Rules, Ratios And When To Break Them: 70/30, 60/40 And The Golden Touch.
Every design rule starts with a useful truth, then meets a real room. Walls shift, light changes, heirlooms insist on being seen. Ratios help you find balance in the midst of all that character. They are guides, not shackles.
At Shanade McAllister Fisher Design in London, proportion sits at the centre of each composition. Ratios shape palette, furniture scale and the rhythm of joinery, yet are applied with judgement. Materials and light make the final call. The outcome is calm, character driven spaces that feel inevitable, not formulaic.
This primer walks through popular interior ratios, how we use them, and where we bend them to express personality. You will also find simple word sketches to test ideas at home without a tape measure or mood board marathon.
Why ratios matter in real rooms
Ratios simplify complex choices. They allocate emphasis so a space has a clear lead and supportive chorus. In practice, that means one colour or material reads first, others harmonise, and contrast arrives with intent. Ratios also help furniture scales talk to the architecture, so a sofa weight, a dining table diameter and a pendant drop feel connected.
In West London homes with generous daylight, we may let a lighter ground carry 70 percent of the visual field, allowing darker joinery to punctuate. In compact city apartments, reflective planes and softly sheened finishes can borrow light, so a 60/40 balance of tone might be enough to create depth without noise. Ratios become a language for restraint.
The 70/30 rule explained
The 70/30 rule suggests around 70 percent of a room should be one dominant palette or mood, with 30 percent acting as a contrasting partner. Think of it as base and counterpoint.
A quiet example: pale oak flooring, chalk soft walls and linen window dressings make up the 70. Brushed brass details, a tobacco leather chair and a graphite console form the 30. The room breathes, yet has definition. In joinery, this might read as cabinetry that gently recedes over most elevations, with one bank expressed as a sculptural moment, perhaps with metal inlays or a richer timber.
Try this at home: gather fabric swatches or objects on a table. Aim for seven pieces in one family (similar tone, texture or hue), three with deeper contrast. Step back. If the minority reads as punctuation rather than takeover, you are close to 70/30.
The 60/40 rule, and when it helps
The 60/40 rule often governs tonal balance, not colour count. It proposes a near equal conversation where one side still leads. Useful in through spaces or open plan rooms that must bridge two moods, it stops a scheme feeling split in half.
Imagine a living dining space in London with internal glazing: 60 percent warm neutrals across walls and large upholstery, 40 percent cooler stone and charcoal in the dining zone. A shared timber tone across both areas stitches the narrative so movement feels fluid, not binary.
Home test: fold a blanket over a sofa so roughly three fifths is one shade and two fifths another. Place two cushions that echo each part. Does the room feel coherent as you move? If yes, 60/40 is doing the quiet work.
The 3 5 7 rule, and the power of odd groupings
The 3 5 7 rule champions odd numbers for styling and rhythm. Three objects create a dialogue, five a small landscape, seven a layered vignette. Heights should step and textures should vary so the eye travels.
On a console, try three: a framed artwork leaning, a ceramic vessel, a small stack of books. For five on shelving, add a low bowl and a sculptural object in a contrasting material. The aim is cadence, not clutter. In joinery, 5 or 7 can set door panel rhythms across a wall, aligning with architectural lines to feel intentional rather than decorative.
Home test: place three items of different heights on a mantel. Step them like a skyline, tallest at one side, medium central, smallest forward. If it feels static, swap positions until a gentle zigzag of sight emerges.
The golden ratio in interiors
The Golden Ratio, often expressed as 1:1.618, describes proportions that feel naturally balanced. In interiors, it guides relationships: sofa length to coffee table, island size to kitchen run, artwork cluster to wall expanse.
Examples:
A 160 cm sofa pairs comfortably with a coffee table near 100 cm in length, leaving air to circulate.
Bookshelf bays might follow the ratio in height to width so uprights feel calm rather than crowded.
In lighting, the drop of a pendant over a dining table can echo the table width ratio so volume feels poised.
Treat 1:1.618 as a compass, not a demand. Architecture and movement patterns may nudge it to 1:1.5 or 1:1.7 and the room will still sing.
Proportion, contrast and balance in palettes and joinery
Proportion gives hierarchy, contrast brings character, balance keeps the peace. In a Tufnell Park family home, calm walls and hand finished oak set the majority field. Brushed brass and sculptural lighting deliver contrast in measured doses. Concealed storage keeps rhythm unbroken, while one expressive cabinet face becomes the memorable note.
In kitchens as furniture, we often let door rhythms follow architectural cues: window mullions, floorboard widths, sightlines. Ratios then calibrate finish distribution. Gloss lacquered planes appear sparingly to lift light; honed stone anchors surfaces; warm woods keep touch central. The eye reads a composed score rather than individual instruments.
Simple word visuals to test at home
The paper window: cut a rectangle from white paper. Colour roughly 70 percent with a pale pencil, 30 percent with a darker tone. Hold it up to your room like a viewfinder and imagine walls and key furniture following that split.
The string grid: tape a cotton string across a shelf span, dividing it into 5 equal sections. Place objects so 3 sections hold mass and 2 hold air. Adjust until the empty space feels purposeful.
The floor map: on the floor, lay two blankets overlapping. One covers about 60 percent of the footprint, the other 40 percent. Position a coffee table where both meet. You will feel the zone boundary soften.
When to bend or break the rule
Rules protect clarity until personality arrives. An heirloom rug may claim more than 30 percent of attention. A gallery wall might exceed 7 pieces because the story warrants it. In commercial spaces, brand colour can ethically overrule 60/40 to create impact at arrival, while back of house zones retreat into neutrals for focus.
Our studio often inverts the expected: a dark majority palette in a north facing room, balanced by reflective detailing and soft ambient lighting to borrow light without glare. Or ultra quiet cabinetry across 90 percent of a wall, interrupted by a single metal inlaid bay that frames ritual. The question is always the same, does the space feel honest and intentional.
If you are exploring a London home or workspace and want a considered partner, you can learn more about our interior design services in London on our site. We also share how character led narratives translate into zoning and atmosphere in our Soho case study on commercial interior design.
Is four colours in a room too much?
It depends on proportion and family. Four colours can feel effortless if one leads, two support, and one accents. Keep undertones aligned, repeat each shade at least twice, and vary texture so the palette layers rather than shouts. Think linen oatmeal as the base, soft clay and pewter as supports, petrol blue as a precise accent.
Quick FAQ
What is the 70/30 rule in interior design? A guiding split where around 70 percent of the scheme is a dominant palette or mood, with 30 percent offering contrast to create focus and depth.
What is the 60/40 rule in interior design? A near even tonal balance used to bridge adjacent zones or moods, ensuring coherence without monotony.
What is the 3 5 7 rule in interior design? A principle of odd number groupings for styling and rhythm, from three object vignettes to seven part arrangements or panel rhythms.
What is the Golden Ratio in interiors? A proportion of roughly 1:1.618 used to relate sizes of elements, from furniture to joinery, for a naturally balanced reading.
Is four colours in a room too much? Not if proportions are controlled. One lead, two supports, one accent is a reliable approach.
Bringing your story into the ratios
Ratios create clarity so stories can take root. Bring your collections, art and family pieces into the conversation; let them guide where a rule flexes. In London apartments, townhouses and commercial spaces across England, we compose interiors as narratives, fusing Interior Design and Interior Architecture with craft and restraint. If you would like a private consultation in West London or across the capital, explore our services and portfolio. Clients searching for trusted interior designers in London can review our approach in detail, and those seeking recent feedback may find reassurance in our interior design testimonials from past commissions.