Furniture Design
Scope
Furniture Design tests ergonomics and standard sizes, principles of proportion and function, and material selection - not decoration alone.
Ergonomic standards
- Chair seat height 430–450 mm; seat depth 400–450 mm; backrest top about 850 mm.
- Dining table and desk height 720–750 mm; the seat-to-table clearance (knee space) about 250–300 mm.
- Knee clearance under a desk: at least 600 mm wide, 600 mm deep and 620 mm high.
- Shelves about 300 mm deep for books and 250 mm for general storage; brace an 18 mm shelf beyond about 750 mm span.
Design principles
Function first, then anthropometrics, then structure (grain direction and joint choice), then proportion (golden ratio 1:1.618, repeated modules), then surface. Balance, rhythm and visual weight matter both on the drawing and at marking out.
Boards and sections
Plywood and blockboard for carcase panels, MDF for painted and routed work, solid timber for frames and legs; 25–40 mm for tops, 40–50 mm square for legs.
Worked example
A study table 750 mm high: a 450 mm seat height gives 300 mm clearance, which is comfortable. Knee clearance needs 600 mm width, so a 900 mm table with two 50 mm legs leaves 800 mm - acceptable. Legs of 45 mm square with a 25 mm top give the stiffness needed over a 1.2 m span.
Traps
Designing purely by appearance and forgetting the seated user; specifying a solid top over 600 mm wide without allowing for movement; ignoring grain direction when placing legs and rails; mixing imperial and metric dimensions on one drawing.