Design Drawings vs Construction Drawings: The Difference

The design stages in brief

Every project passes through a series of stages, and each stage produces a set of drawings with a different purpose:

1. Concept: an initial space layout, a massing study and 3D visuals to choose a direction.
2. Schematic Design: plans with main dimensions, preliminary elevations and sections, and an area schedule.
3. Design Development: fixing the structural system, the main services routes and the principal materials.
4. Permit drawings: the set the licensed office submits through the Balady platform to obtain the building permit.
5. Construction documents (IFC): a complete set with dimensions, levels, details and specifications, from which the project is tendered and built.
6. Shop drawings: prepared by the contractor after award and approved by the consultant before fabrication and installation.
7. As-Built drawings: record what was actually built at handover.

The first three stages are what we call "design drawings". Their purpose is decision making: is the layout right, is the facade acceptable, does the budget cover it? Construction drawings exist so that the contractor can build without having to ask.

What do design drawings contain?

• Plans showing the space layout and overall dimensions, without detailed dimensions for every wall and opening.
• Preliminary elevations and sections showing general heights and massing.
• 3D visuals, material boards and colour suggestions.
• An area schedule for the floors and spaces.
• The structural system concept and preliminary column locations.

What do construction drawings contain?

• Architectural: plans with full dimensions, grids and levels, wall types, a reflected ceiling plan, door, window and finish schedules, and details for bathrooms, kitchens, stairs and facades.
• Structural: the foundation plan and reinforcement details, columns and necks, slabs and beams, stairs, general notes on loads and materials, and the calculation report.
• MEP: lighting, power, distribution boards and the single line diagram, water supply and drainage, HVAC and ventilation, fire alarm and fire fighting, and low current.
• Supporting documents: the technical specifications and the bill of quantities (BOQ).

Quick comparison

Permit drawings are not construction drawings

Permit drawings show that the building meets the statutory requirements: setbacks, heights, built-up ratio and code requirements. But they usually do not contain finishing details, services coordination, or door and finish schedules. Starting construction from them alone means many decisions will be made on site with no reference, which is a main source of variations and disputes. Code requirements are explained in Saudi Building Code (SBC) requirements in drawings.

Who is responsible for each set?

The designer is responsible for the construction drawings being complete, coordinated and compliant with the code and specifications. The contractor is responsible for building to them and for the shop drawings it prepares. The supervising consultant reviews, approves and follows up compliance on site. When a project is built from design drawings these responsibilities blur: the contractor fills in the details at its own discretion, and when a defect appears the question becomes whether it is a design error or a construction error. Having an approved construction set is what makes the answer clear.

What happens if you build from design drawings?

• Quotes that cannot be compared, because each contractor assumes different materials and details.
• Clashes between air ducts, beams and ceiling levels discovered after the concrete is poured.
• Repeated change orders that raise the cost and delay the programme.
• Difficulty at handover, because there is no clear reference for what should have been built.

How do you know the set you received is really a construction set?

Open the drawings and ask the questions below. If the answer is "no" to more than two of them, the set is a design set, whatever its cover says:

• Does every wall and opening have a written dimension tied to a grid, so no one has to scale it with a ruler?
• Is there a door and window schedule with sizes, types and ironmongery?
• Is there a finish schedule for each room: floor, walls, ceiling and skirting?
• Is there a reflected ceiling plan with levels and the locations of lighting and air conditioning?
• Are there large-scale details for bathrooms, kitchens, stairs and facades?
• Do the structural drawings include full reinforcement details and general notes on loads and materials?
• Do the MEP drawings include load schedules, a single line diagram and routes coordinated with the beams?
• Are there written technical specifications and a bill of quantities linked to the drawings?

What should you hand the contractor with the construction drawings?

The drawings alone are not enough to tender a project. Attach the technical specifications, the bill of quantities or the approved method of measurement, the drawing register with revision numbers, the soil report, and any requirements from the owner entity or developer. In the tender documents, state what the contractor must submit in the way of shop drawings, samples and approvals before execution, so that bids arrive on one basis and can be compared. On award, all of this is agreed in the project kick-off meeting.

Where do shop drawings come in?

After the construction drawings are approved and the project is awarded, the contractor converts them into shop drawings with the actual dimensions and materials it will supply, and submits them to the consultant. The difference is explained in Shop drawings vs construction drawings, and the pre-submission review list is in the shop drawing submittal checklist.

How we work in both cases

If you have an approved design, we prepare the construction drawings for all disciplines, or the shop drawings for the contractor, remotely. If you are at the start, we begin with architectural design and finish with a complete construction set. The cost is explained in Construction drawings cost in Saudi Arabia.

Frequently asked questions

What is the difference between design drawings and construction drawings?

Design drawings explain the idea, layout and form so decisions can be made. Construction drawings are a complete set with dimensions, levels, details and specifications for every discipline, from which the project is priced and built.

Are permit drawings enough for construction?

Usually not. Permit drawings show that the statutory requirements are met, but they do not contain the finishing details, services coordination, and door and finish schedules needed for construction.

What scales are used in construction drawings?

1:50 is common for plans and sections, and 1:20 to 1:5 for details, while design drawings are usually drawn at 1:100 or 1:200.

Are shop drawings part of the construction drawings?

No. The designer issues the construction drawings before tender, while the contractor prepares the shop drawings after award and submits them to the consultant for approval before fabrication and installation.