Choosing a safe, yet cost-effective building solution for your next construction project might seem like a daunting task. Relying on age-old methods might often feel like the safer, easier, and least risky option. Only when you familiarise yourself with proven new and innovative solutions, do you realise the benefits of an alternative, energy-efficient building solution. There undoubtedly is no real comparison between conventional vs new building methods.
How pre-engineered, modular and hybrid steel buildings differ from conventional buildings
Unlike brick and mortar, these alternatives have evolved with technology to become the new future. It allows the chained construction process to continue, even if one link in the chain gets delayed.
Previously if the foundations were not laid the roof could not be installed, rainy days meant little to no progress on site. But not anymore. With modular hybrid steel buildings this is no longer the case. Modular hybrid steel buildings is a steel building where the designer makes use of a combination of heavy welded or hot rolled steel members in combination with light steel frame sections to develop a cost-effective modular
construction solution to clients.
The components of pre-engineered buildings and modular buildings are manufactured off site in a controlled factory setup and delivered to site. Units are assembled by clicking and bolting pre-drilled and numbered parts together. Not only does this simplify site logistics with a reduction in workforce and equipment but also reduces safety risks and improves quality control.
Who is currently using these new building methods?
An example of a recent local project that was built using modular construction technology, is the Hi Monte hotel at Montecasino in Fourways, South Africa. Built within just eight months, it consists of 130 modular units and several facades. Most of these unitised facades were completed in a controlled factory environment, therefore drastically reducing scaffolding requirements on site, and increasing quality and accuracy. Their comparison between conventional vs new building methods benefitted the project in many ways.
Other suitable applications include modular residential apartments, multi-story buildings of up to 25 storeys, eco-friendly houses, residential buildings and construction camps.
Another example is the world’s largest beer brewer. They welcomed the benefits of PEB structures after a need arose to increase the overall supply capacity of its Rosslyn plant in Pretoria, South Africa. Tight project deadlines resulted in the team looking to more innovative ways to construct a building in a shorter period of time and at a reduced cost.
This led to a new, pre-engineered 13 000m2 pack line and PRM warehouse.
When compared to the estimated cost for a conventionally designed building, using a PEB resulted in an approximate 30% cost saving on the structural steel and sheeting. Furthermore, it ensured reduced turnaround time as the full project spectrum (design to fabrication) had a single source responsibility that was executed by professional engineers.
The national COVID-19 lockdown was implemented during this projects’ fabrication stage. Even then, technological advancements allowed the JTC Building Systems team to remotely continue with the design and detailing of the rest of the project during lockdown, ensuring that fabrication could commence once it was allowed.
A building with unique, technical design features
The PEB structure at the Rosslyn plant was designed to withstand an unfactored uniformly distributed load of 1 kPa. Rafters and columns are spaced at 12m centres, instead of more conventional 6- to 8 meters spacing, therefore reducing the time required to construct foundations.
Purlins were designed from 350 MPa material, rather than conventional 200-230 MPa material. This ensured that purlins could withstand induced loads, while spanning 12m. Mezzanine floors cantilever for 3m from main columns, reducing columns and obstacles in new pack line.
PEB structures tend to also be more stable during erection when compared to conventional buildings from trusses. This increases the rate at which steel can be erected, reducing construction time as well as preliminary and general costs on the project.