Primer Modular buildings are buildings that are built in a factory and then transported to a site for assembly.
This type of modular construction has been a method of building for decades, but recently it has gained momentum as the scope of modular construction is being used for all types of construction, from offices and hospitality buildings, to residential homes, and much more.
How Are Modular Building Built?
Modular buildings are built in their entirety or modular subassemblies at a manufacturing facility, away from building sites; then transported to the intended location and turned into the final building.
Overall a significant portion of the work, 60%-90% of the work, is done in a factory-controlled environment.
By constructing in a factory setting, contractors can utilize lean manufacturing techniques to create prefabricated modules.
There are different types of modular buildings, which can be put end-to-end or stacked, depending on which will create the spatial design configuration of the building.
Once the modules arrive on-site, they are tied together with the modular construction process using inter-module connections (or inter-connections).
Permanent modular buildings (for example, prefabricated homes), are built to the same (or sometimes more than) standards of traditional site-built properties, and they have high levels of quality control.
Permanent modular construction (PMC) provides a seamless opportunity to construct permanent buildings using multiple building types (for example, concrete, steel, or wood) and integrating subsystems such as windows, service connections, electrical service, plumbing and sewage connections, telecommunications connectors, air conditioning, and more.
Most of these added features can be fitted out before arriving on site, thereby saving on precious construction time further down the construction process.
These PMC structures are designed to remain in one position after they are built and have a virtually unlimited number of storeys to the extent allowed by building regulations.
The design stage is paramount to developing modular buildings. Design for Manufacture and Assembly (DfMA) practices need to be adopted to ensure assembly tolerances are controlled and provision is made for taking up any slack or misalignment.
CAD systems, additive manufacture (3D printing) and manufacture control systems are the basis for modular construction, since they do not offer the opportunity for onsite realignment.
Types of Modular Building
Modular buildings typically fit into one of two categories – permanent or temporary. Within those categories actual buildings can be anything from ‘flat-pack’ solutions to façade systems and those that are substantially complete offsite and then delivered and assembled.
What is Modular Construction?
Modular construction is a process where part of a building is constructed off site in a controlled plant condition and delivered and assembled to the final site location. Modular construction can encompass a variety of building types and floor plans.
When was Modular Construction Invented?
The first documented case of modular construction was in the 1830’s when a London-based carpenter, John Manning, made what was essentially a prefabricated home for his son. The home was made in pieces and shipped from England to Australia to be assembled.
This way of building also became quite popular in the United States during the California Gold Rush of the 1840s, used to construct the ‘Crystal Palace for Britain’s Great Exhibition of 1851, and once more popularized made possible by the prefab interval of World War Two and building around that period to quickly replace homes after the war.
The popularity of modular construction in the USA is currently so highly regarded that it led to the formation of the Modular Building Institute.
what are modular units?
Modular units are the sections that join up to become a prefabricated building or house. The number of units depends on size and level of finished product and style.
How Much do Modular Building Cost?
The price varies by the project scale and type of materials used.
Other aspects, for example whether or not internal fittings and fixtures are included, can considerably affect the construction costs of a modular building.
Case studies have shown that modular construction can provide substantial cost savings in direct comparison to traditional industrial construction.
Modular construction has successfully been used to save time and costs on projects, for example, weather has not been an obstacle delaying projects and projects can get underway even though a site is under development, which has further reduced the construction lead-time to completion from the start of construction to actually finishing a project.
How Long do Modular Building Last?
How long does modular building last? This depends on if the modular was designed to be temporary or permanent.
But while many people still think of modular buildings as temporary buildings, modern modular buildings can be built to last just like a traditional build.
PMCs have building regulations to adhere to that meet or exceed the same standards of building practice as traditional builds, many are constructed from the same materials as conventional buildings.
Modular buildings will have tests to satisfy quality (and safety), but just like the construction methods the buildings will need maintenance just like any other ”build” to keep them good and to sustain their life.
Considering all of this, modular buildings can be used for decades, and many prefabricated buildings built just after the Second World War are still in use today.
What is Volumetric Modular Construction?
Volumetric modular construction is where as much of the ”building” is done off-site as possible. This could mean that the bathrooms fittings are placed before the room goes on site, and tied into the rest of the modular structure.
This model of construction is where the internal finishes are radically constructed offsite, in factory conditions, this has the benefit of either removing the need to employ trades people on the construction site itself.
So it not only improves health and safety i.e. reducing people on site, but can also significantly reduce the on site ”time” taken to complete your build.
Benefits of Modular Construction Compared to Traditional Construction
Modular construction has numerous benefits over traditional construction methods.
Here are some of the positives of modular builds:
- Delays due to weather causes and other onsite issues are a non-issue with factory manufacture, eliminating many of the forthcoming potential delays to project completion dates.
- Factory conditions also provide a better quality product with better working procedures and better monitoring. Also, factory workers can work in a more pleasant and comfortable environment. It is also easier to work 24/7 in a factory to complete a project.
- Supplies are more easily controlled in a factory environment, reducing wastage and thus reducing cost, and reducing environmental impact when building. Believe WRAP UK, this could correspond to up to 90% reductions in total material used when compared to traditional builds.
- The manufacture of the modules can be started prior to the on-site processes having completed, such as the building of the foundations, and totally speed up the overall build.
- Modular construction allows concurrent construction of various parts of the building, thus it takes less time to complete the overall project.
- Modular construction is perfect for remote locations when on-site building could be challenging or costly. Creating the build in a less remote environment allows staff to work in locations with more readily available medical and sanitary provision if needed.
- There is potential for modular structures to be added to in the future, or even escape being treated as a relocatable building and benefit from refurbishment to achieve a new outcome.
- Due to meeting requirements for travel and assembly, the completed product is likely to be more durable than traditional builds that have not been assessed piece by piece.
- Many modular units are built using Structural Insulated Panels that add another layer of improvement, where they are light, yet durable, provide better thermal insulation and moisture and cold resistance compared with materials such as timber. Factory also gets rid of the potential of transferring excessive moisture within the construction, increasing the overall quality.
- A minimum time saving of over 50% has been reported in modular construction compared to traditional builds, not to mention the cost savings associated.
Disadvantages Modular Building
There are some challenges that come with modular builds, these challenges include:
- The transportation of the finished modular building sections can require a significant amount of space.
- Restrictions on manufacture and transportation can restrict the practical size of each modular unit, which can limit room size.
Applications
Where modular building used to be associated with temporary structures, along with improved quality, design and size of units mean this kind of construction continues to have new applications.
From offices, homes and in some instances even larger builds like sports halls, modular construction applications are expanding all the time.
No longer associated with small, low-cost structures, the new breed of modular buildings are showing that they offer possibilities for so many different applications while providing time and cost savings, with a comparable finish and quality as a traditional structure.