the colour rendering index, says how faithfully a light shows colours compared with daylight, on a scale up to 100. Choose 90 or above for homes, so skin, food, wood and fabrics look natural. Cheap bulbs below 80 can make colours look flat or greenish.

What colour light bulb is best for a bathroom?

Use 3,000 K warm white for general light, so the room feels comfortable, and 3,000 to 4,000 K with a CRI of 90 or more at the mirror, where you need to see skin tones accurately. Light the face from both sides of the mirror to avoid shadows.

Is a flickering light bulb dangerous?

Flicker is often harmless: a loose bulb, an old fluorescent tube, or an LED that does not suit its dimmer. It can also signal a loose connection, which is a fire risk. Tighten or replace the bulb first; if several lights flicker, or one buzzes or smells hot, have an electrician check the circuit.

Acoustics Read the guide

How do I soundproof a room?

Soundproofing stops sound passing between spaces, and it relies on three things: mass, airtightness and separation. Seal gaps first, around doors, windows and sockets. Then add mass, such as an extra layer of dense plasterboard, and, where you can, separate the new layer from the old wall on resilient fixings with insulation in the gap. Soft furnishings reduce echo inside the room, but they do little to stop sound getting out.

How do I soundproof a door?

Most noise passes around a door, not through it. Fit seals around the frame and an automatic drop seal or a threshold at the bottom. A solid-core or acoustic door blocks far more sound than a hollow one.

How do I soundproof windows?

Seal the frame with acoustic sealant and replace worn gaskets. Laminated acoustic glass, or secondary glazing with a gap of 10 cm or more from the existing window, makes the biggest difference. Heavy, lined curtains help a little, mostly with higher pitches.

How do I soundproof a wall?

Add mass and decouple it: fix a second layer of dense or acoustic plasterboard on resilient bars or an independent frame, with mineral wool in the cavity. Seal every edge and box in the back of sockets, because small holes let a lot of sound through.

How do I block noise from outside?

Start with the windows and doors, the weakest parts of any wall: seal them, then upgrade to acoustic glazing or secondary glazing. Fill gaps around pipes and vents, fit acoustic trickle vents, and place bedrooms on the quieter side when you can plan the layout.

How do I soundproof an apartment as a renter?

Focus on what you can remove later: door seals, draught strips, heavy lined curtains, thick rugs with dense underlay, and bookcases full of books against shared walls. These reduce noise and echo noticeably, even though they cannot fully stop low-pitched sound.

How do I reduce echo in a room?

Echo comes from hard, parallel surfaces bouncing sound back and forth. Add soft, porous materials: a large rug, upholstered furniture, curtains, cushions, full bookshelves and acoustic panels. Spread them across different surfaces, including the ceiling in large rooms, rather than putting all of them on one wall.

Do acoustic panels work?

Yes, for echo inside a room: they absorb sound and shorten reverberation, so speech and music sound clearer. They do not soundproof, so they will not stop noise passing to the next room. Place them where sound first reflects, opposite or beside the people talking, and cover about 15 to 30 percent of the wall area.

How do I soundproof a ceiling from noisy neighbours?

Impact noise from footsteps is best stopped at its source, with a soft underlay or carpet upstairs. From below, add a new ceiling hung on resilient bars or acoustic hangers, with mineral wool above it and two layers of dense plasterboard, sealed at the edges.

How do I soundproof a floor?

Lay an acoustic underlay or a floating floor that sits on a resilient layer, so footsteps do not shake the structure. Rugs with dense felt pads help further. For airborne noise from below, add mineral wool between the joists and seal any gaps at the edges.

Temperature Read the guide

What is room temperature?

Room temperature usually means about 20–22 °C, the range most people find comfortable sitting still indoors in everyday clothes. Bedrooms feel better a little cooler, around 16–19 °C. What you feel also depends on the surfaces around you, draughts, humidity and clothing.

