A transformational trend : off-site construction

Logistics

15/10/2024

Standardisation has long played a key role in the construction industry, where many components are manufactured to established standards. Now, forward-thinking architects are widely embracing the practice of off-site construction, transforming the conventional approach.

Originally intended for industrial facilities, prefabricated structures have broadened their appeal to a broad variety of buildings and applications – from simple retail spaces to the most complex projects. This transformation marks a major shift towards innovative construction methods that capitalise on the engineering and design excellence of prefabricated components.

The practice of off-site construction represents a new way of working on buildings, reflecting the industrialisation of construction. According to the 3^rd edition of the French annual survey of off-site construction, which covers French players in this sector, 44% of professionals surveyed claim to have adopted this method in 2023, up from 31% in 2022.

What’s off-site construction?

Off-site construction, also known as modular construction, is a process that involves prefabricating a building’s components in a plant before assembling them on the construction site. Each element, like the pieces of a jigsaw puzzle, is delivered to the site in an advanced state of completion, minimising construction times. This method uses a variety of materials, the most common being concrete, metal (steel structures) and wood (glulam for the structure).

Prefabrication is becoming the new standard on construction sites

GSE, a subsidiary of GOLDBECK, is a leader in the turnkey construction of commercial real estate and in the manufacture of steel and concrete components. Off-site construction, carried out in GOLDBECK plants, is an innovative, fast-growing approach. Unlike conventional on-site construction, it involves manufacturing modules in plants in Europe and assembling them on site, according to the group’s various activities in the industrial, residential, education and health sectors. This approach increases speed, quality and environmental performance, offering a sustainable and effective solution to the challenges facing the construction industry.

With this approach, design, detailing and manufacturing are carried out simultaneously, reducing in particular the overall duration of multistorey projects. Prefabricated components are ready for rapid on-site assembly, reducing construction time. Our multistorey buildings take about 12 months to build.

Of the 1,136 professionals surveyed, 90% said that the primary benefit of off-site construction was the reduction in construction times (up from 85% in 2022). In addition, 81% stated that this method also helps to reduce the environmental impact of construction. The growth potential of off-site construction is considerable, with an average annual increase of 25% to 30% worldwide. These figures testify to the strong interest in this approach.

Why go off-site?

Besides meeting your project’s technical and aesthetic requirements, the off-site approach offers great flexibility in terms of design and customisation. Our engineers and architects streamline the construction process by optimising the use of prefabricated elements. What’s more, thanks to Building Information Modeling (BIM) and our team’s expert advice, we can considerably improve the precision of execution and the efficiency of the works.

Off-site construction currently accounts for just 1% of the newbuild market in France. By comparison, the method is much more widespread in English-speaking countries, where it makes up 50% to 60% of newbuilds, depending on the asset category. In Scandinavian countries, the popularity of off-site construction is even higher.

However, the situation in France is set to change. The share of off-site construction is expected to reach at least 9% by 2031. This forecast illustrates the considerable interest and growth potential of this approach, which will play a much bigger role in the French construction industry.

Durable and sustainable?

To achieve our collective goals of urban densification and carbon reduction, we must ensure that our real estate developments are sustainable – including by building up rather than out. We need to improve the impacts of both the materials we use and our construction methods themselves. Off-site construction is an effective solution to help mitigate a project’s carbon footprint. By reducing the need to transport materials and labour, it limits greenhouse gas emissions. What’s more, prefabricated components are robust and durable, giving buildings a longer life cycle.

From the environmental perspective, our plants comply with the latest efficiency standards, with reduced energy consumption. What’s more, we are better able to optimise and recycle materials at the plant than on the construction site. Not least, off-site construction causes significantly less disturbance locally, to the community and the ecosystem. For example, noise pollution – and its impact on people and wildlife – is considerably reduced.

Integrating prefabricated elements into our projects

The increasing complexity of modern construction, combined with climate-related legislation, is pushing us to reduce our carbon footprint and optimise the use of our resources.

In this context, it is crucial to choose sustainable materials and to consider the building’s entire life cycle, over a period of 50 years. The Life Cycle Assessment (LCA) of our buildings enables us to measure the carbon footprint from the laying of the foundations to demolition. We systematically use low-carbon concrete in all our projects, which significantly reduces our buildings’ CO2 footprints.

We conduct in-depth studies to minimise the costs of each project. The use of standardised CEM III concrete is one way we rationalise expenditure for our clients. With the exception of the concrete slab, which is cast in place, the columns, walls, facades, staircases and other elements are prefabricated and inspected in our plants, substantially reducing the materials’ carbon footprint.

An innovative & sustainable off-site construction project in the port of Hamburg

For the purposes of a real estate development in the port of Hamburg, we were faced with a shortage of space, with only one plot of land available. To maximise the use of this land and accommodate several users (including Airbus, Picnic, Bechtle and JYSK), we proposed to build a flexible & efficient two-storey building, optimising space and logistics processes.

Despite the challenges posed by the polluted and unstable soil of the brownfield site, compounded by the complications of COVID-19 measures, we managed to meet the construction deadline by adopting off-site construction. This approach enabled us to prefabricate the components, considerably reducing construction time and minimising environmental impacts.

The innovative project comprises two buildings with a total surface area of 128,000 m² and a height of 25.15 metres. Certified BREEAM Excellent for its commitment to the environment, it stands out for its remarkable architectural features: a two-storey building with loading bays suitable for HGVs of up to 45 tonnes on the upper floor and offices on the mezzanine. A car park located between the ground floor and the upstairs lorry yard, accessible by a separate ramp, is built under the yard for cars. Two ramps ensure the smooth flow of traffic.

Both storage levels have a 10-metre clear height, with the concrete structure guaranteeing solidity and durability. In addition, a green belt on the façade, equipped with a watering system, adds an aesthetic touch and sustainable value to the property.

The project combines performance, functionality and sustainability to meet the most demanding requirements, while demonstrating the benefits of off-site construction in a complex and constraining context.