BIM Fabrication Drawings & Offsite Engineering

01 — The Challenge

Traditional construction often requires significant fabrication, assembly, and coordination activities to take place directly on site.

This can result in:

• High levels of site-based fabrication

• Congested construction sites

• Repetitive installation activities

• Coordination issues discovered during installation

• Material wastage and rework

• Inconsistent fabrication quality

• Limited control over fabrication environments

• Labour-intensive site operations

• Delays caused by fabrication and installation conflicts

• Difficulty coordinating prefabricated assemblies with actual site conditions

• Lack of detailed information for manufacturers and fabricators

• Design changes affecting fabrication and procurement

• Inefficient material movement and installation sequencing

Offsite engineering requires more than detailed drawings. It requires coordinated digital information that considers fabrication, assembly, transportation, installation, and site interfaces from the beginning.

02 — VDEC Solution

VDEC provides an integrated BIM-to-Fabrication and Offsite Engineering workflow that transforms coordinated design information into production-ready engineering deliverables.

Our team supports the complete digital process from design coordination through fabrication and site installation.

BIM-to-Fabrication

• Fabrication-Level BIM Modeling

• LOD 400 BIM Development

• Component-Level Detailing

• Assembly Modeling

• Fabrication Drawings

• Shop Drawing Development

• Spool Drawings

• Installation Drawings

MEPF Offsite Engineering

• HVAC Prefabrication

• Ductwork Assemblies

• Pipe Spools

• Plumbing Assemblies

• Fire Protection Assemblies

• MEPF Modules

• Plant Room Modules

• Equipment Skids

• Supports & Hangers

• Modular MEPF Systems

Structural & Architectural Offsite Engineering

• Structural Steel Detailing

• Steel Assemblies

• Precast Components

• Façade Components

• Modular Architectural Elements

• Metalwork

• Stairs & Railings

• Modular Construction Components

Prefabrication Engineering

• Assembly Development

• Component Breakdown

• Connection Detailing

• Fabrication Sequencing

• Installation Sequencing

• Material Optimization

• Site Interface Coordination

• Transportation Considerations

• Modularization Studies

Digital Construction Support

• 3D Coordination

• Clash Detection

• Constructability Review

• Fabrication BIM

• Installation Planning

• Model-Based Quantification

• Digital QA/QC

• As-Built Updates

VDEC's objective is to make components easier to fabricate, transport, assemble, install, and coordinate, before they reach the construction site.

03 — Deliverables

BIM & Engineering Deliverables

• Fabrication-Level BIM Models

• LOD 400 BIM Models

• Coordinated Fabrication Models

• Assembly Models

• Modular BIM Models

• Component-Level Models

• Installation Models

Fabrication Drawings

• Fabrication Drawings

• Shop Drawings

• Assembly Drawings

• Component Details

• Installation Drawings

• Spool Drawings

• Isometric Drawings

• Connection Details

• Support & Hanger Details

• Cutting / Manufacturing Information

MEPF Offsite Deliverables

• Duct Fabrication Drawings

• Pipe Spool Drawings

• MEPF Module Drawings

• Prefabricated Rack Drawings

• Equipment Skid Details

• Plant Room Module Details

• Support & Hanger Drawings

• Sleeve & Opening Drawings

• Installation Sequencing Information

Structural / Architectural Deliverables

• Structural Steel Fabrication Drawings

• Connection Details

• Assembly Drawings

• Precast Details

• Façade Fabrication Drawings

• Metalwork Details

• Stair & Railing Fabrication

• Modular Component Drawings

Digital Production Information

• Material Schedules

• Bill of Materials

• Component Schedules

• Assembly Lists

• Fabrication Tags

• Part Identification

• Quantity Information

• Revision Records

• Installation Information

04 — Our Process

01. Project & Offsite Strategy

We review the project requirements, BIM Execution Plan, design information, construction methodology, fabrication capabilities, project schedule, and intended offsite construction approach.

02. Design & BIM Review

Our team reviews the available BIM models and drawings to understand design intent, interfaces, constraints, LOD requirements, and fabrication requirements.

03. Constructability & Modularization Review

We identify opportunities to move suitable construction activities from site to controlled fabrication environments.

