--- url: https://qsteelcad.com/en/turkey-light-steel-regulation-2027 language: en alternate: https://qsteelcad.com/hafif-celik-yonetmeligi updated: 2026-11-06 publisher: RENMAE Teknoloji ve Yazılım LTD. ŞTİ. --- # Turkey Light Steel Regulation 2027 Guide The Regulation on the Design, Calculation and Construction Principles of Light Steel Buildings comes into force on 1 January 2027. We read the text section by section, compared it with the Turkish Building Earthquake Code 2018 (TBDY 2018) and turned it into tools that manufacturers, engineers and contractors can use. > This page is an independent guide prepared by RENMAE. It is not the official text and does not replace legal or engineering advice. The binding text is the one published in the Official Gazette. ## Short answer The Regulation on the Design, Calculation and Construction Principles of Light Steel Buildings was published in Official Gazette No. 33256 of 17 May 2026 and comes into force on 1 January 2027. It covers prefabricated, hybrid, modular and on-site light steel buildings. In seismic design it applies in addition to the TBDY rules. - **Published:** 17 May 2026 - **Official Gazette:** No. 33256 - **In force:** 1 January 2027 - **Annex:** 13 sections, 125 pages ## The regulation in two minutes - **Wider scope:** Prefabricated, hybrid, modular and on-site profile buildings in a single text. - **Higher material limit:** Minimum yield 250 MPa. DX51D to DX57D are not used in load-bearing studs. - **Thicker studs:** At least 0.9 mm for load-bearing studs; it was 0.8 mm in TBDY 2018. - **Tied to galvanizing:** At least 180 g/m² in 41 provinces and at least 275 g/m² in 40. - **A clear rule for bracing:** Bracing is one continuous member between the top and bottom track. - **Smaller holes:** The circular hole diameter/web ratio dropped from 0.70 to 0.40. - **Fire and modular added:** Fire design, modular and hybrid systems have their own sections. - **A site checklist:** Temporary stability rules and an 8-heading checklist entered the text. ## Differences between TBDY 2018 and the new regulation The table is our own comparison of the two texts and shows the main differences. An article that is not listed here has not necessarily stayed the same. | Topic | TBDY 2018 Chapter 10 | 2027 regulation annex | Article | | --- | --- | --- | --- | | Design method | ASD (GKT) or LRFD (YDKT) | LRFD (YDKT) | Section 4.2 | | Minimum yield stress | 235 MPa | 250 MPa; 220 MPa allowed for purlins, façade girts and non-load-bearing studs | Section 2 | | Wall thickness range | 0.45 to 16 mm | 0.45 to 4 mm | Section 2 | | DX51D to DX57D | No separate ban | Not used in load-bearing studs | Section 2 | | Load-bearing stud wall thickness | At least 0.8 mm | At least 0.9 mm | Section 6 | | Steel-sheet sheathed panel | 10.2.1.1 mentions OSB and plywood | Among High Ductility Level systems | Section 3 | | Buildings above 10.5 m | No separate ratio | Demand/capacity in studs at most 0.90 | Section 6 | | Bracing layout | Figure 10.2 example layouts | One continuous member between top and bottom track | Section 6 | | Circular hole / web | < 0.70 | < 0.40 | Section 10.1 | | Between holes, centre to centre | At most 600 mm | At least 600 mm | Section 10.1 | | Galvanizing | Reference to a standard | At least 180 or 275 g/m² according to Annex 1 | Annex 1 | | Wind lower limit | Not in the text | Basic speed 28 m/s, characteristic load not less than 0.5 kN/m² | Section 4.3 | | Floor vibration | None | At least 8 Hz, span/depth at most 18 | Section 7.5 | | If floor openings exceed 3% | Not in the text | Shell element model and load transfer mechanism | Section 7 | | Temporary stability | No separate heading | Erection sequence and temporary bracing rule | Section 10.2 | | Checklist | None | Table 10.1, eight headings | Section 10.3 | | Fire design | None | Shown by test or by calculation | Section 11 | | Modular and hybrid | None | 14 m limit, 10% rule | Section 12 | ## The regulation annex section by section ### 1. General Principles Scope, related standards and design assisted by testing. - Calculation of fatigue effects is outside the scope. - In seismic design it applies in addition to the TBDY rules. - The informative annexes are for information. - Where there is no adequate calculation model, TS EN 1990 Annex D is the basis for experimental work. ### 2. Material Sheet, steel type, mechanical properties, galvanizing and screws. - Flat product to TS EN 10346, 0.45 to 4 mm. - Minimum yield 250 MPa, tensile/yield at least 1.08. - Elongation at fracture 10% is normal ductility, 16% is high ductility. - The requirements are checked by testing and the results are added to the design report. ### 3. Cross-Section Requirements Ductility class, section ratios, edge stiffener and flange width. - With more than one panel type, the one with the lower ductility governs. - 0.20 ≤ c/b ≤ 0.60 and 0.10 ≤ d/b ≤ 0.30. - Flange width at least 30 mm in C and Σ, at least 20 mm in U. ### 4. Design Principles for Structural Members LRFD, load combinations, tension, compression, bending, shear, combined