Floor Plan vs Elevation vs Section: What Each Drawing Tells You

Three cuts through the same building

Plans, elevations and sections are all orthographic drawings: parallel projections with no perspective. That is what makes them measurable — a dimension scaled off the drawing is a real dimension.

They differ in where the imaginary cut is taken and where the viewer stands.

Floor plan

A horizontal cut through the building, conventionally about a metre above floor level, viewed from above with the top half removed.

Shows: room arrangement and adjacency, dimensions, wall thicknesses, door and window positions, circulation routes, fixtures, stairs, and the direction they run.

Cannot show: ceiling heights, level changes between rooms in any real detail, roof form, or how the walls are built up.

Conventions: walls in the cut are drawn heavy. Doors show their swing. Items above the cut plane are dashed. Stairs carry an arrow and usually a break line.

Elevation

A flat, straight-on view of one exterior face of the building, drawn as if viewed from infinitely far away so nothing converges.

Shows: the external appearance of that face — proportion, window arrangement, material changes, roof profile against the sky, heights of visible features.

Cannot show: anything about the interior, anything on another face, depth or recession in any reliable way. A deeply recessed window and a flush one can look nearly identical on an elevation.

Conventions: named by orientation (north elevation) or by relationship (front, rear). Ground line and levels are usually marked.

Section

A vertical cut through the building, viewed horizontally.

Shows: floor-to-floor and floor-to-ceiling heights, level changes, stair geometry, roof structure and build-up, how floors meet walls, the relationship between inside and outside ground level, and the layers of the construction.

Cannot show: anything outside the plane of the cut, or the overall arrangement of a floor.

Conventions: the section line and its viewing direction are marked on the plan. Cut material is hatched or poched.

Which answers which question

Question	Plan	Elevation	Section
How big is this room?	Yes	No	Height only
What is this room next to?	Yes	No	Partially
How do I get from here to there?	Yes	No	Vertically only
How tall is the ceiling?	No	No	Yes
What does the street see?	No	Yes	No
Where does the roof drain?	Partially	Partially	Yes
How thick is the wall build-up?	Thickness only	No	Yes
Is there a step between these rooms?	Marked, not explained	No	Yes

Where misunderstandings happen

Approving a plan and assuming the section follows. Ceiling heights, level changes and roof form are decided in section. A plan that reads well can sit under a roof that produces awkward heights.

Treating a render as a specification. Renders communicate intent. They are not measured, they are often produced before materials are fixed, and details in them are frequently indicative. If something in a render matters to you, get it confirmed on a drawing or in the specification.

Reading depth off an elevation. Recession, reveal depth and shadow are exactly what an elevation flattens. Ask for a section or a detail.

Assuming one plan covers the building. Each floor has its own plan, and the roof usually has one too. Differences between them are where a lot of coordination problems hide.

What to ask for and when

During concept and schematic design, plans do most of the work — see how to read a house floor plan. Ask for a section as soon as heights, levels or the roof come up, which is earlier than most clients think.

Which drawings you receive, and when, is set by the appointment — see what does an architect do — and by the stage the project has reached, covered in the five stages of architectural design and the architectural design process guide.

By design development you should expect plans, elevations and sections that agree with each other. Disagreements between them at that stage are the coordination issues worth raising.