What Does "Modular" Really Mean? Prefab Terms

Prefab conversations are full of words that sound technical but mean simple things. If you know a handful of them, you can follow any builder discussion with confidence. This is a plain-language glossary of the prefab multiplex terms that matter most.

Prefab (prefabricated)

The umbrella word. It means any home where parts are built in a factory before they reach your lot, instead of being built entirely outdoors on site. Modular, panelized, and kit homes are all types of prefab.

Modular

A type of prefab where whole rooms are built as finished boxes, called modules, in a factory. They arrive with walls, floors, wiring, and often kitchen and bathroom fittings in place, and a crane sets them on your foundation. Modular is the most complete and usually the fastest prefab method.

Panelized

A type of prefab where the flat parts of the home, the wall, floor, and roof panels, are made in a factory and shipped flat. They are joined together on your lot. Panelized offers more design freedom than modular. We compare the two in the prefab options.

Off-site construction

Another way of saying prefab. It simply means the building happens away from your lot, in a factory, rather than entirely on site. You may hear builders use this term.

Module

A single finished box in a modular build. A multiplex is made of several modules that are joined together. Module sizes are limited by what a truck can carry.

Kit or hybrid

An approach that mixes methods. Some parts come pre-made from a factory and the rest is built on site. It is a flexible middle path between full modular and traditional building.

Set or craning

The day the finished modules are lifted by a crane and placed on your foundation. For a modular build, this often takes only a day or two.

Site work

The work done on your lot: preparing the ground, building the foundation, and connecting services like water and power. Site work happens for every home, prefab or not, and often runs at the same time as the factory build.

Multiplex

Not a prefab term, but worth including. A multiplex is a small building with more than one home on one lot: a duplex (two), triplex (three), or fourplex (four). A prefab multiplex is simply one built mostly in a factory.

What this comes down to

• Prefab is the umbrella term; modular and panelized are types of it.
• Modular builds finished rooms; panelized builds flat panels joined on site.
• Off-site construction means the same as prefab; a module is one finished box.
• Site work happens on your lot for any home and often overlaps the factory build.

Now that the words make sense, you are ready to talk to builders. Tell us your plan on our contact page and we will match you with vetted BC prefab builders, or read our full prefab multiplex guide.

Frequently asked questions

What does prefab mean?

Prefab, short for prefabricated, means a home where parts are built in a factory before reaching your lot. Modular, panelized, and kit homes are all types of prefab.

What does modular mean?

Modular is a type of prefab where whole rooms are built as finished boxes in a factory, then set on your foundation with a crane and joined together.

What is the difference between modular and prefab?

Prefab is the umbrella term for any factory-built home. Modular is one type of prefab. So every modular home is prefab, but not every prefab home is modular.

What is panelized construction?

Panelized means the flat wall, floor, and roof panels are made in a factory and shipped flat, then assembled on your lot. It offers more design freedom than modular.

What does off-site construction mean?

It is another term for prefab. The building is made away from your lot, in a factory, rather than entirely on site.

What is a module?

A single finished box in a modular build. A multiplex is made of several modules joined together. Their size is limited by what a truck can carry.

What does "set" or "craning" mean?

It is the day the finished modules are lifted by crane onto your foundation. For modular builds this often takes a day or two.

What is site work?

The work on your lot: preparing the ground, the foundation, and connecting services. It happens for any home and often runs alongside the factory build.

What is a kit or hybrid home?

An approach that mixes factory-made parts with on-site building. It is a flexible middle path between full modular and traditional construction.

Where can I learn more?

Read our prefab options guide and full prefab multiplex guide, or tell us your plan on the contact page.