Everything You Need to Know About Shop Drawings and As-Built Drawings

Feb 14, 2024

Category:  BIM / Digitization / Automation


shop drawing and as built drawing feature image

You’re starting a new construction project, poring over pages of intricate design plans, trying to wrap your head around every minute detail. Or maybe you’re a seasoned pro who has worked on countless builds, but the terminology still gives you pause. What exactly are shop drawings versus as-built drawings, and why does it matter anyway? 

In this detailed blog, we will take you through the details of shop drawings and as-built drawings. We’ll break down everything you need to know in simple terms – from basic definitions to why they’re integral to any building project. Let’s begin!

What are Shop Drawings and As-Built Drawings?

Before we dive further, let’s start with some clear definitions so we’re on the same page:

Shop drawings

These are also known as fabrication drawings. These are technical drawings created by contractors or suppliers. They provide detailed specifications for manufacturing or installing products like structural steel, mechanical equipment, and precast concrete.

As-built drawings

These drawings capture the final completed state of a construction project. This includes any changes made after the original design plans and shop drawings.

The key difference lies in timing. Shop drawings happen early, providing instruction for building. As-builts come at the end, documenting the actual finished product. 

With the basics down, let’s examine why both drawing sets play vital roles.

Why Shop Drawings Matter

You might be wondering, if construction plans already exist, why do we need shop drawings, too? Architectural and engineering plans provide critical information required to build – but shop drawings take it to the next level.

They serve many crucial functions like:

Communication Tool

Miscommunication constantly threatens hectic job sites spanning multiple teams and vendors. They become the standard language to get everyone on the same page.

Construction Blueprint

While the architectural plans provide the what and the where they drill down into the how-how things go together. They offer build instructions so granular you could assemble major systems using the drawings.

Quality Control Guide

With clear specifications and tolerances, they empower teams to engineer, fabricate, and install materials to exact specifications the first time. This prevents costly errors and rework down the road.  

Project Coordination Tool

Shop drawings illustrate how all the puzzle pieces fit together on multi-system builds. This helps coordinate teams and sequences of work so everything interconnects smoothly.

What is Included in Shop Drawings

Now you know why shop drawings matter for any major build – but what exactly should they include? The level of detail depends on the product or system. Still, some typical components are

♦ Dimensions – Correct sizes, lengths, and heights accurate to the millimeter

♦ Materials – Every material type, grade, and finish called out 

♦ Assembly Instructions – Mechanical drawings of how parts connect

♦ Fabrication Details – Cutting, drilling, welding, and machining methods   

♦ Quality Standards – Tolerance limits, testing procedures, and codes

♦ Attachments – Spec sheets, product data, calculations

Shop drawings get incredibly granular. For concrete reinforcement, they specify each steel bar’s shape, size, length, quantity, and where it goes. This extreme precision prevents errors and misaligned expectations that manifest in big problems and cost overruns later.

Creating and Reviewing Shop Drawings   

Shop drawing creation varies by industry and specific systems involved, but some examples of who creates them include:

♦ Structural Engineer – Steel fabrication 

♦ Mechanical Engineer – HVAC, plumbing 

♦ Electrical Engineer – Lighting, fire detection 

♦ Architect – Custom architectural elements

Once created, shop drawings undergo intensive review and approval before work proceeds:

♦ General Contractor – Ensures constructability 

♦ Architect/Engineers – Confirm alignment with design intent 

♦ Building Officials – Verify code compliance

♦ Owners – Weigh in on expectations  

This failsafe helps spot issues early when they are still easy to correct. Can you imagine trying to swap out the entire concrete foundation after it’s poured and cured because the drawings weren’t thoroughly reviewed? 

Digitizing the Process

In the past, painstaking hand drafting was the only way to generate shop drawings. Updates meant erasing, scribbling, and starting over. Today, CAD programs create precision drawings quickly, easily accommodate revisions, simulate assemblies in 3D, and more.  

Tablets and mobile apps even empower onsite teams to instantly redline changes rather than radioing back to the trailer and hoping the message translates accurately. Most major contractors and vendors have digitized shop drawing processes to streamline coordination and optimize builds.

Why As-Built Drawings Matter

You can have the most buttoned-up shop drawings ever created, but changes happen when the second tools hit materials. The construction process is filled with imperfections, forcing tweaks to the plan. Items get relocated; designs switch mid-project; improvements occur organically in the field. This real-world iteration from the original vision to the completed structure is exactly what as-built drawings were created to capture.  

