The main difference between a modular and a prefab home is that modular is a very specific type of prefab construction while prefab is a more generic term that refers to all prefabricated construction methods. Since at least 70% of the construction of a modular house takes place off-site, modular homes are considered a type of prefab. There are 4 main different types of prefab houses in the UK and Europe. While they all include some prefabrication in their building process, there are some big differences among them.
Main differences between the 4 types of prefab:
• Construction process
• Building regulations and laws
• Construction cost
By understanding the differences between modular and other prefab homes we can get an idea of the benefits offered by each type of prefab house, which is a good starting point when deciding which type of prefab building is best for us.
What is a Prefab Home?
Prefab homes are houses that are built using prefabrication techniques. There are different types of prefab houses, some are entirely built in an off-site factory while others are raised on-site with manufactured components.
Modular homes are houses built as a combination of one or more three-dimensional units called modules. These volumetric modules are entirely built in a factory and transported to the building site where they are set up in a fast and easy way.
Every module is built as a self-sustaining structure that includes every necessary element: electrical wiring, plumbing, finishing materials and fixtures. Since the prefabrication of the modules is so complete, the on-site works are highly simplified and once the modules are assembled on site the modular house is ready to be occupied.
Panellised homes are raised by putting prefabricated walls, roofs and ceilings together. These are known as panels and are constructed as complete systems that include everything from the interior wall to the exterior siding.
Common elements such as wiring, plumbing and thermal insulation are already incorporated into the panels. Therefore, even if panels are two-dimensional components of the house, once assembled, the panel built house looks like a complete building ready to be lived in.
Prefabricated log homes are the modern version of the traditional log cabin, a construction with a unique appearance characterised by walls that are built from logs laid horizontally. While the modern log house maintains the structural essence of this construction, it is built following quite a different building process.
A log house can be assembled on-site but in most cases it is raised up to completion in a factory to be delivered as a finished home.
Tiny homes are quite a new type of prefab that is generally designed to be on wheels. Originally, their small size was the consequence of building a house that can be transported by road, though it has become the identity of this type of construction.
Tiny houses are such a popular housing solution that we can talk about the tiny home movement. Affordability is one of the most attractive aspects of these houses, though tags such as minimalism, freedom and a simple life are already inseparable to these constructions.
What’s the Difference Between Modular and other Prefab Homes?
Every type of prefab applies modern building techniques by mechanising part of the construction and even if that translates into prefabrication for all of them, it looks highly different from one to another.
All prefabricated housing options are built either entirely or partially off-site in a factory-like environment. However, the construction process highly differs from one prefab type to another and one of the biggest differences remains in the kind of product that is prefabricated:
The prefabrication stage of a modular construction produces three-dimensional modules that once put together will form the overall house.
After the manufacturing process of a panel built house is completed, the delivery resembles a giant puzzle and every piece will have to be put together to create the house.
Tiny houses, as well as most log homes, are 100% prefabricated and as soon as they leave the manufacturing plant, they are completed and ready to be lived in.
Building Regulations and laws
All houses being built in the UK and Europe are required to be constructed according to the building codes in order to ensure the safety of its occupants. These are a set of regulations that differ from one location to another depending on the specific needs of every town, city or country. Modular, panel built and log houses are all built in consonance with the building codes. Tiny homes though are built quite differently since they are not legally classified as permanent houses but as caravans. However, this classification does not exempt them from following a set of codes since caravans have their own set of building regulations.
This classification difference dictates the legal requirements concerning the location where the house is placed. All permanent fixtures -modular, panellised and log houses- are required to obtain planning permission in order to be set on one plot. Though tiny homes, being considered caravans, in most cases can be placed in the back garden and moved from one place to another without planning permission.
The price difference between one prefab and another can be considerable. Modular, panellised and log houses are the most expensive of the group while tiny homes are the cheapest. Still, all types of prefabricated houses are generally more affordable than those built with traditional construction and can save as much as 20% of the overall construction cost. Prefab construction saves money because building off-site enables a construction process that is highly mechanised reducing construction time and manual workmanship which reduces the overall building cost.
Those prefabs with a higher percentage of manufacturing in the overall construction process are generally more affordable. Therefore, modular buildings are usually more affordable than panellised ones. Tiny homes, however, can offer a cost that is even more reduced since they save extra on the cost of land given that they don’t require any definite location or on-site work.
Is modular better than other prefabs?
All types of prefabricated homes can make a great house and modular isn’t necessarily better than other prefab housing options. However, since the differences between different prefabs are considerable, it is important to identify your needs and possibilities to choose the one that best suits your situation:
- You are looking for a fast and easy-to-build house: Modular homes follow some of the easiest construction processes since the prefabricated works take as much as 80% of the overall process and the on-site works required after assembly are minimal.
- You live in a remote area with difficult access: The priority, in this case, is to choose a prefab method that can be easily transportable. Since the prefabricated panel construction systems are easier to transport than three-dimensional modules, a panel-built house is generally a better option.
- You want a traditional look: Log houses offer the beauty of a traditional appearance with the benefits of modern construction methods. Since both the logs and the structure of the house are prefabricated, this building is raised fast and at an affordable cost even though it offers a classic look.
- You value the freedom of mobility: If you are looking for a type of house that could be moved to another location, your choice is a tiny home since these types of houses are built on wheels instead of foundations.
Is modular the same as prefab?
A modular home can be referred to as a prefab home, though a prefab home isn’t always a modular building.
Are prefab homes worth it?
Definitely. Prefabricated construction is a modern way of building that is faster, cheaper, and more sustainable than traditional construction.
Is prefab cheaper than building?
Yes, factory-built homes are cheaper than traditional construction and can save as much as 20% of the construction cost.
 De’Ath, Farmer, M. Build homes, build jobs, build innovation: A blueprint for a housing led industrial strategy. HTA Designs https://www.hta.co.uk/storage/app/media/build-homes-build-jobs-build-innovation.pdf
 The Building Regulations 1991: caravans and mobile home GOV.UK https://www.gov.uk/government/publications/the-building-regulations-1991-caravans-and-mobile-homes
 Bertram, N., Fuchs, S., Mischke, J., Palter, R., Strube, G., & Woetzel, J. (2019, June) Modular construction from projects to products Capital Projects & Infrastructure https://www.ivvd.nl/wp-content/uploads/2019/12/Modular-construction-from-projects-to-products-full-report-NEW.pdf
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