What should the humidity be in a house?

Aim for 40 to 60 percent relative humidity. Below about 30 percent, air feels dry and static builds up; above 60 percent, condensation, mould and dust mites become likely. In cold winters, 30 to 40 percent avoids condensation on windows.

How do I lower the humidity in a house?

Remove moisture where it is made: use extractor fans while cooking and bathing, dry clothes outside or in a vented dryer, and open windows briefly to air rooms. Keep rooms evenly heated, avoid blocking radiators, and use a dehumidifier in damp rooms or basements.

What should I set my thermostat to in winter?

About 20 °C when you are home and awake suits most people, with 16–18 °C overnight and when you are out. Each degree lower saves noticeable energy. Avoid turning it off completely in very cold weather, to protect pipes and prevent condensation.

What is radiant heat?

Radiant heat warms people and surfaces directly, without heating the air first, the way the sun warms your face on a cold day. Underfloor heating, radiant panels and warm walls work this way. It feels comfortable at a lower air temperature and avoids draughts.

How do I keep a house cool without air conditioning?

Block the sun before it reaches the glass, with external shades, awnings or shutters, and close curtains on sunny windows during the day. Open windows on opposite sides at night to let cool air through, use ceiling fans, and switch off heat sources such as lamps and appliances.

How do I increase the humidity in a house?

Use a humidifier in the rooms you spend most time in, dry laundry indoors on a rack, and add plants. Lowering the heating slightly also helps, because warmer air feels drier. Keep humidity below 60 percent to avoid condensation.

What is a smart thermostat?

A smart thermostat controls your heating or cooling from a phone app and learns your routine. It can lower the temperature when you leave, warm the house before you return, and control rooms separately. Most save energy by heating only when and where it is needed.

How do I keep a baby's room cool?

Keep the room at about 16–20 °C. Shade the window during the day, air the room in the cool evening, and use a fan to move air, never pointed directly at the baby. Dress the baby in light layers and use a room thermometer to check.

What causes high humidity in a house?

Everyday activities release moisture: cooking, showers, drying clothes and breathing. Poor ventilation keeps it inside, and cold surfaces make it condense. Leaks, rising damp and unvented appliances add more. Better extraction, steady heating and fixing water leaks bring it down.

Representation Read the guide

How do you read a floor plan?

Start with the scale and the north arrow, then follow the walls. Walls the cut passes through are the heaviest lines, filled or hatched; thinner lines are what lies below the cut, such as furniture and fittings, and dashed lines are what lies above it, such as beams, wall cupboards or a change in the ceiling. A gap in a wall with an arc is a door, the arc showing its swing; thin lines within a wall’s thickness are a window. Check whether dimensions run to wall faces or centre lines before measuring anything.

What is a floor plan?

A floor plan is a horizontal cut through a building, about 1.2 m above the floor, seen from above. It shows walls, doors and windows, fixed fittings and often furniture, drawn to scale, commonly 1:50 for a room and 1:100 for a whole home, so distances can be measured off it.

How do you draw a floor plan to scale?

Measure each wall, both diagonals to check the room is square, the position and width of every door and window, the ceiling height, and fixed items such as radiators, sockets and pipes. Pick a scale, 1:50 for a room or 1:100 for a home, draw the walls at their real thickness, then the openings with their door swings, then fittings and furniture. Finish with dimensions, room names and a north arrow.

How are stairs drawn on a floor plan?

Draw each tread as a line across the flight, with an arrow from the bottom step marked UP. The plan’s cut, about 1.2 m above the floor, slices through the flight: mark it with a diagonal break line, and draw the part above it dashed or leave it out. On the floor above, the whole flight lies below the cut and is drawn in full, its arrow marked DN.

What is the difference between a section and an elevation?