As-builts serve several critical functions:

Permanent Record

Long after work crews depart, as-builts provide future owners, facility managers, and maintainers an accurate reference of precisely what got built and where – invaluable for renovations, additions, and repairs.

Informs Operation & Maintenance

As-builts contain nitty gritty operating and maintenance details overlooked during design – valve shut-offs, wiring diagrams, and access points. This empowers smooth facility function.

Supports New Teams

Instead of new trades reinventing the wheel if issues arise, as-builts let them hit the ground running with the project’s real specifications.

Confirms Work Scope

As-builts provide proof to owners, inspectors, and insurers that work matches permits and meets the code.

What to Include in As-Built Drawings  

To be useful, as-builts must thoroughly capture every system’s final form. Details should include:  

♦ Actual Dimensions – Of walls, duct runs, finished spaces

♦ Altered Layouts – Relocated windows, doors, plumbing  

♦ Substituted Materials – Pipe type, gauge changes 

♦ Reroutes – Ducting, wiring, piping in new places

♦ Builder Improvements – Extra insulation added  

♦ Modifications from Corrections – Post-inspection tweaks  

♦ Dates Changes Occurred – Helps track decision timeline

As-builts also incorporate all supporting documents throughout construction – RFIs, submittals, photos, change orders, and more. Think scrapbook meets operations manual. The richness of this complete package enables owners to optimize their investments continually for years to come.

Creating As-Builts Over the Life of a Project

Ideally, as-built documentation starts from day one. Tradespeople log alterations as they happen on tablets that sync updates to a central cloud-based construction platform. This real-time field-to-office information flow keeps as-builts accurate and aligned with the latest progress. When it comes to project turnover, everyone already knows the final build specifics. 

Some best practices include:    

♦ Take Pre-Construction Photos – Useful baseline of original site conditions

♦ Label All Photos – With location, direction, and date to help decipher later   

♦ Share a Central Platform – Ensures one single source of truth  

♦ Standardize File Organization – Quick retrieval for years  

Building robust as-builts incrementally from the get-go saves major time and errors versus trying to recreate intricate details after the fact.

Leveraging Technology

Remember the days of cumbersome paper as-builts stuffed in tubes sitting in job trailers collecting dust? Thankfully, technology has revolutionized this document-laden process, providing anytime access and far more utility.  

Cloud-based construction platforms offer powerful permanent homes for as-builts with game-changing capabilities:  

♦ Central Repository – All project data in one searchable system

♦ Unlimited Image Hosting – Attach photos, videos, documents 

♦ Robust Permission Controls – Custom access for each party  

♦ Automated Version Tracking – Every set iteration saved

♦ Real-Time Updates – Changes sync instantly to all stakeholders  

♦ Future-Proof Durability – Access decades down the road   

This enables all teams to build a rich living narrative of the structure as it takes shape while supporting asset management long after. Digitized as-builts are truly built to last.


We’ve covered multiple pieces of information on the what, why, and how behind shop drawings and as-builts. These two documentation sets are fundamental to construction projects of any type, scale, or industry. 

Though created separately and for distinct purposes, shop drawings and as-builts work in tandem over the building lifecycle:

Shop drawings – Provide instructions to create the initial structure 

As-builts – Capture the final actual structure.

By mandating detailed plans upfront while also allowing flexibility for real-world variability this balanced mix empowers optimised builds. And just like the structures, they help manifest digitized shops.

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Q1. What are shop drawings and as-built drawings?

Shop drawings are done before the construction begins. You can change it in the pre-development stage. In as-built drawings, you can’t change anything after project completion; however, they can be changed during renovation or maintenance works.

Q2. What is the reason for shop drawings?

Shop drawings convey the design purpose and concept. It gives builders the information they need to create, construct, assemble, and integrate a building's components. The key reasons for shop drawing are Coordination, Detail, Quality Control, Manufacturability etc

Q3. What are the colors of as-built drawings?

A standard color code scheme is used in as-built drawings to enhance readability and understanding. This helps quickly identify modifications made during construction compared to the original plan. Crucially, maintain the same scale as the original drawing when adding these color-coded modifications. This ensures consistency and prevents misinterpretations.