effects and buckling analysis. - Design is carried out with the LRFD method. - For compression and bending, the Effective Width Method or the Direct Strength Method is chosen. - Basic wind speed cannot be less than 28 m/s, characteristic wind load not less than 0.5 kN/m². - Section 4.11 gives how diaphragm action is modelled in frame analysis. ### 5. Stability Design System stability is provided separately for the whole structure and for each member. - Notional loads are taken as Ni = 0.004 Yi. - Second-order effects and geometric imperfections are considered. - Under the stated conditions, no additional stability bracing is needed for C and Z section beams. ### 6. Panel Design Stud, track, bracing, bridging, anchor and cabinet load. - Stud at least 0.9 mm, web at least 70 mm, edge stiffener at least 9 mm. - Stud spacing for sheathing at most 625 mm. - Only full-storey-height segments carry shear. - Bracing is placed as one continuous member. - Hung cabinet load at least 0.5 kN/m. ### 7. Floor Design Load capacity, deflection, vibration, diaphragm and connections. - Deflection limits are in Table 7.1. - Natural frequency at least 8 Hz, span/depth at most 18. - Joist bearing at least 40 mm. - Above 400 m altitude, ice load is also considered. ### 8. Connection Design Screwed and bolted connections, fracture limit states and screw point types. - φ = 0.55 for screwed connections. - Screw centres at least 3 diameters apart, at least 1.5 diameters from the edge. - Screw spacing at most 200 mm in the chord stud, at most 300 mm in the inner stud. - Shear fracture, tension fracture and block shear are checked. ### 9. Foundation and Anchor Design Foundation selection, shear anchor and hold-down. - A raft or continuous foundation can be preferred; continuous foundations are tied together. - Foundation design follows the TBDY principles. - The hold-down is aligned with the end stud or corner profile and is on both sides. - Embedded anchors are checked to TS EN 1992-4. ### 10. Fabrication and Erection Hole rules, temporary stability and the checklist. - Quality control is carried out to TS EN 1090-1+A1. - Hole diameter/web below 0.40, diameter at most 150 mm. - Until the permanent diaphragm is formed, slender panels and trusses are supported with temporary bracing. - Table 10.1 is used for fabrication and erection checks. ### 11. Fire Design Fire resistance by test or calculation, material and joint factors with temperature. - Tests: EN 1365-1, TS EN 1365-2, TS EN 1364-1. - Yield factor 0.45 at 500 °C. - The protection thickness is maintained at joints. ### 12. Modular and Hybrid Systems Module joint, height limit, load sharing in hybrid buildings. - At most 14 m in a system carried by modules alone. - A rigid core is mandatory above that. - In a hybrid building the limit is 10% of the lateral load. ### 13. Principles of Insulation Application Insulation related to heat, water, sound and services. - Thermal insulation is made to TS 825; a material that provides a thermal break is used at profiles. - Water insulation is made to the Regulation on Water Insulation in Buildings. - For sound, the Regulation on the Protection of Buildings Against Noise applies. - Services are placed so that they do not touch load-bearing members directly. ### Annex. Annex 1 and the Informative Annexes Corrosion classes of the provinces, and informative annexes on design principles, floors, anchors and insulation. - Annex 1: corrosion class of the 81 provinces. - Informative Annex A: design principles and methods. - Informative Annex B: floor design. - Informative Annex C: connection anchor mechanisms. - Informative Annex D: principles of insulation application. ## Who should do what? ### Manufacturer and factory - Review coil certificates against 250 MPa and the DX rule. - Flag load-bearing stud sections under 0.9 mm. - Check hole dimensions against the 0.40 ratio. - Plan your galvanized stock according to the province table. - Turn Table 10.1 into a production form. ### Project engineer - Set up calculations with the LRFD method. - Assess bracing layouts against the one continuous member sentence. - Add the 0.90 ratio to the calculation template for buildings above 10.5 m. - Add the deflection and 8 Hz checks for floors. - Choose the fire design route at the start of the project. ### Contractor and site - Prepare an erection sequence plan. - Put the temporary bracing and prop arrangement in writing. - Discuss temporary loads with the frame designer. - Cover holes made on site with two coats of repair paint. - Keep Table 10.1 records with the panel ID. ### Architect and building inspection - Plan load-bearing panels one above the other on the storeys. - Fix the kitchen and cabinet locations before panel production. - Check floor openings against the 3% limit. - Make insulation and fire decisions together with the panel section. - For projects in the transition period, clarify the governing text in writing. ## Fabrication and erection checklist ### Material check - 1.1 Steel grade: Does the steel conform to TS EN 10346 and TS EN ISO 1461? - 1.2 