Modular construction 101: here’s how it’s making buildings sustainable
Posted on: 23 April, 2025
Modular construction isn’t just another design fad – it’s a growing trend with huge potential to help us realise a sustainable built environment.
The impact of the built environment on greenhouse gas emissions is well documented, with our sector responsible for around 25% of the UK’s annual emissions. What’s more, the construction industry produced over 10 million metric tons of carbon dioxide in 2021, which accounted for 2.4% of the total UK carbon emissions for that year.
Yet the demand for new buildings isn’t slowing down. By 2060, the global building floor area is expected to double, and ten years before that, the energy demand from the built environment may have grown by another 50%.
Unsurprisingly, work is being done to look for new alternatives to the traditional building lifecycle and implement new, sustainable processes. One such process that may hold a lot of promise for helping realise a sustainable built environment is modular construction.
What is modular construction?
Modular construction is where buildings are made of repeated and standardised sections, known as ‘modules’. While it is technically a form of prefabrication, this modern method of construction focuses on the offsite construction of large and repeated sections, whereas prefabrication is reserved for specific components and materials.
As with prefabricated buildings, modules are constructed in an off-site factory setting under controlled conditions, away from the site of the project itself. In this type of construction, the vast majority of the work is completed here before the modules are transported to the site for assembly, with all work still conforming to modern building codes, regulations and standards.
Learn more: A guide to prefabrication (and how it’s transforming construction)
Modular buildings are a fast-growing market. Imports of prefabricated structures or modular units have doubled in the UK since 2019. A 2021 report by Savills found that 10% of new homes being built involve modular construction methods, while the US market for this sector is expected to grow to as much as US$271billion by the end of the decade.
The 4 types of modular construction
Temporary modular construction
This modular construction method focuses on building relocatable structures that can be transported with ease. It’s often used in the tourism and hospitality sectors, due to its flexibility.
Permanent modular construction
Unlike temporary modular construction, permanent modular construction focuses on modules and components that are to be used in the long-term.
Relocatable buildings
This form of temporary modular construction focuses on the production of entire buildings that can subsequently be relocated.
Volumetric modular construction
Volumetric construction focuses on the production of large and enclosed modules.
8 benefits of modular construction
1. Greater sustainability
Modular structures offer significant opportunities for improved sustainability. As the market for modular construction projects grows, specialist builders are utilising sustainable construction methods to reduce the embodied carbon of the materials used. Many companies are also focusing on energy-efficient building design practices when constructing modular units.
Learn more: What is embodied carbon (and what can we do about it)?
2. Reduces material waste
Factories that construct modules are often more controlled environments than those on-site. This allows them to both better ensure quality of building components and individual modules and, most importantly, reduce the amount of wastage created in production.
3. Potential for reuse
The modular construction process is designed with recycling in mind. Modular structures have high potential for reuse and repurposing as they’re often portable, versatile and flexible by nature. This is another win for sustainability, as businesses and construction companies have the option to reuse existing modular buildings instead of creating new ones and producing more carbon emissions.
Learn more: What is adaptive reuse (and how can it create a sustainable built environment)?
4. Time savings
Perhaps the most immediate benefit modular construction for businesses over traditional methods is the acceleration of production and construction times. Modular projects can be completed 30-50% faster, owing to their standardised and repeated design and the fact their production takes place off the construction site, meaning it doesn’t clash or interfere with other processes.
5. Cost-effectiveness
As modular buildings are oriented around repeated designs, the cost of producing these can often be cheaper than having pieces built separately, as with conventional construction practices. What’s more, as these projects have a faster turnaround time, they reduce the number of working hours required and, subsequently, labour and construction costs. And, with a lack of skilled personnel a key challenge for companies (more so than even rising building material costs), this could be a particularly important benefit for the built environment.
Learn more: All buildings great and small: the spectacular rise of tiny homes
6. Aesthetic and design opportunities
Along with being practical and efficient, modular buildings hold possibilities for more attractive and eye-catching design.
The Nakagin Capsule Tower in Tokyo, Japan (pictured) is perhaps one of the most famous examples of modular design, dating back to 1972, and while it is now no longer standing, many of its component units have been successfully repurposed.
7. Protection from weather
As with prefabricated construction, modular components that are built in manufacturing facility rather than on the building site are protected from the weather. This offsite construction method ensures greater quality control and preventing delays or potential issues with assembly.
Learn more: Building climate resilience into the built environment
8. Improved health and safety
Protection from weather won’t just benefit the final product – it will keep workers safe, too. Shorter turnaround times decrease the risk of adverse weather and, subsequently, injuries to staff.
The potential drawbacks of modular construction
It’s important to note that modular construction isn’t without its potential drawbacks and challenges.
Less variety
The use of repetition in the design phase of modular construction will likely be appealing to many, but it can pose challenges from an architectural standpoint. Modular construction works best when modules are produced at scale, which naturally means businesses will be left with limited variety, as attempts to differentiate them defeat the benefits of this approach in the first place.
Transportation costs
Like prefabricated buildings, there are cost savings when it comes to offsite construction, but transportation can still pose a financial headache. This is especially true of modular construction, which are even more at the mercy of traffic, height restrictions and road widths, owing to their large size.
Less customisation for specific requirements
It’s not just from an architectural standpoint that modular homes and buildings present limitations. With less room for customisation, design teams will struggle to modify designs and proposals for specific needs, contexts or users.
Historical perceptions of performance
While significant strides have been made in the performance of modular buildings, they still carry a poor reputation in comparison to permanent structures. This outdated view can put off many construction companies from implementing this technique, despite the benefits it can offer.
Investment costs
The technology and expertise required to utilise modular principles remain expensive and prohibitive for many companies. While they’re simple to assemble, their designs are intricate and they’re not easy to manufacture. In some cases, creating modules also requires the use of computer-aided design and 3D printing, adding to the costs and reducing the perceived return on investment.
Final thoughts
The modular approach is more than just another trend – it’s an innovative and sustainable alternative to traditional construction methods that could go a long way to addressing our sector’s impact on the ongoing climate crisis. If businesses can make it work for their construction projects, they will experience a raft of other operational benefits.
What’s more, it could play a crucial role in addressing global housing shortages. The UK government has moved to support this developing area in recent years, from investing Ilke Homes’ Yorkshire-based modular building factor in 2019 to providing funding for affordable housing built from the modern methods of construction.
However, recent events have shown a strategic approach to implementing methods like modular construction is needed in the industry. In a letter to the then Secretary of State for Levelling Up, Housing and Communities, Michael Gove, Lord Moylan, chair of an inquiry led by the House of Lords’ Built Environment Committee, wrote:
‘Moderns methods of construction are successfully used to construct homes abroad and to build high-rise and non-residential buildings in the UK, but this success has thus far eluded the building of MMC homes in meaningful numbers.
‘In the context of an ageing skilled workforce and the need for greater building sustainability, MMC has shown some promise. We heard evidence that the government couldn’t achieve its housebuilding targets without a sizeable contribution from the MMC sector.’
Sustainability isn’t a passing trend – it’s here to stay and is constantly evolving. If you want to inspire and action change in your career, UCEM’s MSc Innovation in Sustainable Built Environments will give you the skills you need, both now and in the future.
Find out more: MSc Innovation in Sustainable Built Environments – University College of Estate Management
