Learning Center

November 22, 2019

What Are the Components of a Modular Building?

Modular buildings consist of on-site foundations, structural frames, finishes, utilities, and marriage joints.


When viewing a finished, large-scale modular building, it can be difficult to imagine all of its components. The fact is, though, that at one point in its past, that building was actually countless pieces moving through an assembly facility. So, while the quality and beauty of the finished structure attracts the most attention from developers, it's important to understand what exactly goes into a modular building. 

From its steel to its light fixtures, a modular building is comprised of thousands of different parts. Virtually all fall into one of the following six major component categories:

1. On-Site Foundation 4. Plumbing, Electrical, HVAC
2. Structural Frame 5. Interior Finishes
3. Exterior Finishes 6. Marriage Joints


1. On-Site Foundation

Modular construction can move most of the building process into an off-site facility, with units assembled along a production line. Even the most advanced modular processes, however, incorporate some element of on-site construction.  

This includes the building's excavation, footings and foundation, and takes shape while its other components are being assembled in the manufacturing facility, contributing to the overall efficiency of modularization

2. Structural Frame

A modular building is comprised of modular units, each supported by a structural frame around which the rest is assembled. 

This will typically feature six sides and be made of wood or steel. The latter, such as those assembled by Deluxe Modular, offer greater strength and long-term durability, and enable buildings to reach greater heights than those built of wood.

3. Exterior Finishes

In traditional construction, exterior finishes are one of the last features to be completed. Modular construction does so much earlier in the process, however, working from the outside of a unit, in. This includes siding, exterior light fixtures, windows and doors

A protective wrapping added later in the process will safeguard these finishes during the transportation and installation stages

4. Plumbing, Electrical & HVAC

Utilities such as plumbing, electrical and HVAC are added to the unit after the exterior finishes. These are then sealed in preparation for travel, and later, installation. 

5. Interior Finishes

Interior finishes include typical aspects, such as walls, flooring, and countertops. Modular construction differs from traditional construction in its ability to go even beyond these standard finishes. 

Full-service modular manufacturers, such as Deluxe Modular, can ensure specific features, including furniture and appliances, for example, are present in each unit before being set in place

6. Marriage Joints

The last major component of a modular building is the marriage joints holding the units together. Though not visible, these connections are responsible for ensuring each module remains fastened to those around it, forming the coherent building. 

As the units are lifted and lowered into place, construction crews make sure each is secure, while attaching its utility systems. 

To learn more about modular construction, download the free Ultimate Guide to Modular Construction eBook. 

Topics: Modular Construction

Read Next: The Ultimate Guide to Modular Construction

This guide is intended to help you sort through the confusion, give you an in-depth understanding of the modular construction process, its benefits and challenges, and help you determine if modular construction is right for you.

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