Sustainable construction system

HOW SUSTAINABLE?

Steel is arguably the most sustainable of the major structural materials. It has numerous sustainability benefits, which are guaranteed to be realised whenever steel is used.

They include: low waste, flexibility, offsite manufacture, speed, resource efficiency, adaptability, demountability, long lasting appeal, safety, reusability and recyclability.

These inherent characteristics result in many social, environmental and economic benefits to satisfy sustainability’s ‘triple bottom line’.

Steel is a fast, safe construction material. Reduced time on site means lower costs, quicker returns and less disruption to the local community.
Steel is manufactured offsite in a safe, factory environment and arrives on site when needed, making it predictable with no unpleasant surprises.
There is no site waste and any waste that is generated earlier in the process is easily returned to the steel supply chain. Steel treads lightly on the ground. It has high strength to weight ratio and is resource efficient. Fewer deliveries mean reduced emissions.

What is the carbon footprint of structural steel?
The CO² emitted during the production of one ton of plate steel is 920 kg, which can be reduced by 80% if sourced from reprocessed scrap steel. The average intensity of CO² emissions from total global cement production is 222 kg per ton of cement.

We have estimated that an equivalent structure made in concrete would have a ratio of 40:1 in terms of weight. Therefore our Yurt concept structure using an estimated 1.3 tonnes of steel would generate 1 ton of C0² during steel production, compared to 9 tonnes C0² if it was constructed in a concrete structure. That does not include the reduction from transport emissions.

Benefits to the Consumer?
There are many reasons why homeowners are turning to steel framing:
• High strength results in safer structures, less maintenance and slower aging of structure.
• Fire safety
• Not vulnerable to termites
• Not vulnerable to any type of fungi or organism, including mold.
• Less probability of foundation problems - less weight results in less movement.
• Less probability of damage in an earthquake.
• Lighter structure with stronger connections results in less seismic force.
• Less probability of damage in high winds.
• Stronger connections, screwed versus nailed.

 

Processes of the system

STEEL PROFILES FABRICATED USING A FORMING MACHINE

 

Cold-formed steel (CFS) members are made from structural quality sheet steel that are formed by roll forming the steel through a series of dies. No heat is required to form the shapes (unlike hot-rolled steel), and thus the name cold-formed steel.
Cold-formed steel members and other products are thinner, lighter, easier to produce, and typically cost less than their hot-rolled counterparts. A variety of steel thickness is available to meet a wide range of structural and non-structural applications.

EXAMPLES OF STEEL PROFILE

 

The individual steel profiles are cut to the exact size specified from the CAD drawings. The profiles are formed with additional curved edges to increase the rigidity of the profile without increasing the thickness of the steel.
All the holes are also precisely punched out so the profiles are easily fixed together, when being combined to assemble a component or panel.

EXAMPLES OF COMPONENT ASSEMBLY

 
 

Self-drilling, tapping screws are the most prevalent fasteners when constructing a component or panel. Other connection technologies, such as pneumatically driven fasteners, powder-actuated fasteners and crimping (fastenerless) can also be used.

 

Using traditional construction systems of building usually result in the amount of material waste generated being significant. During the Design stage any opportunities for using prefabricated building components are used where ever possible. Due to the industrial processes of prefabricating the waste can be minimized and would result in a higher accurate and quality finish.

EXAMPLES OF STRUCTURE

 

All structural members shall be aligned vertically (in-line framing) to transfer all loads to the foundation, unless horizontal load distribution members are specified. therefore the structural loads are spread throughout the wall sections.

People like a steel built environment, which is light, open, airy and adaptable. Steel structures mature with age, rather than deteriorate and decay. Steel’s long clear spans mean that interiors can be changed with ease. The longevity of a building is fundamental to its overall sustainability

Homeowners expect their homes to last for a lifetime or more. Therefore, it is critical that framing materials have the proper protection to provide this longevity. With steel, this protection comes in the form of galvanizing. Steel members located in an indoor atmosphere (such as wall and floor framing) have a very low rate of corrosion.
Studies showed that typical G40 zinc coated steels, in such an environment should last for more than 100 years. All structural-framing members have a minimum metallic coating of G60 (or equivalent). Non-structural framing members have a minimum metallic coating of G40 (or equivalent). It is essential not to install CFS joists in contact with copper. CFS members do not react with dry wood, drywall, insulation products, or dry plaster or mortar. In particularly severe climates, such as coastal, G90 coating should be specified for protected framing members, where corrosion, termites, earthquakes, typhoons and tsunamis are significant concerns.

 

 

CLADDING AND BUILDING SERVICES

Our fabrication processes use cladding to provide the thermal insulation characteristics to reduce energy consumption, whilst ensuring a robust wall to give security and longevity of the building. Out side finishes can be brick, stone or wood therefore identical aesthetic finished look when compared with a conventional construction system.

Can the benefit of thermal mass be realised with a steel framed building? The thermal mass of a building can be used to reduce the requirement for active heating and cooling. People instinctively associate the cool inside churches with their mass, but it has far more to do with the lack of windows and low solar gain along with an absence of heat generating electrical equipment and lighting.
Optimum thermal mass is generated from the first 100mm thickness of concrete floor slab, which is available in standard steel-framed construction. The extra mass associated with heavier weight structures is a waste, which is compounded by the larger foundations required.

Building services, Plumbing, drainage and electrical circuits are easily and quickly can be installed through the wall sections, using the ready punched out apertures during the forming process. As the edges of these apertures can be sharp Snap-in plastic insulators, grommets, conduits, or other approved wire protection methods should always be used, to protect the plastic sheathing on electrical cables and wires when passing through holes in CFS members.
Also it is important to ensure that copper pipes are always separated from the steel framing by using plastic insulators or other approved methods.

 

Production of the system

THE MOBILE FACTORY

 

All that is required to construct the building structure is to be supply roles of thin gauge steel (usually in 500 meter lengths) and boxes of fixing components. One of our concept Yurts use only one role of steel, therefore one transport container can provide steel for twenty Yurt buildings.

Manufacture of the structural components on site can reduce significantly the cost and risk to a construction program, especially when the site is located in a developing country where logistics can be an issue.

The size of the factory can be scaled by the number of units required to be constructed at one time. The logistics of the construction program will indicate to us how many containers are required to be on site.

 

Our thoughts on new urbanisations

We have made a study into the possibility of creating sustainable urbanisations in Angola using our construction system, which until recently has had significant yearly economic growth, therefore have an urgent need to create new urbanisations.

Due to the limit of resources that our planet Earth have to offer, the development of countries like Angola, cannot copy the ‘20th Century’ Centralised model, of the so called Developed countries…….This error is already being replicated, which of course is a slow recipe of disaster for all of us.

We hope that sufficient funding and policies will be made available for Sustainable Development of the growing economies, designated from the Copenhagen Summit.