A section cuts through the building and shows what the cut passes through, walls, floors and ceilings drawn heaviest, plus what lies beyond. An elevation is a flat, straight-on view of one face with nothing cut, such as one wall of a room with its windows, joinery and finishes. Interiors need an elevation of every wall with something to build on it: a kitchen, joinery or tiling.

What is an isometric drawing?

An isometric is a 3D drawing whose three axes sit 120° apart on the page and share one scale, so lengths along any of them can be measured. It is one kind of axonometric: dimetric drawings shorten one axis, and a plan oblique keeps the plan true and lifts its verticals straight up. None of them has vanishing points; parallel lines stay parallel.

What is a vanishing point?

A vanishing point is where lines that are parallel in reality appear to meet in a perspective drawing. Each set of horizontal parallels meets at its own point on the horizon, and the horizon always sits at the viewer’s eye height. Lines parallel to the picture, such as the verticals in a level view, never converge.

What is the difference between one-point and two-point perspective?

In one-point perspective you face a wall square-on: the lines running away from you meet at a single vanishing point, while the lines across the view stay level. It suits a view down a room or a corridor. In two-point perspective you look into a corner: each wall runs to its own vanishing point on the horizon, the verticals stay vertical, and the room reads more naturally in depth.

What is a bubble diagram?

A bubble diagram is a quick sketch of a plan’s spaces as loose circles, each sized roughly by its area, with lines joining the ones that must connect. It settles relationships, what sits next to what, what needs direct access and what needs privacy, before any wall is drawn. Several are tried, and the best becomes the first plan.

What is a 3D rendering in interior design?

A rendering is an image computed from a 3D model of the room, with its materials and lights, seen through a virtual camera. It shows the client how the finished room will look and feel before anything is built, and is used to approve materials, colour and light. It is a presentation tool, not a construction drawing: the plans, sections and schedules are what get built.

Styles Read the guide

What is my interior design style, and how do I find it?

Collect twenty or thirty images of rooms you love, without judging them, then look for what repeats. Note the shapes (curved or straight), the palette (warm or cool, quiet or bold), the materials (timber, metal, stone, textiles) and how full or empty the rooms are. Those repeats are your style, described through its ingredients rather than a label. Test it on one room, and keep what still feels right a few weeks later.

How do I style furniture in a room?

Start with one anchor, usually the sofa or the bed, and face it towards the focal point: a window, a fireplace or a view. Float furniture off the walls into conversation groups about 2.5–3 m across, and keep 90 cm clear for the main paths. Ground each group with a rug large enough for the front legs of every seat. Then layer: lighting at three heights, a few objects grouped in odd numbers, and empty space so the eye can rest.

How do I mix furniture styles?

Let one style lead, at roughly 80 percent, and let the others accent it. Link the pieces through something they share: a repeated colour, a material, a line or a scale. Mix across periods rather than within them, such as an antique table with modern chairs, and repeat each newcomer at least twice so it reads as intended. Keep the palette tight when the shapes vary, and vary the shapes when the palette is tight.

What is Art Deco interior style?

Art Deco is the glamorous style of the 1920s and 1930s. It combines bold geometry (stepped forms, chevrons, sunbursts and fans) with luxurious, contrasting materials: lacquer, polished brass and chrome, marble, mirror and rare veneers. Rooms are often symmetrical, with strong colours such as emerald, black and gold, curved upholstered furniture and dramatic lighting.

What is Zen interior design?

Zen interior design draws on Japanese and Buddhist ideas of calm and simplicity. It uses few objects, low furniture, natural materials such as wood, bamboo, stone, paper and linen, and a soft palette of earth tones. Clear surfaces, diffused natural light and a strong connection to nature, through plants, views or water, matter more than decoration.

What is shabby chic?

Shabby chic is a soft, romantic style built on furniture that looks old and loved: painted wood with worn edges, chipped finishes and vintage pieces. It pairs whites and pale pastels with faded florals, linen, lace and slipcovered sofas. The aim is comfort that looks collected over time, never brand new.

