Guides · Light · 13 min read · Updated September 2026

Lighting

The tradition has more to say about light than about anything else in a room, because light is what yin and yang look like indoors. Where the lamps go and at what height, what colour the light should be and when, the window as the first lamp, the three layers a designer works in, the numbers the research gives for the evening, and a room-by-room list.

Oriented S 171°

Fire

Fig. 01 Sunlight across a plaster wall. The tradition’s first lamp is the window, and every other light is placed in relation to it.

Light is the tradition’s working material. Yang is the lit side of the hill and yin the shaded, and a room is read by where its light falls and where it does not. The rules that follow are few, and most of them coincide with what a lighting designer would draw: light where people are, dark where they rest, warm at night, cool by day, and nothing glaring at the height of an eye. What the tradition did not have, and this page adds, is the heights, the numbers and the layers.

The window first

The tradition’s first lamp is the window, and its first question about a room is where the daylight comes from and when. An east window lights the morning and is dark by afternoon; a south window, in the northern hemisphere, lights the whole day and burns at noon; a west window is dim until the afternoon and then floods; a north window is even, cool and shadowless from dawn to dusk. The direction pages draw the sun’s path for each, and the windows guide gives the room two ends. Everything below is placed in relation to that window: the desk to its side, the table where its light still reaches, the lamps where it never does.

Where the light goes

Plan 01 Light in a living room: pools of light where people are, and none in the middle of the ceiling Daylight falls off from the window on the right. The lamps are placed where the tradition wants light: over the table, beside the main seat, in the corner that daylight never reaches, and at the door where a person arrives. The ghosted single ceiling light in the middle of the room is the fitting most rooms are handed and the one that lights nothing in particular.

The plan above is a living room lit the tradition’s way. Daylight comes from the window and falls off across the room, so the table sits where it still reaches. A pendant hangs low over the table for the evening. A lamp stands beside the main seat, at the height of a book. A lamp stands in the corner the window never lights. A light at the door greets whoever comes in. The ceiling light in the middle is drawn as a ghost, because it is the one that can be left off.

Heights

The tradition places lamps by where people are and does not give heights; the designer does, and they are worth having because a lamp at the wrong height is a lamp in the eye.

Over a table. The bottom of the shade about seventy-five centimetres above the surface: low enough to light the food and the faces, high enough not to meet a standing guest. This is the one pendant the tradition asks for.
Beside a seat. The bottom of the shade level with, or just below, the eye of the person sitting, about a metre from the floor, so that the bulb is hidden and the light falls on the lap and the book.
Beside a bed. Lower again: the shade at the height of a lying eye, sixty to seventy centimetres, and the switch within reach of a lying hand.
In a corner. A floor lamp with its shade at about a metre and a half, at the height of a standing eye and above a seated one, so that it lights the corner rather than the room.
At the door. High enough to light the floor and the faces of those arriving, on a switch by the door and, at night, on a timer.

A bare bulb at the height of an eye, on a wall or in a low pendant, is the tradition’s sha of light: a point aimed at a person. Shade it, raise it or lower it.

Fig. 02 The five lamps of the tradition’s room at the heights the designer gives, drawn in section against the three eye lines: a lying eye at about sixty-five centimetres, a seated eye at about a hundred and fifteen, a standing eye at about a hundred and sixty. The rule under all five is one rule: the bottom of the shade at or just below the eye of the person the lamp is for, so that the bulb is hidden and the light falls on the lap, the page, the food and the faces and not into anyone’s eyes. The pendant over the table hangs with its shade seventy-five centimetres above the top, which is below a standing guest’s eye and above a seated one’s; the lamp beside a seat has its shade at the seated eye; the lamp beside a bed is lower again, at the lying eye, with the switch within reach of a lying hand; the floor lamp in a corner has its shade at a hundred and fifty, above the seated eye and below the standing one, so that it lights the corner and not the room; and the light at the door is high, to light the floor and the faces of those arriving. A bare bulb at the height of any of the three eyes is the tradition’s sha of light, a point aimed at a person. The heights are the ones interior designers use and Boyce 2014 gives the reasons for, the eye’s sensitivity to a bright point in a dim field and the loss of contrast with age. The tradition places lamps by where people are and never gave heights; these are the heights its placings imply.

