Prefab vs Modular Homes: What’s the Difference?

Prefab homes and modular homes are becoming more popular through the years, yet we often confuse one for the other. Read on to understand the nuances between the two.

Prefab or prefabricated is an umbrella term for off-site construction that refers to building a structure or a home in a factory before it’s assembled and installed on-site. Modular construction is just one category of prefabricated homes. Other non-modular, prefabricated construction includes light gauge steel, flat pack, and steel frame.

What is Prefab?

With prefab homes, the prefabricated panels and modules are constructed in a controlled, factory-like environment. These parts are then transported, assembled, and installed on-site to create a complete, liveable home. The types of prefab homes include modular homes, panelized homes, and pre-cut homes.

Home by Tom Dixon

A modular home by Tom Dixon

Billboard House David Salle

A panelized home by David Salle

Strong structural integrity is guaranteed with prefabs through the use of high quality materials. The prefabrication process only begins at the production plant after completing all the necessary permits, site inspections and documentation between you and your prefab house builder.

Modern prefab houses follow precision engineering with strict quality control standards. The process usually begins with an SMEP (structural, mechanical, electrical, and plumbing) engineering assessment, mobilization, and assembly. Multiple test will be conducted to ensure that mechanical, electrical, plumbing, and structural systems are all in proper working order.

Simple House by Jean Nouvel

Simple by Jean Nouvel

In the next phase, punchlisting and final touchups will be performed, where the architect and engineers ensure that the project and workflow checklist is fulfilled to the letter. If everything is aligned perfectly, the process will then move on to the pre-assessment stage, where housing pieces undergo pre-packaging monitoring and post-packaging verification. All necessary state or city permits are also secured at this stage to prepare the new modules and panels for delivery.

Shipping and delivery time will depend on your location. Installation will then take 1 to 2 weeks, once the parts arrive at your chosen site.

This meticulous process ensures that all parts, panels, and modules are in perfect working order to guarantee quality and integrity.

What is Modular?

Modular homes use factory-made, prefabricated units that are delivered to the site in modules. Commonly, the modules consist of six-sided boxes that are put together on-site to create a complete building. They can be laid side by side, end to end, or stacked using a crane to form a vertical structure. Modular homes are usually almost completed before transport and delivery to the site. An example of this would be Philip Johnson Alan Ritchie Architects’ Modular Glass House and Paulo Mendes da Rocha’s Modular Living Unit. Both are being distributed by Revolution Precrafted to make designer prefab homes more accessible to a wider market.

Modular Glass House by Philip Johnson Alan Ritchie Architects

Modular Glass House by Philip Johnson Alan Ritchie Architects

Modular Living Unit by Paulo Mendes da Rocha + Metro

Modular Living Unit by Paulo Mendes da Rocha + Metro

Bottom Line

All modular homes are prefab homes, but not all prefab homes are modular homes. The difference between the two lies in the preconstruction of its parts—prefab home construction involves the prefabrication of its separate sections and structures such as panels or modules, while modular home construction involves the pre-engineering and creation of complete modules or units to be assembled or stacked.

With on-site home construction, it’s difficult to monitor the quality of work being done by each contractor. With prefabricated construction, the quality of each part and section is ensured because each one is created in a factory setting where work is streamlined to each expertise.

Both prefab homes and modular homes are prefabricated to lower home construction time and costs. Prefab homes also provide a more energy efficient and durable home with increased structural integrity. Since prefab homes appraise the same as traditionally built homes, the advantages of getting a prefabricated house far outweigh that of a site-built house.