What is mid-century modern style, and is it still in style?

Mid-century modern covers design from about the 1940s to the 1960s: low furniture on slim tapered legs, organic curves, teak and walnut, moulded plywood and fibreglass, and clean lines with little ornament. It has stayed popular for decades because it is human in scale, practical and easy to mix with other styles. Today it is used more as an accent than as a full period room.

What is transitional interior design?

Transitional design sits between traditional and contemporary. It keeps the comfort and classic proportions of traditional furniture, but strips back the ornament and uses a calm, neutral palette with texture for interest. Think a rolled-arm sofa in plain linen beside a simple metal lamp. It suits people who want warmth without fuss.

What is eclectic design style?

Eclectic style deliberately combines pieces from different periods, cultures and styles in one room. It works when something holds the mix together: a limited palette, a repeated material or shape, and a clear sense of scale and balance. Without that thread it reads as clutter; with it, the room feels personal and collected over time.

How many interior design styles are there?

There is no fixed number: lists range from about ten to more than forty, because styles overlap and new names appear all the time. A more useful approach is to learn the ingredients every style is built from (scale, proportion, balance, rhythm, materials and mood). With those, you can read any style, name or no name, and the thirteen historical styles above cover the main sources most modern styles borrow from.

Use Read the guide

How do you decorate an open floor plan?

Treat it as several rooms that share one space. Give each zone an anchor, such as a rug under the seating, a pendant over the table or a run of cabinets, and turn the furniture to face into its own zone. Keep the main route between zones clear, and repeat one or two colours or materials across the whole space so the zones still read as one.

How do you separate spaces in an open floor plan without walls?

Use furniture, light and floor finishes rather than partitions. A sofa back, a shelving unit or a kitchen island marks an edge while keeping the view open. A change of rug, ceiling height or lighting level tells people they have entered a different area. Where noise or privacy matters, a glazed screen or a sliding panel separates the activity without losing the light.

What is space planning in interior design?

Space planning is working out how a space will be used before choosing finishes: which activities go where, how much room each needs, what sits next to what and how people move between them. It runs from the program through zoning and adjacency to a furnished layout, tested against real furniture sizes and clearances.

What is architectural programming?

Programming follows the brief and survey, at the start of a project. It turns the brief into a list of spaces, with the activities, users, sizes and relationships each one needs, plus the budget and timescale that frame them. The result, often called the program or space schedule, is the yardstick every later design option is judged against.

What is a bubble diagram in architecture?

A bubble diagram is a quick sketch of a plan in which each space is a loose circle, sized roughly by its area, with lines joining the spaces that must connect. It lets you test arrangements before committing to walls. Sketch several, keep the strongest links short, then check the best ones against windows, entrances and structure.

What is an adjacency matrix in interior design?

An adjacency matrix is a grid that lists every space along the top and down the side, and marks each pair by how close they need to be: directly connected, nearby or kept apart. It records the relationships from the brief in one place, so nothing is forgotten when you move on to bubble diagrams and plans.

How much space should you leave between furniture for walking?

Allow about 90 cm for a main route through a room and about 60 cm for a secondary path, such as behind a chair or beside a bed. Leave 75 to 90 cm behind a dining chair so someone can stand up and others can pass. Test the layout with chairs pulled out and doors open, not just on an empty plan.

What is the standard width of a hallway?

In homes, hallways are usually 90 to 110 cm wide, and building codes typically set a minimum of around 90 cm. Where a wheelchair needs to pass or turn, plan for 120 cm or more, and check the accessibility rules that apply where you are building.

What is a flexible space?

A flexible space is a room designed to change use without building work, such as a study that becomes a guest room or an office floor that switches between desks and meetings. It needs fixed services in the right places, furniture that is light enough to move, and somewhere to store what each layout does not use.

How do you transition paint colours in an open floor plan?

