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.

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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.

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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.

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Where to go next.

Sections.

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Where to go next.

Surface documentation,

from material choice to buildable instruction.

Once finishes are chosen and their layouts resolved, the designer must say where each material goes, how it is installed and which product it is. Finish plans locate materials, elevations explain vertical coverage, details resolve junctions and schedules collect the specifications; a finish code ties them all to one material.

The finish plan.

Materials, located.

A finish plan is a floor plan given over to surface materials. It leaves out most of what a general plan shows and concentrates on where each finish goes, where it stops, and what it is: timber in the living areas, tile in the bathroom, a resilient floor in the service rooms, each with its code and, where it matters, an arrow for the laying direction. At every change of material it fixes the exact extent of each finish and refers to the detail that builds the junction.

The walls are cut at 0.9 m so every floor reads, and their faces carry the wall finishes. Boards are drawn with their end joints and arrows give the laying direction; double lines at the doors mark the transitions.

Finish codes.

One code, one material, everywhere.

A finish code identifies a product without repeating its specification on every drawing. A simple convention separates floors, walls and ceilings. These codes are an example, not a standard: offices use their own prefixes and numbering. Once adopted, a code stays the same across drawings, schedules, specifications and revisions, and never names two products in one project.

CodeDescription
F-01Engineered oak flooring
F-02Porcelain floor tile
F-03Resilient sheet flooring
W-01Matt painted plaster
W-02Ceramic wall tile
W-03Decorative timber panelling
C-01Painted plasterboard ceiling
C-02Acoustic ceiling panels
Choose a code, a room or a schedule row: the same finish lights up in the plan, the elevation and the schedule.

Representing materials in drawings.

Line weights, hatches, legends.

Drawings separate surfaces with line weights, hatches, symbols and notes. A hatch may suggest timber, stone or tile, but state its meaning in a legend wherever it could be misread: projects and drafting standards differ. Line weights set the hierarchy between boundaries, finish patterns, dimensions and background construction, and notes must stay legible at the printed scale. Above all, be consistent, and never rely on colour alone.

Dimensioning finish plans.

Locate the boundaries, not the building.

A finish plan needs no repeat of every building dimension. Its dimensions locate finish boundaries, patterns, transitions and special features: where a material changes relative to a wall or opening, the extent of a tiled area, the centreline of a pattern. Measure from fixed architecture, never from movable furniture, and avoid chains and duplicates that drift apart in revisions.

Wall finish elevations.

What a plan cannot show.

Elevations show the vertical extent of finishes: tile, panelling, bands, splashbacks and changes of paint or wallcovering. A bathroom elevation sets where tiling starts and stops, whether it runs behind fixtures, and how it meets the ceiling, doors, niches and exposed edges. Give heights from a defined finished floor level, with notes or details where tolerances affect the result.

A bathroom wall, its heights from the finished floor and its finish codes; the key plan shows which wall.

Reflected ceiling finish plans.

The ceiling, seen from below.

Ceiling finishes are usually set out on a reflected ceiling plan, together with lighting and other ceiling equipment. Where the ceiling changes material or level, the plan shows the extent of each; suspended acoustic systems may also need their grid, access panels and coordination with services. Never specify a ceiling apart from its acoustics, lighting, ventilation and maintenance access.

The finish schedule.

Every finish, in one place.

The finish schedule gathers material information so it can be reviewed, priced, ordered and installed: each code, its manufacturer or source, product, colour, size, surface treatment, location and remarks. For construction it may add performance criteria, substrate requirements, installation method, approved alternatives, maintenance and references to the specification. The example is illustrative: a project schedule must be precise enough to order from without ambiguity.

CodeSurfaceMaterialFinish / colourLocationNotes
F-01FloorEngineered oakNatural, mattLiving, bedroomsLaying direction per plan
F-02FloorPorcelain tileWarm greyBathroomWet-area suitability to be confirmed
W-01WallInterior paintOff-white, mattLiving, bedroomsPrepare substrate
W-02WallCeramic tileWhite, satinBathroomExtent per elevations
C-01CeilingInterior paintWhite, mattGeneralCoordinate substrate and lighting

On projects with many rooms, a room schedule sits beside the material schedule. The room schedule answers where each finish is used; the material schedule, what each finish is. They serve different purposes and must agree.

RoomFloorWallsCeilingSkirting
Living roomF-01W-01C-01S-01
BedroomF-01W-01C-01S-01
KitchenF-01W-01 / W-02C-01S-01
BathroomF-02W-02C-01S-02

Detailing critical junctions.

Enlarged where it matters.

Not every interface needs a detail, but junctions with unusual thicknesses, movement, waterproofing, exposed edges or high visibility often do: tile-to-timber thresholds, skirtings, wall tile terminations, shower transitions, recessed ceiling edges. A detail names the adjacent materials, the build-up, the fixing or bonding where specified, the critical dimensions and the interfaces other trades must coordinate.

1 · Tile to timber, flush: F-02 meets F-01.
2 · Skirting: S-01 over the floor’s expansion gap.
3 · Wall tile termination: W-02 stops, W-01 continues.
4 · Ceiling shadow gap: C-01 stops short of the wall.

Coordinating and reviewing.

Before the package goes out.

Check the finish drawings against the plans, elevations, services drawings and specifications. A floor transition must not clash with a door threshold; a tile pattern must allow for plumbing fixtures and openings; a suspended ceiling must take lights, detectors, ventilation outlets and access panels. Schedules often feed quantity take-offs, but allowances for cutting, waste, spares and pack sizes depend on each material and layout. Before issue, check that codes are unique, legends complete, extents unambiguous and revisions carried through everywhere.

Checklist.

Before you issue the drawings.

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Surface documentation

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Where to go next.

Previous

Surface layout and transitions

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4 · Space planning

Units