Structural Design
Light-Gauge Steel Building Design
Using cold-formed galvanized sections, we prepare the structural design for the building permit and the fabrication drawings the workshop will produce from, for houses, added stories, roof stories and offices.
What is light-gauge steel construction, and where is it used?
The load-bearing members of a light-gauge steel building are C, U and omega sections made by cold-bending thin galvanized sheet. Because the wall is thin, the section gives high strength for its own weight, but for the same reason it is sensitive to buckling, and most of the calculation effort goes into buckling checks. With less total mass in the building, both the earthquake force and the load reaching the foundation go down. The sections are cut and punched to size in the workshop and joined on site with screws or rivets.
We design light-gauge steel for detached houses, stories and roof stories added to existing buildings, steel roofs sitting on reinforced concrete buildings, and site or prefabricated office buildings. Structures on top of containers and shelters that have to be put up quickly after a disaster can also be built with this system. In Gölcük and across Kocaeli, the people who ask about it most are owners who want to gain usable space on a building that went through the 1999 Kocaeli earthquake without adding much mass to it. Contractors who need a short delivery time ask too.
Our work is the design. We set out the structural system, calculate the sections and connections, clear clashes with the architectural and building services designs, and draw the structural design for the permit and the fabrication drawings. We choose the sections from the sizes that the manufacturer's profile line can produce. If you also want us to build it, the work moves under Construction and Contracting.
Scope
Structural system selection
We choose between a panel system, where the walls carry the load, and a column-and-beam frame by looking at the spans and what the manufacturer can produce. Plans that need wide, open space favor the frame.
Section and member calculations
We check studs, beams, purlins and trusses separately for local, distortional and global buckling. In a thin-walled section, one of these usually sets the limit.
Connection and anchorage details
We calculate and detail screwed, riveted and bolted connections, bracing and the connections to the foundation. In a panel system we calculate separately the anchors that carry the tension at the ends of shear walls down to the foundation.
Added stories and roof stories
We look at the structural system of the building underneath first. We show by calculation the load of the new story and its effect on the existing structure, and if the building cannot take that load, we say so plainly in the report.
Insulation, fire and sound coordination
We build up the wall and floor layers together with the architect. Since the steel section creates a thermal bridge, the position of the insulation, the board layers needed for fire resistance and sound transmission are decided at this stage.
Fabrication drawings
We draw the panel layouts, section cutting lists and assembly sequence in a form the workshop can put straight into production.
Applicable regulations and standards
We carry out the seismic analysis to the Turkish Building Earthquake Code (TBDY 2018). We take the general rules of steel design from the 2016 regulation on steel structures and the strength calculation of thin-walled cold-formed members from TS EN 1993-1-3; for load values we use TS 498. The fire resistance periods required for walls and floors come from the fire protection regulation. The number of stories, building height and setbacks are set by the zoning plan and the related regulations. A light-gauge steel building, like any other, is subject to a building permit and building inspection.
How we work
Preliminary evaluation
We review the information on the plot or the existing building, the zoning status, the draft architectural design and the geotechnical investigation report. If we see that light-gauge steel does not suit the job, we say so at this stage.
System layout
Together with the architect we decide on a panel or frame system, the stud spacing and which walls carry the load down to the foundation.
Analysis and sizing
We build the model in commonly used structural analysis software and size the sections and connections under gravity, wind, snow and seismic effects.
Design and approval
We prepare the structural design and calculation report in the form required for submission to the municipality. We work in the corrections from the municipality or the building inspection firm and resubmit the design.
Fabrication and erection support
We give the shop drawings to the manufacturer. If something on site does not match the drawings during erection, we answer the questions and revise the detail if needed.
Deliverables
- Structural calculation report (load analysis, seismic analysis, member and connection checks)
- Foundation and anchorage design
- Floor plans, panel layouts and sections
- Connection and joint detail sheets
- Section cutting lists and material lists
- For added-story projects, an assessment report on the existing structure
Frequently asked questions
Does a light-gauge steel building need a permit?
Yes. Light-gauge steel buildings that are permanent structures are subject to a building permit. The architectural, structural and building services designs are submitted to the municipality, and the building inspection firm supervises construction.
Can a light-gauge steel story be added on top of my existing building?
Yes, if the existing structural system can take the extra load and the zoning status allows it. We do not say this without seeing the building; we first check the building's seismic performance by calculation and only then move on to the added-story design.
Up to how many stories can light-gauge steel be used?
There is no single answer. Light-gauge steel is mostly used in low-rise buildings; how many stories a given project can reach is decided by the zoning conditions, the use of the building and the seismic analysis together.
How are fire protection and sound insulation achieved?
The sections are lined with fire-resistant boards, and the cavity between them is filled with an infill such as mineral wool. We decide with the architect how many layers of board are needed, based on the fire resistance period the relevant regulation requires for that building.
Do you also carry out the construction?
Yes, if you want. The service on this page is design; we take on fabrication and erection separately under Construction and Contracting.
Examples from practice
Our projects in this field
Request a quote for your project
Write to us with the type of building, its location and the documents you have. We will agree the scope and timeline with you and send a written quote.