Change colour where the architecture gives you an edge: an inside corner, a doorway, a column or a change in ceiling height, never in the middle of a flat wall. Keep the colours related by undertone, or keep one colour on the trim and ceiling throughout, so the space still reads as one.

Codes and rules Read the guide

What is a certificate of occupancy?

It is the document the local building department issues to confirm that a building, or a space within it, complies with the codes and can be occupied for its intended use. It is usually needed after new construction, after a major renovation and whenever the use changes, for example when an office becomes a restaurant. Without it, a tenant may not be allowed to open.

What is a building permit, and does an interior project need one?

A building permit is permission from the local building department to carry out specific work, followed by inspections. Interior projects usually need one when they move or remove walls, alter the structure, change the layout of rooms or exits, or add or alter electrical, plumbing, gas or ventilation work. Painting, new flooring and like-for-like cabinet replacements often do not. The rules vary by place, so check with the local department before the design is fixed.

What does ADA compliant mean?

It means a space meets the 2010 ADA Standards for Accessible Design, the technical rules under the Americans with Disabilities Act. They apply to public accommodations, commercial facilities and state and local government buildings in the United States, including shops, restaurants, offices and hotels. Private homes are generally not covered, although state and local codes may add their own requirements.

What are the requirements for an ADA-compliant bathroom?

Under the 2010 ADA Standards, a single-user toilet room needs a 60 inch turning circle or a T-shaped turning space, a door with at least 32 inches of clear width, a toilet centred 16 to 18 inches from the side wall, grab bars on the side and rear walls mounted 33 to 36 inches above the floor, a sink no higher than 34 inches with knee space below, and a mirror whose reflecting surface starts no higher than 40 inches. Controls must work with one hand, without tight grasping or twisting.

What is the maximum slope of an ADA ramp?

The 2010 ADA Standards allow a running slope of no more than 1:12, which is one inch of rise for every 12 inches of run. Each run may rise at most 30 inches before a level landing, the cross slope may not exceed 1:48, and a ramp that rises more than 6 inches needs handrails on both sides. A gentler slope is easier for everyone.

What is the ADA counter height?

Sales and service counters need a section at least 36 inches long and no higher than 36 inches above the floor, so a wheelchair user can approach and be served. Work surfaces and dining surfaces for public use should be 28 to 34 inches high, with knee clearance below.

What is the minimum ADA door width?

A door must give at least 32 inches of clear width, measured with the door open at 90 degrees between the face of the door and the opposite stop. Thresholds may be no higher than half an inch, bevelled, and the door needs clear manoeuvring space on both sides and hardware that works without tight grasping.

What is an egress window?

An egress window is a window large enough for people to escape through and for firefighters to enter. In the United States, the International Residential Code requires one in every sleeping room and in habitable basements, with a net clear opening of at least 5.7 square feet, at least 24 inches high and 20 inches wide, and a sill no more than 44 inches above the floor. A basement bedroom without one cannot legally be called a bedroom.

What is the standard height of a handrail?

Both the International Residential Code and the International Building Code set stair handrails at 34 to 38 inches above the stair nosings. In England, Approved Document K sets 900 to 1000 mm. Handrails must be continuous and easy to grip, and accessible routes often need one on each side.

What is the building code for stairs?

Under the International Residential Code, a stair in a home may have risers of at most 7¾ inches and treads of at least 10 inches, with at least 6 feet 8 inches of headroom. The International Building Code is stricter for other buildings: risers of 4 to 7 inches and treads of at least 11 inches. Keep every riser and tread in a flight the same size: uneven steps cause falls.

What is a fire-rated door?

A fire-rated door is a complete door assembly, including the leaf, frame, hinges, closer, seals and any glazing, that has been tested to hold back fire for a set time, such as 20, 60 or 90 minutes. It carries a label, must close and latch on its own, and only performs as tested when installed as tested. Changing any part, from the hinges to a vision panel, can void the rating.

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