Interiors: From Concept to Shop Drawings

Interiors often start as early as stage 2, with mood boards and a concept deck. But they are built in stage 8, on walls that now exist. Between the two sits a set of steps that turn pictures into something a carpenter or a factory can make.

Step by step

1. Concept deck. Mood images, renders and layout ideas. As module 2 showed, these often mix CAD snippets, 3D model views and AI images, and they can disagree. They are design intent.
2. Site survey. Once walls and plaster are done, the interior team measures the real rooms: wall lengths, diagonals, ceiling heights, beam drops, column projections, electrical and plumbing points.
3. Shop drawings. Dimensioned plans, elevations and sections of every piece: kitchen, wardrobes, TV unit, ceiling, panelling. Each shows sizes, materials, finish codes and hardware.
4. Material list and BOQ. Board, laminate, veneer, hardware, glass, stone, paint, false ceiling, lights. Quantities are taken from the shop drawings.
5. Approval. The owner signs off shop drawings and samples.
6. Execution. On-site carpentry or factory-made modular units, then installation and snag list.

Tools

• Concept and renders: SketchUp and 3ds Max with V-Ray, Corona, Enscape or D5 Render are commonly seen in Indian interior offices; AI image tools are increasingly used for mood images.
• Shop drawings: AutoCAD, or drawings exported from SketchUp or from modular design software.
• Material lists: Excel, or reports from modular software.

A worked example: the column the deck did not show

A concept deck shows a straight 3.0 m kitchen counter along one wall. The site survey finds a 150 mm deep column projection, 450 mm wide, at 1.2 m from the corner. The model used for the deck had a clean wall.

• Without a survey: carcasses are made for a straight 3.0 m run. At installation, one 600 mm base unit and the wall unit above it do not fit. Remaking them, plus a new counter cut-out, costs about ₹18,000 (illustrative) and a week of delay.
• With a survey: the shop drawing splits the run around the column, adds a 150 mm filler, and adjusts the counter. Cost: an hour of drafting.

When are interior quantities reliable?

Only from the shop drawing onward. Before that, any BOQ is a budget estimate and should say so. If you have to price from a concept deck, write down every assumption: room sizes used, which view governs, what is excluded.

What comes next

Many modular kitchens and wardrobes are now made in factories. The next lesson looks at the software that turns a shop drawing into machine instructions.