# Representation: how interiors are drawn > How interiors are drawn: plan, section and elevation and their cut, seen and hidden lines, axonometric views, diagrams, perspective and rendering. Source: https://guide.rayon.design/knowledge/foundations/representation · Foundations · Updated 2026-10-19 © 2026 Rayon. Quote short excerpts with a link to the source page. Full terms: https://guide.rayon.design/about ## Introduction Before anything is built, a room exists as drawings. Each standard view cuts through it or faces it in a different way, so that a client can picture it and a contractor can build it. The [plan](https://guide.rayon.design/lexicon/plan), [section](https://guide.rayon.design/lexicon/section) and [elevation](https://guide.rayon.design/lexicon/elevation) set out its sizes; the [axonometric](https://guide.rayon.design/lexicon/axonometric), the perspective and the render show how it fits together and how it will feel. ## Draw in 2D Three views of the bedroom. Designers think and communicate in a few standard drawings, each answering a different question. Where a drawing cuts through solid material (walls, floors), it is filled in or drawn heaviest; what lies beyond the cut is drawn lighter; hidden or overhead lines are dashed. *Interactive diagram:* The bedroom from above: walls, window, bed, desk and wardrobe, and the door swinging round its hinge. ### Plan A horizontal cut, usually about 1.2 m above the floor, looking down. It shows layout, walls, openings, furniture and [circulation](https://guide.rayon.design/lexicon/circulation), and is where clearances are drawn and checked. *Interactive diagram:* The bedroom cut across the bed, looking at the window: a level glides with the pointer and lights the bed, sill, head and ceiling. ### Section A vertical cut through the room, here across the bed, looking towards the window. It shows heights: floor and ceiling, sills, the bed and lamps against the wall. *Interactive diagram:* The window wall straight on: the curtains part as the pointer nears the window, over the desk below the sill. ### Elevation A straight-on view of one wall. Here the window wall: it positions what sits on the wall, from windows and curtains to joinery, art, sockets and switches. Every 2D drawing sorts its lines by where things sit against the cut, so it reads at a glance. What the cut passes through, walls, a cupboard or a worktop at the cut’s height, is drawn heaviest, often hatched or filled in. What lies beyond the cut and can be seen, the furniture below a plan’s cut or the far wall in a section, is drawn in a thinner line. What is hidden, above a plan’s cut or behind something, such as wall cupboards, beams or a change in the ceiling, is drawn dashed. Move the cutting plane through the room to see each part change. *Interactive diagram:* A cutting plane through a room: what it cuts is filled, what lies below is seen, what lies above is hidden, dashed. *A cutting plane through a room: what it passes through is cut and hatched, what lies below is seen, what lies above is hidden.* ## Axonometric The room in three dimensions, still to scale. An axonometric shows three faces of a space at once but keeps every parallel line parallel. Nothing shrinks with distance, so lengths along each of its three axes can still be measured off the drawing. That makes it the drawing for explaining how parts fit together: how joinery is assembled, how a ceiling steps, how one room leads to the next. It is why this guide’s apartment is drawn this way. *Interactive diagram:* One cube in isometric, dimetric and trimetric: the angles its edges make with the horizontal, and the scale along each axis, change; parallel lines stay parallel. ## Diagrams One idea per drawing. A diagram strips a drawing back to the one thing it needs to explain. Drawn over the same plan or axonometric, each answers a single question: how people move through the flat ([circulation](https://guide.rayon.design/lexicon/circulation)), what each room is for and how the uses group (the [program](https://guide.rayon.design/lexicon/program)), and which rooms are loud and which need quiet ([zoning](https://guide.rayon.design/lexicon/zoning)). Keep each to one idea, with tint and line doing the work and the plan quiet beneath them. *Interactive diagram:* One flat's plan drawn three ways: the route through it, its rooms by use, and its loud and quiet zones. *One flat’s plan in axonometric, drawn three ways: the route through it, its rooms by use, and its loud and quiet zones.* ## Perspective Drawing what the eye sees. A perspective draws a room as a person standing in it would see it. Things shrink as they move away, and lines that are parallel in the room converge on the drawing: each set of horizontal parallels meets at a **vanishing point** on the horizon, and the horizon always sits at the eye’s height. Face a wall and the lines running away from you meet at one point: one-point perspective. Look into a corner and each wall runs to its own point: two-point. Tilt the view up or down and the verticals converge as well, which is three-point, and why interior views are kept level. *Interactive diagram:* A block drawn in two-point perspective from its plan: the picture plane and the eye, sight lines to the corners, vanishing points on the horizon, then true heights carried to them. ### Rendering From line work to the finished room. A render starts where the perspective ends: the same camera and the same line work, now given materials and light. Texturing comes first: each surface becomes a [PBR material](https://guide.rayon.design/lexicon/pbr-material), with its colour, roughness and reflections. Then the light is calculated with [global illumination](https://guide.rayon.design/lexicon/global-illumination), so it bounces between surfaces as it does in a real room. The lines fix the geometry and the view; the render shows how it will feel. Keep the two consistent: a render the drawings cannot deliver sets the wrong expectation. The [Rendering](https://guide.rayon.design/knowledge/rendering) chapter covers materials, light and camera in depth. ![Perspective line drawing of a meeting room enclosed in glass and curtains in an open-plan office, with people walking past.](https://guide.rayon.design/img/representation-lines.webp) ![The same view textured: timber on the ceiling, pleated curtains, a terracotta table and a round rug, all evenly lit.](https://guide.rayon.design/img/representation-texture.webp) ![The same view rendered: a warm timber ceiling, sheer curtains behind the glass, a terracotta table and a round jute rug.](https://guide.rayon.design/img/representation-render.webp) ### Perspective The line work: the camera, the geometry and every edge, set before anything is coloured. ### Texturing Materials mapped onto each surface: timber, fabric, terracotta, still under flat, even light. ### Render The light calculated as it bounces between surfaces: the same view, now how the room will feel. ## Questions What people ask most about drawing interiors. ### 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](https://guide.rayon.design/lexicon/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.