
CLT panels for timber construction
CLT panels are used for solid timber load-bearing structures, hybrid systems and multi-storey timber buildings. ZTC combines factory production precision with experience in these forms of construction.
ZTC experience and production facts
35+
years of experience
400+
completed projects
14
European countries
±1 mm
CNC precision
When CLT panels are appropriate
CLT panels are solid timber structural elements. Their suitability depends on the architecture, loads and energy performance requirements. ZTC helps compare them with timber frame panels and provides information on structural certification. Read about CLT houses or browse completed projects.
CLT panel technical parameters
Indicative technical limits and capabilities to consider during design and production planning.
Maximum panel size
13,800 × 3,100 mm
Building height
up to 8 storeys
Fire resistance
up to EI 120
Acoustics
up to Rw 65 dB
Where to use CLT
CLT may suit
- Solid timber load-bearing structures and multi-storey timber buildings.
- Hybrid solutions where CLT is used in specific zones.
- Projects with exposed timber surfaces and higher structural demands.
Timber frame is often practical
- Private homes up to around 3 storeys where timber frame is cost-effective.
- When the priority is an insulated panel system with factory preparation.
- When flexible scope and fast panel assembly matter most.
Brief CLT vs timber frame comparison
Use this as a starting comparison. Each project's architecture, loads, energy performance and specification need a separate assessment.
| CLT | Timber frame | |
|---|---|---|
| Structure type | Solid timber panels as the load-bearing structure. | Frame system with an insulated panel solution. |
| Height | More often multi-storey and hybrid projects. | More often private homes up to around 3 storeys. |
| Production | Panels are factory-made with ±1 mm CNC precision. | Panels are factory-made with ±1 mm CNC precision. |
| Assembly | On-site assembly typically around 3 to 5 days per floor. | On-site assembly typically around 3 to 5 days per floor. |
Related ZTC projects

Private residence
Modular House in Iceland
, Iceland
View project
Developer project
Industrial Facility Facade with CLT and Infill Panels
, Latvia
View project
Private residence
Material Harmony: The Interplay of Metal, Ash, and CLT
Nijmegen, the Netherlands
View project
Private residence
Authentic-Style Two-Storey House
Amsterdam, Netherlands
View project
Private residence
Modern Coastal House with Curved Timber Structures
Akershus, Norway
View project
Private residence
Sustainable Engineering: The CLT & SiOO:X Home
Leinster, Ireland
View projectRelated topics
- CLT housesZTC helps assess CLT houses and hybrid structures alongside its factory-made timber construction options.
- Hybrid timber constructionHybrid timber construction combines timber frame and CLT with steel or concrete to meet the demands of complex projects.
- Multi-storey timber buildingsTimber systems for multi-storey buildings, including CLT structures up to 8 storeys and hybrid options made with factory precision.
- CE and ETA certified timber structuresCE marking and ETA-21/0014 European Technical Assessment for the ZTC timber construction system.
Frequently asked questions
Questions about CLT panels, technologies, comparisons and energy performance.
Comfort panels use mineral wool within the frame. Premium and Lux use wood fibre or cellulose insulation; Premium adds a 22 mm wood fibre windproof board, while Lux adds a 40 mm STEICO THERM wood fibre layer. Additional 45 mm internal insulation and plasterboard are excluded from these packages. For Comfort, Premium and Lux, roof panel insulation is 50 mm thicker than the insulation in the corresponding external wall.
Panels are connected with long screws or special timber connectors. A wind barrier is used externally, a vapour control layer internally, and membranes are carefully taped across the building.
Panels are connected with long screws or special timber connectors. A wind barrier is used externally and a vapour control layer internally, with membranes carefully taped across the building.
Airborne sound insulation in timber houses can be very good, especially with cellulose or wood fibre. Impact sound in intermediate floors should be addressed with appropriate floor and ceiling solutions.
Airborne sound performance in timber houses can be very good. Impact sound in intermediate floors is addressed with appropriate floor and ceiling solutions.
For houses up to around 3 storeys, timber frame is often more economical. CLT may suit load-bearing structures, hybrid solutions or where exposed solid timber walls are desired.
For houses up to around 3 storeys, timber frame is often more economical. CLT may suit load-bearing structures, hybrid solutions or exposed solid timber walls.
ZTC manufactures and assembles houses itself, has 34 years of experience, CE and ETA-21/0014 certification, Hundegger CNC precision of ±1 mm and an industrial insulation installation system.
ZTC manufactures and assembles houses itself. The company has 34 years of experience, CE marking and ETA-21/0014, Hundegger CNC precision of ±1 mm and an industrial Isofloc insulation system.
The wall U-value is calculated for the individual project using all wall layers, material properties and structural junctions. Comfort, Premium and Lux differ in frame, insulation and barrier construction; the panel specification name alone does not determine a guaranteed U-value.
The n50 value describes the airtightness of the whole building. The target is set in the design and the achieved result is verified by a building airtightness test. Joints, windows, doors and assembly quality also affect the result; the panel specification alone does not guarantee a particular n50 value.
Yes, ZTC structures can be adapted for A+ energy performance class. The result depends not only on wall insulation but also on building form, windows, orientation, airtightness, ventilation and heating systems.
Yes, ZTC structures can be adapted for A+ energy performance class. The result depends on insulation, thermal bridges, building airtightness, windows, orientation, ventilation and heating systems.
A preliminary energy assessment is carried out during the design stage before construction and the building authority process. It helps determine whether additional insulation or other technical measures are needed.
A preliminary energy assessment is carried out during the design stage before construction starts. It helps determine whether additional insulation or other technical measures are needed. After construction, a final assessment follows to confirm compliance.
Yes, timber structures are suitable for the Latvian climate when correctly designed, insulated and built. ZTC structures are adapted to the energy performance requirements of each project.
Yes, timber structures are suitable for the Latvian climate when correctly designed, insulated and built. ZTC structures are adapted to each project’s energy performance requirements.
Are CLT panels suitable for your project?
Send us the project details. We will help compare CLT, timber frame and hybrid options.