This may include:

• MEPF modules

• Pipe spools

• Duct assemblies

• Equipment skids

• Plant room modules

• Structural assemblies

• Façade components

04. Multidisciplinary Coordination

Architecture, Structure, HVAC, Electrical, Plumbing, Fire Protection, and specialist systems are coordinated before fabrication information is finalized.

05. Fabrication-Level BIM Development

Components are developed with the required geometry, dimensions, connections, materials, interfaces, assemblies, and installation information.

06. Fabrication Drawing Production

Detailed production drawings are generated from the coordinated BIM environment, including fabrication dimensions, assembly information, material data, connections, and installation requirements.

07. Digital QA/QC

Our quality process verifies:

• Geometry

• Dimensions

• Connections

• Materials

• Quantities

• Coordination

• Assembly information

• Drawing consistency

• Model-to-drawing accuracy

08. Fabrication & Assembly Support

We provide digital information required by fabricators and manufacturers for production, assembly, identification, and quality control.

09. Site Installation Coordination

Fabricated components are coordinated with site conditions, access requirements, installation sequence, interfaces, and builders' work.

10. As-Built & Handover

Where required, fabrication and installation information can be incorporated into the final BIM environment to support as-built documentation and digital handover.

05 — Software & Technology

VDEC uses industry-standard BIM and engineering technologies to support digital fabrication and offsite engineering workflows.

Autodesk Revit | AutoCAD | Navisworks | Autodesk Construction Cloud (ACC) | BIM 360

Our workflows can also integrate with client-specific fabrication standards, BIM Execution Plans, Common Data Environments, manufacturer requirements, detailing standards, and project information systems.

06 — Benefits

Move Work from Site to Factory

Identify suitable construction activities for controlled offsite fabrication and assembly.

Improve Construction Productivity

Reduce repetitive site activities by delivering pre-coordinated and pre-assembled components.

Reduce Site Rework

Coordinate fabricated components digitally before manufacturing and installation.

Improve Quality Control

Move fabrication into controlled environments where processes can be standardized and monitored.

Reduce Site Congestion

Prefabricated assemblies can reduce the amount of fabrication, storage, and material handling required on site.

Improve Installation Speed

Pre-coordinated assemblies can support faster and more predictable installation.

Reduce Material Waste

Accurate digital fabrication information helps reduce cutting errors, incorrect fabrication, and unnecessary material use.

Improve Coordination

Fabrication-level BIM provides better visibility of interfaces between manufactured components and building systems.

Support Modular Construction

Develop repeatable modules and assemblies that can be manufactured, transported, and installed efficiently.

Improve Cost Predictability

Better fabrication information helps reduce uncertainty associated with site fabrication, rework, and installation.

Create a Digital Thread

Connect design → BIM → coordination → fabrication → assembly → installation → handover within one information workflow.

07 — Example Project

Offsite MEPF Engineering for a High-Rise Commercial Development

Project Type: High-Rise Commercial / Mixed-Use Development
Scope: BIM Coordination + Fabrication Modeling + Offsite Engineering
Disciplines: HVAC + Plumbing + Fire Protection + Electrical
LOD: 400
Deliverables: Fabrication BIM + Spool Drawings + MEPF Modules + Installation Information

VDEC Approach

VDEC supported the project team in transitioning selected MEPF installation activities from conventional site-based construction toward offsite fabrication and modular assembly.

The team first reviewed the coordinated BIM models to identify suitable areas for prefabrication.

High-density MEPF zones were analyzed for opportunities to develop:

• Pipe spool assemblies

• Duct assemblies

• MEPF service modules

• Equipment connections

• Supports and hanger assemblies

• Plant room components

The assemblies were modeled and coordinated against architectural and structural conditions before fabrication drawings were developed.

Each assembly was assigned appropriate identification and installation information to support fabrication, logistics, and site installation.

Outcome

The BIM-to-fabrication workflow provided the project team with more predictable fabrication information, improved coordination between trades, reduced site-based fabrication, and better support for modular installation.

08 — From Digital Model to Physical Assembly

The future of construction is not simply about building better models.

It is about using digital engineering to build more efficiently in the real world.

VDEC connects BIM, fabrication detailing, engineering, prefabrication, and construction to help clients move suitable work from congested construction sites into controlled offsite environments.

Whether you need MEPF prefabrication, pipe spools, duct assemblies, modular systems, structural fabrication, façade components, or complete BIM-to-fabrication workflows, VDEC can support your project from digital design through installation.