Quality certificate: Was the mill test certificate of the steel sheet checked? - 1.3 Galvanized coating: Was the coating amount selected according to Annex 1 Table 1? - 1.4 Screws and fasteners: Were the requirements of Section 2 met for the screws? - 1.5 Holes made on site: Were holes and cuts repaired with zinc-rich paint? ### Cross-section requirements - 2.1 Profile dimensions: Do the flange, web and stiffener dimensions meet the limits? - 2.2 Bend radii: Do the inner bend radii meet the limits? - 2.3 Flange width: Does the flange width meet the minimum limits? ### Conformity to the project - 3.1 Profile production: Was the accuracy of the profiles checked against the project? - 3.2 Section check: Were shape, dimensions and surface flatness compared with the project? - 3.3 Screw check: Do the diameter, position and frequency of the screw holes conform to the project? ### Erection - 4.1 Layout: Are the position and alignment of the members correct? - 4.2 Connections: Were the specified number and type of screws used? - 4.3 Anchor installation: Were the anchors installed at the specified diameter and spacing? - 4.4 Connection gussets: Were the gussets fixed with the specified number and size of screws? ### Panel systems - 5.1 Sheathing panel layout: Is the stud spacing at most 625 mm and the studs ≥ 0.9 mm? - 5.2 Panel frame: Are the top and bottom tracks from profiles ≥ 0.8 mm? - 5.3 Screw connections: Were the sheathing panels screwed on all four edges according to the project and TBDY? - 5.4 Horizontal bridging: Was the bridging placed at no more than half the panel height? ### Floor system - 6.1 Floor joists: Are the joists in the section and spacing required by the project? - 6.2 Web reinforcement: Were the stiffeners and connection elements installed in sufficient numbers? - 6.3 Floor connections: Were the web and joints connected with screws as required by the project? ### Fire and report - 7.1 Fire design: Were the requirements of Section 11 met? - 8.1 Design report: Was the calculation report attached? ## Frequently asked questions ### Is it the 2026 or the 2027 regulation? It is the same regulation. It was published in the Official Gazette on 17 May 2026 and takes effect on 1 January 2027. On this site we call it the 2027 regulation, after the year it takes effect. ### When does the light steel regulation come into force? On 1 January 2027. Article 5 of the regulation gives this day as the date of entry into force. ### What is the full name of the regulation? Regulation on the Design, Calculation and Construction Principles of Light Steel Buildings. It was published in Official Gazette No. 33256 of 17 May 2026. ### Which institution issued the regulation? The Ministry of Environment, Urbanization and Climate Change. The enforcement article also names the Minister. ### Which buildings does the regulation cover? Prefabricated, hybrid, modular and on-site profile light steel buildings. Calculation of fatigue effects is outside the scope. ### Does TBDY 2018 Section 10 become invalid? The annex of the new text says that in seismic design this regulation applies in addition to the TBDY rules, and it refers to TBDY Section 10 for panel capacities. The two texts are read together. ### Is there a transition period for ongoing projects? We did not see a separate transition article in the published text. Clarify the status of your project with the project designer, building inspection and the relevant authority. ### What is the minimum stud thickness in the new regulation? At least 0.9 mm for load-bearing studs. At least 0.8 mm for the top and bottom panel tracks. ### What is the minimum yield stress in light steel? 250 MPa. Purlins, façade girts and non-load-bearing studs may use 220 MPa. ### How many g/m² of galvanizing does my province need? Annex 1 Table 1 divides the provinces into two classes: at least 180 g/m² and at least 275 g/m². You can find your province with the lookup tool on this page. ### What is the new rule for bracing? Bracing members are placed as one continuous member between the top and bottom track members of the panel, and their ends are also connected to the studs together with the tracks. ### Is fire design required? Section 11 describes fire resistance design, and Table 10.1 lists it as a separate check item. Performance is shown by test or by calculation. ### Is there a height limit for modular buildings? In systems carried by modules alone, the building height is at most 14 metres. A rigid core is mandatory for taller buildings. ### Where can I get the PDF of the regulation? The download section on this page has an unaltered copy of the Official Gazette annex. The binding text is the one published in the Official Gazette. ### Is this page official? No. It is an independent guide prepared by RENMAE. It does not replace legal or engineering advice. ### Does QSteelCAD check conformity to the regulation? No. QSteelCAD does not perform load-capacity calculations and does not give conformity approval. It performs production-oriented checks; adequacy rests on the project engineer's approval.