Prefab vs. Modular: Can You Tell The Difference?

Many people don’t understand the difference between prefab vs. modular construction. Prefab is a general term for prefabrication, or building a structure in a factory before assembling it at a construction site, while modular buildings, more accurately called prefabricated prefinished volumetric construction, are structures that are at least 70% prefabricated.

All modular buildings are prefab, but all prefabs aren’t modular. Other kinds of non-modular prefab construction include light gauge steel, flat pack, and steel frame. Builders have many different ways to put these materials together, and each has its benefits and limitations.

Modular construction looks a bit like stacking LEGO blocks. Containers are made almost entirely in a factory, and sometimes even the wiring and fixtures come pre-fitted. That’s how builders recently assembled the world’s tallest modular building in Melbourne Australia.

One industry that modular is impacting the most is hospitality. Developers looking for quicker and more affordable ways to complete multi-story structures are finding the method ideal. As a result, large modular projects are coming to be considered less experimental as Hampton, CitizenM and Holiday Inn construct their hotel rooms in factories.

While modules look like shipping containers — and are sometimes made of converted shipping containers — a prefab house made of steel gauge will have a frame that looks a lot like a stick-built house. Light gauge steel is the most common prefab method for residential homes. But there are other prefab building methods which can work for larger structures too like the 57-storey Mini Sky City in Changsha, China that was built in just 19 days. It’s also fast, safe, and produces much less waste than traditional construction.

Think you could tell the difference between prefab vs. modular?