Modular buildings, or prefabricated buildings, are the new trend in building construction. They consist of building units or rooms that are factory-built using heavy engineering processes and later assembled on-site. Steel is the basic material used to construct singular units. However, modular buildings are also made using concrete, bricks and mortar.

The construction of modular buildings is simple compared to conventional construction, as no foundations are necessary. Builders visit the site and supervise the plot on which the building is to be erected. Using expert architects, floor plans are drawn. Then the builders decide how to fragment the plan into separate units. Each unit is then constructed differently in a factory. When this is done, all the units are installed on location and packed together using cement and mortar, or welded and bolted to each other. Some heavy buildings may need stone slab foundations in order to improve their sturdiness.

Modular buildings are being appreciated worldwide for their speed of construction. An entire building can be erected within a year, and that too without much work on the site itself. Since foundations are redundant in most of the cases, the entire construction activity is clean, without much dust being raised. Also, modular building is economical. A single unit can be constructed for under $100,000, thus tremendously reducing the cost of the entire building.

There is a great scope for customization in modular buildings. Clients can have discussions with builders and custom design their own buildings with a great degree of flexibility. The height of the ceiling, thickness of the walls and other dimensions can be changed as needed. Modular buildings are also portable. Their units can be dismantled and relocated to other places if the need arises.

The modular technology was basically invented for single-room buildings such as kiosks, telephone booths, ticket counters, security outposts, etc. With a grand success in these buildings (today almost all single-room buildings are modular in design), the technology drifted towards larger buildings. Several factory buildings, offices, schools, supermarkets and even some residential buildings are modular. Some nations have put a restriction on new construction owing to increasing urbanization. For such nations, modular buildings are a solution, as they can be used to append to original buildings.

There are problems associated with modular buildings, too. Early modular buildings consisted of poorly welded ends, which gave rise to water leakage. Dampness may harbor mold and create unhygienic conditions in the room. Some modular buildings which do not provide good ventilation may cause headaches, dizziness and nausea. For this reason, modular buildings are considered by many to be a temporary housing solution, but not accepted for the long term. Despite several modifications by builders over early rudimentary patterns, there still exist reservations among a certain section of people on the use of modular buildings.