Architectural drawings contain more information than most clients realise — and are less intimidating than they look. Here is how to read them and what to look for.
Most renovation clients receive a set of architectural drawings, look at them briefly, and then rely on their architect or contractor to interpret them. This is understandable — drawings are a technical medium, and the conventions used in architectural drawings are not obvious to those who have not learned them.
But being able to read drawings is genuinely useful. Clients who understand their drawings catch errors before construction begins, make better-informed decisions about variations, and have more productive conversations with their design and construction team.
Here is what the main drawing types are and how to read them.
The drawing types you will receive
Location plans (site plan): Shows the property in context — the boundary, the street, and surrounding properties. Typically at 1:1250 or 1:2500 scale. Used for planning applications. The application boundary is shown as a red line.
Block plan: A more detailed plan showing the property and its immediate curtilage — garden, outbuildings, neighbouring properties. Typically 1:500. Used to show the relationship between the proposed development and the site boundaries.
Floor plans: The primary working drawings. A horizontal slice through the building at approximately 1m above floor level, showing the layout of rooms, walls, doors, windows, and fixed furniture. Each floor has its own plan. Typically drawn at 1:50 or 1:100 scale.
Elevations: External views of the building from each side — front, rear, side. Show the appearance of the building including window and door positions, roof line, cladding, and materials. Typically 1:50 or 1:100.
Sections: A vertical slice through the building, showing the relationship between floors, the ceiling heights, the structure, and how spaces connect. Sections are particularly useful for understanding the three-dimensional character of a space — how a double-height void reads, how a staircase relates to the floor above, how a basement connects to the ground floor.
Detail drawings: Large-scale drawings (1:5, 1:10, 1:20) showing specific junctions or construction details — the connection between a window frame and the wall, the profile of a cornice, the junction between a kitchen worktop and a wall. These are produced later in the design process and are typically only provided for complex or bespoke elements.
How to read a floor plan
On a floor plan: - Thick lines represent walls (at the cut level) - Thin lines represent lines below the cut level (floor finishes, furniture, fixtures) - Dashed lines typically represent elements above the cut level (ceiling features, high-level cabinets, roof overhangs) - Door symbols show the door leaf and an arc indicating the door swing — check that the arc does not conflict with furniture or other openings - Window symbols show the window position in the wall; the line through the wall shows the glazing
Scale: Every drawing has a scale notation — "1:50" means one unit on the drawing represents 50 units in reality. If you have a scale rule (or can use an online scale converter), you can measure any dimension on the drawing. If you do not have a scale rule, at 1:50, 1mm on the drawing = 50mm in reality.
What to check on floor plans: - Room dimensions: are they what you expected? Is the kitchen large enough for the island shown? - Door swings: does the bathroom door swing clear of the toilet? - Furniture layouts: is the dining table shown at a realistic size? Is there adequate clearance around it? - Circulation: can you move between rooms in a natural way without passing through other rooms?
How to read an elevation
An elevation shows the external face of the building. Look for: - Window and door positions and proportions — are they consistent with what you expected? - Roof line and parapet height - Material annotations — hatching or notes indicate the material intended for each surface - Height dimensions — the elevation often shows overall building height and eaves/ridge heights
On a planning elevation, the context matters — adjacent buildings may be shown to indicate how the proposed development sits within the streetscape.
How to read a section
A section is arguably the most useful drawing for a client to understand. It shows: - Floor-to-ceiling heights at each level — compare these to what you experience in your current house - The relationship between levels — how a basement connects to the ground floor, how a loft conversion reads from the floor below - Structural elements — beams, columns, rafters — in their correct position - Stair geometry — the section often shows the stair profile, indicating headroom clearances
Dimensions and what to check
Construction drawings should have key dimensions annotated. Check: - Room dimensions against your expectations - Opening sizes for doors and windows — does the bi-fold door span match what you discussed? - Ceiling heights — particularly in loft conversions or basement rooms - Structural element sizes — where a steel beam is shown, the drawing should indicate its depth
Dimensions that are missing from a drawing are a question to raise with the architect — unexplained assumptions are the source of many site disputes.
Drawing revisions
Drawings are revised throughout the design and construction process. Each revision is indicated by a revision cloud (a cloud-shaped outline around the changed area) and a revision letter in the title block (Rev A, Rev B, etc.). When reviewing a drawing, confirm you are looking at the current revision — the date in the title block and the revision letter should both be checked.
If you are marking up a drawing with comments, mark the revision reference alongside your comment so it is clear which version you were reviewing.
When something looks wrong
The most valuable thing a client can do with drawings is raise questions before construction begins. Errors and misunderstandings on a drawing cost nothing to correct before the build starts; they cost significant money and delay once the contractor has begun work to the incorrect information.
Common things to flag: - A room that appears smaller than expected - A door swing that will cause a conflict - A dimension that does not match what was agreed verbally - A material or finish that is not annotated and therefore unclear
ASAAN's approach
ASAAN reviews architectural drawings before construction begins specifically to identify buildability issues, coordination conflicts, and missing information that will cause problems on site. We can walk clients through drawings at any stage to ensure they understand what is being built.
If you are planning a renovation and want help interpreting drawings, contact us.
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