The interior design guide
Open Rayon

The interior design guide. A definitive knowledge base for interior designers.

From first principles to the finishing touches: shell, surfaces, space planning, furniture, electrics, plumbing and joinery, in the order a project runs.

Get startedKnowledge base

The Lexicon.

Every term, in plain words.

From hue and light reflectance to bonding and kick space, every term the guide uses has a short definition, what to know in practice and the pages that use it.

Open the Lexicon

Use the guide in your AI assistant.

Connect Claude or ChatGPT.

The guide has an MCP server, so your assistant can search it, read its pages and cite them while it answers you. It is free, read-only, and needs no account or key.

Connect to Claude
Open docs
All sections

The interior design guide.

A definitive knowledge base for interior designers.

Eleven chapters take a home from first principles to the moment you show it to the client. Start with Foundations and read in order, or search for a topic, a term or a rule of thumb.

Chapters.

Eleven steps, from principles to presentation.

Keep reading.

Where to go next.

Sections.

Keep reading.

Where to go next.

Lighting scene.

What it means in interior design.

A lighting scene is a preset combination of circuits and dim levels, recalled with one switch or button. Typical living-room scenes are day, evening and late.

In practice

Clients use scenes; they ignore a wall of individual dimmers. Even without a smart system, putting all the lamps on one switched socket circuit gives a basic evening scene.

Where the guide uses it

  • Defined here, in the Lexicon.

Related terms.

More from Electricals.

First fix

First fix is the stage when cables, pipes and back boxes go in, before walls are plastered and floors finished. After it, moving a socket or light point means cutting into finished surfaces.

Layered lighting

Layered lighting combines ambient, task and accent light from several sources at different heights. Each layer is switched or dimmed on its own so the room can change mood.

Ambient light

Ambient light is the general background light that lets people move around safely. It sets a room’s overall brightness but rarely its character.

Task light

Task light is focused light for a specific activity: reading, cooking, working. It is brighter than ambient light and aimed at the work surface.

Accent light

Accent light is directional light that picks out an object or surface: art, texture, a plant. It works by contrast, so its surroundings must be dimmer.

Wall washing

Wall washing lights a wall evenly from fittings set back from it, usually in the ceiling. Because we judge brightness by vertical surfaces, a washed wall makes the whole room feel brighter and larger.

Colour temperature

Colour temperature describes how warm or cool white light looks, in kelvin (K). Lower is warmer: a warm home bulb is about 2700 K, daylight roughly 5000–6500 K.

CRI

CRI (colour rendering index) measures how faithfully a light shows colours compared with a reference light, on a scale up to 100. Low-CRI light makes wood, fabric and skin look dull or grey.

Lux

Lux measures how much light falls on a surface, in lumens per square metre. It is what a light meter reads, and different tasks need different levels.

Back to the Lexicon

Units