Just-in-time construction with a steel frame: delivery of 4 near-zero energy homes

Steel frame construction for project developers, the rapid construction of near-zero energy homes. Article by Cluster Building Industrialisation

Anyone wanting to increase the ecological profile of their new construction or renovation usually thinks of wood. However, this is not the only option. Steel frame constructions also score extremely well in terms of sustainability. Moreover, they offer rapid construction time and there is little to no limit on the architectural freedom. Although this construction technique is still little known in Belgium, some pioneers have already taken the plunge. For example, a project developer who deliberately chose beSteel’s FastWall for the construction of four terraced houses in Thuin.

The rue des Merles in Thuin is a small street in the middle of a quiet residential area. The project developer decided to purchase the last vacant lot to build four terraced houses. “Rapid return on investment is crucial in such projects”, explains Xavier Vromman, manager of Meta-System. “It is therefore not surprising that the client set a short construction time. He also strived for maximum durability. Not only did the houses have to be energy efficient. He also wanted to use cradle-to-cradle building materials. These two requirements led him to choose the steel frame and FastWall solution from beSteel in which all the external and internal walls and roof are prefabricated off-site.”

Construction with three workers

The FastWall provides the steel frame construction elements with structural cladding on one side. “In the meantime, we are going one step further”, says beSteel business development manager Julie de Troostembergh. With FastWall, we can supply completely closed and finished walls, including windows, doors and wall coverings. So there are a number of options: from cold-rolled profiles that have been machined with a tolerance that can be measured to the millimetre, to 3D units and custom closed walls.” Xavier Vromman continues: “The regular version also offers many advantages. In this case, the shell was completed in five days. The outer walls were each constructed with two large panels, one per floor. In order to guarantee optimal acoustics and fire safety, each house was built separately. The beSteel solutions were especially interesting because of the user guide and assistance the manufacturer provides. We get a detailed description of how and in what order to assemble the steel frame panels.

There is not much manpower involved. Three people were enough for this project: one person to operate the crane, and two to install the panels.”

Strong feather-weight

Building with the beSteel FastWall offers even more advantages. First and foremost, there is the light weight of the steel frame, which can save on foundation costs. “This opens up many options for increasing the height of houses and apartment buildings”, explains Julie de Troostembergh. “It is often possible to build more floors on the existing foundation. Despite the light weight, they are very strong constructions. Six to seven construction levels are easily achievable with a steel frame. Because all our panels are load-bearing, it is possible to achieve large spans. And architects can also indulge themselves in other areas. After all, steel frame is easy to process, which makes it possible to explore a wide range of creative ideas.

Even more advantages

The options for wall finish are also comprehensive. After covering the structural panel with thermal insulation, the choice of façade finish is completely free: with options including crepi, stone strips, wood or even traditional masonry, such as in Thuin. Xavier Vromman: “One of the greatest assets is the enormous precision of the construction. The tolerances are down to the millimetre. We get the exact dimensions for windows, joinery, wall cladding, roofing, etc. even before the panels go into production. This enables us to arrange just-in-time planning with our suppliers and subcontractors. The result is indirect benefits: waiting times, storage costs, storage space and damage are no longer an issue.”

Standardisation results in fast delivery

The design of a steel frame construction is an art in itself. This is why beSteel always thoroughly scrutinises architects’ plans. “Our internal engineering office will go through the stability calculations thoroughly”, says Julie de Troostembergh. “We then draw the whole thing in 3D. The whole production process then runs fully automatically. Each part is given a unique code so our technicians can assemble the panels flawlessly and quickly. Because we work according to a standardised method, we can respond extremely quickly to any order. Delivery within four weeks after placing an order is no exception. Even for projects designed by the architect as an ordinary brick construction, such as in Thuin.”

Steel frame is the future

In Thuin, working with a steel frame was slightly cheaper than using the traditional construction process. “This was due to the fact that the four units are identical except for the dimensions of a few windows”, explains Julie de Troostembergh. “The stability calculation and the drawing of one house was sufficient, after that it was pure copy work. For larger complexes, this can result in a significant financial benefit. However, the real gain is in the reduction of construction time while ensuring greater quality and durability. We are therefore convinced that steel frame construction will soon be the norm in our regions rather than the exception.”