The drawing puts the five on one section against the three eye lines, and the list above collapses to a rule: the bottom of the shade at or just below the eye of the person the lamp is for. A lying eye is at about sixty-five centimetres, a seated one at about a hundred and fifteen, a standing one at about a hundred and sixty, and every lamp in the room is placed by one of the three. The reason is the one Boyce’s text gives, that the eye adapts to the average of the field and a bright point in a dim field is glare whatever its wattage, and that an older eye, which needs two or three times the light for the same page, is also the one most troubled by the point; the tradition’s sha of light and the lighting engineer’s glare index are the same complaint.

Warm and cool

Fig. 03 Colour temperature, from a candle to an overcast sky, drawn as the tradition reads the day: the warm, dim end is yin and belongs to the evening and the bedroom, the cool, bright end is yang and belongs to the morning and the desk. Bulbs are sold by this number. Below about 2700 kelvin, dimmed, is what the sleep research allows in a bedroom after dusk; 4000 and above is daylight’s territory and belongs where work is done, in the daytime. The tradition’s Fire and Water, warm and cool, sit at the two ends.

The tradition’s two temperatures are Fire and Water: the warm, red-yellow light of flame and evening, and the cool, blue-white light of water and the morning sky. It wants Fire at night and Water by day, which is also what the bulbs now say on the box. Warm light, at 2700 kelvin and below, is the evening’s; cool light, 4000 and above, is daylight’s, and belongs where work is done while it is day. A candle, at about 1900 kelvin, is the tradition’s ideal evening light and its element is Fire; a kitchen at noon can be Water. A house with one colour of light everywhere, which is most houses, has no evening in it.

Evidence · Light at night, with numbers

Gooley and colleagues found that ordinary room light in the hours before bed, at levels below two hundred lux, the brightness of a well-lit living room, suppressed melatonin and shortened its duration compared with dim light; Chang and colleagues found a lit screen in the evening delaying sleep and dulling the next morning, and Cajochen’s group found the same with blue-rich screen light. The effect depends on brightness and on the blue end of the spectrum, which is why dim and warm is the combination the research allows after dusk: a few lamps at a few tens of lux, at 2700 kelvin or below. Office workers with windows slept longer than those without (Boubekri and colleagues), and in a year-long study across four countries mood tracked the light and was lowest where the lighting was felt to be too dark (Küller and colleagues). Bright and cool by day, dim and warm by night, is the tradition’s day and the evidence’s.

The practical version is two circuits, or two habits: the bright cool light of the working day, from the window and the task lamps, and the dim warm light of the evening, from the lamps beside the seats and over the table, with the ceiling off. A dimmer on the one ceiling fitting that cannot be avoided, and warm bulbs in every lamp that is used after dark, does most of it. Harding’s account of the body cooling toward sleep adds one more thing: the warm light of the evening should be a low light, because a bright warm room is still a bright room.

Room by room

Entrance. Bright and warm, on a switch reachable from the door and on a timer after dark; the tradition wants the house to receive whoever comes in with light, and a mirror on the side wall doubles the one lamp.
Living room. Lamps at sitting height, a pendant over the table, a lit corner, and the ceiling light off; dimmers if the room does more than one thing.
Dining. One warm light hung low over the table’s centre, seventy-five centimetres above it, and nothing else on while the meal lasts.
Kitchen. Cool task light on the counters where the work is, under the wall cupboards, placed so that the cook does not work in their own shadow; warm light over the table if there is one, and the two on separate switches.
Bedroom. No ceiling light on after dusk; lamps at the bedside, low and warm, with the switch within reach; a blind or curtain that makes the room dark; a night light at skirting height for the path to the door; the better sleep guide has the rest.
Bathroom. Light at the sides of the mirror, not above it, which the tradition reads as a face in shadow and the designer as unflattering; a low second light for the night.
Home office. Daylight from the side, a task lamp on the side opposite the writing hand, and the screen never the brightest thing in the room; the home office page draws the three desks.
Halls and stairs. Lit at the end and at the turn, so that the eye has somewhere to go, which the hallways page draws.
Outside the door. A lamp over or beside the door that lights the step and the number, on all night or on a sensor; the first thing the tradition asks of a front door is that it be found.

Checklist

The window read first: which way it faces, and when its light comes
The entrance lit at night, on a switch by the door
Lamps where people sit and eat, not one light in the middle of the ceiling
The dark corner given a lamp
Nothing hung low over a bed or a seat; the pendant over the table at seventy-five centimetres
Shades at the height of the eye they serve: seated beside the sofa, lying beside the bed
Warm and dim after dusk, cool and bright by day; two circuits or two habits
Bedroom dark at night, lamps at the bedside only
No bare bulb at eye height