“From Design to Construction: What Are the Project Stages, and How Does BIM Fit In?”

Introduction

For a long time, I have noticed that some people confuse the different levels of detail in BIM, or what is called LOD (LEVEL OF DETAILS). You might see someone publish a post with drawings that do not go beyond LOD 200, yet describe them as LOD 400—and sometimes even LOD 500…

Original image from LinkedIn

So let’s understand the project stages and the requirements of each stage, alongside the BIM outputs produced at each one…

LOD 0 — Brief

This is the stage for studying the project and the site, making a few sketches, and discussing the client’s “two falafel patties and a cup of tea”—otherwise known as the budget. The outputs are the project programme and its studies…

Concept Design / Schematic — LOD 100

At this stage, the architect works on the design after studying the project, its spaces and all those considerations, and begins to develop a design that can be built. This stage generally does not need involvement from any of the other disciplines…

But when the project is a renovation (meaning an existing building is being refurbished), an interior designer may join us at this initial stage. If there are no major internal changes, they can get started on their design…

The structural engineer may also come in to carry out investigations. For example, if we are adding another storey, they start by checking whether the foundations can support it, along with other necessary checks…

These projects are very rare in the Arab world. In Europe, it is quite the opposite: most projects there are of this kind. In other words, 95% of projects in the Arab world are buildings constructed from the ground up, while 95% of buildings in Europe are existing buildings undergoing renovation…

Architectural outputs at this stage

A — For a new-build project

1. Basic architectural model
2. Rendering images
3. Concept drawings

• Site plan
• Floor plans
• Elevations
• Sections

B — For a renovation project

1. Existing model, demolished model, proposed model
2. Render images
3. Drawings

• Existing and demolition drawings
• Site plan
• Floor plans
• Elevations
• Sections

At the end of this stage, we may produce authority drawings so that the project can be approved by the relevant bodies responsible for urban planning, laws and regulations, whatever their names may be in each country.

Images from this stage of some projects I have worked on…

LOD 200 — Design Development / Detailed Design (DD)

After the concept stage and design approval, we begin developing the project in more detail. We resolve architectural issues in general so that the structural and MEP disciplines can join us, while the interior design work is already under way. This stage is usually split into DD 50% and DD 100%, so we can see whether all the disciplines are working together or whether there are problems…

Working in architecture and interior design, you start adding materials and details based on a study of the elements and related considerations. These come from the manufacturers’ catalogues you used to select materials for the design; we do not just put anything anywhere, as we sometimes see. We receive samples, the client confirms and approves them, and we produce the specifications (SPECS) and BOQ on that basis…

Architectural outputs at this stage

1. Updated architectural BIM model
2. Drawings

• Overall / partial floor plans
• Elevations
• Sections
• Wall sections
• Assembly drawings (stairs, lifts, railings, louvers, etc.)
• Door schedules
• Window schedules

Interior outputs at this stage

1. Updated interior BIM model
2. Drawings

• Setting-out plans
• Partitions and wall linings
• Wall finishes
• Floor finishes
• Reflected ceiling plans (RCP)
• Furniture plans
• Power plans
• Interior elevations
• Bathrooms
• Kitchens

LOD 300 — Technical Design / Tender Documents (TD)

The tender stage is when the project is put out to contractors. Its importance lies in the fact that every element in the project must have a description and a code linked to the specifications. For example, you cannot have a wall without a code and a description reflected in the specifications. The specifications must explain everything about that element’s installation, suppliers and other requirements, as mentioned earlier.

All of this matters so that the contractor can price the project…

Once the contractor has priced the work, a copy goes back to the consultant. At the same time, final coordination takes place between architecture, structure and MEP—and, of course, there are plenty of headaches…

Finally, the contractor receives the final BIM models and documentation, including drawings, specifications, BOQ and the complete IFC (ISSUE FOR CONSTRUCTION) package, with all the required details.

Architectural outputs at this stage

1. Updated BIM model
2. Drawings

The same as the previous stage, with the addition of:

• Facade details
• External envelope details
• General details (louver details, cladding details, etc.)
• Final specifications

Interior outputs at this stage

1. Updated BIM models
2. Drawings

— The same as the previous stage, with additional information and:

• Bespoke drawings (built-in wardrobes, desks, loose furniture, cladding, etc.)
• Final specifications

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LOD 400 — Construction Drawings / Shop Drawings

This is the contractor’s stage. After receiving the BIM model and drawings from the consultant, the contractor develops them with further construction detail. Everything becomes more detailed, with a focus on final coordination for MEP and structure. A copy is submitted to the consultant for final review, and site work and construction have usually already started by this point…

The outputs at this stage are detailed drawings that go down to the smallest details, according to the project’s needs and scope—and, of course, quantities for everything…

Some shop drawings relate to architecture, while others relate to interiors:

• Blockwork
• Plaster
• RCPs
• Tile layouts
• Finishes
• Waterproofing

And other shop drawings that deserve a post of their own, just like interior design.

Quite often, subcontractors prepare the detailed drawings for certain items, and we incorporate their work into our model and drawings—for example, aluminium details…

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LOD 500 — As-Built / Handover Closeout

This comes after everything on site has been completed. A contractor may have built something and obtained approval without drawings. Once it has been carried out, we update the model and the as-built drawings—in other words, exactly as it ended up on site.

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Notes

1. Not every project has to follow these stages in exactly the same way. Everything depends on the project and its scale: a villa project is not the same as a mall project…
2. The stages from LOD 100 to 300 belong to the consultant. Your role in them sometimes combines BIM with design, so you need to understand that well. LOD 400 is on the contractor’s side, where your role involves coordination, detailed drawings and quantity extraction…
3. In BIM, LOD applies more to elements than to the project as a whole. For example, during concept design you may already have door details, so you create the door family at LOD 300 while the project is still at LOD 100. That is perfectly normal. You might also be at LOD 300 without window details, which the contractor then develops at LOD 400. But LOD 400 means showing the window mullion details, not just a rectangle. The contractor receives those details from the specialist, and so on…

God willing, I will soon post more detailed explanations of these topics on the YouTube channel. It is also worth mentioning that we cover all of this in a BIM diploma; you can find the details here…

To learn what BIM means, you can watch this lecture:

Please write to me with any questions or topics you would like me to discuss. And if you found this useful, share it with your friends…