Interior Design Fundamentals and Space Planning
What this domain tests
This domain tests whether you can convert a client brief into a plan that works functionally, dimensionally, and accessibly. Expect programming diagrams, adjacency logic, circulation widths, anthropometric clearances, and universal-design checks.
Core rules and concepts
- Programming separates goals, facts, concepts, and needs. Net assignable area excludes corridors, walls, and mechanical space; gross area includes them. Use net for room fit and gross for lease or building efficiency.
- Bubble diagrams test adjacency, not size. Blocking plans add approximate dimensions and circulation; final plans must reconcile structure, egress, and accessibility.
- Anthropometrics sets furniture clearances. A seated worker needs roughly 30 in of desk width; a main aisle behind seated occupants is often 36-44 in; a wheelchair turning circle is 60 in diameter.
- Universal design requires 30 x 48 in clear floor space, 36 in accessible routes, 60 in passing spaces, and 15-48 in reach ranges. Door clear width is 32 in.
- Zone public, private, service, and staff areas. A copy room beside a quiet office is a functional error even when it fits.
Worked example
A 20 x 30 ft conference room has a 6 x 12 ft table, 12 chairs, and a credenza. Deduct a 4 x 10 ft closet: 600 - 40 = 560 sf net. Center the table and keep 36 in behind chairs; a credenza projecting 18 in reduces the usable side aisle. Check that door swings miss chair zones and the accessible route stays 36 in clear.
Traps
Confusing net and gross area; drawing furniture before checking door swings; treating the 60 in turning circle as a route width; and ignoring columns that break a clean bay.