Question 1

What insulation is used?

Accepted Answer

ZTC uses mineral wool, cellulose insulation and wood fibre insulation. The company operates an industrial Isofloc system for blowing cellulose and wood fibre insulation.

Question 2

How are panels connected?

Accepted Answer

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.

Question 3

What about sound in timber houses?

Accepted Answer

Airborne sound performance in timber houses can be very good. Impact sound in intermediate floors is addressed with appropriate floor and ceiling solutions.

Question 4

What is the difference between CLT and timber frame?

Accepted Answer

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.

Question 5

How does ZTC differ from other panel house manufacturers?

Accepted Answer

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.

Question 6

What is the wall U-value?

Accepted Answer

Depending on the construction, ZTC timber frame walls can achieve a U-value of approximately 0.12–0.15 W/m²K. Wall thickness is typically 250–400 mm. The exact solution is determined during design and energy assessment.

Question 7

What is the n50 value?

Accepted Answer

The n50 value describes building airtightness. In quality constructions it is possible to achieve n50 below 0.6, which is important for energy-efficient buildings.

Question 8

Is it possible to achieve A+ energy performance class?

Accepted Answer

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.

Question 9

When is the energy assessment carried out?

Accepted Answer

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.

Question 10

Is a timber house suitable for the Latvian climate?

Accepted Answer

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.

	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 3–5 days per floor.	On-site assembly typically around 3–5 days per floor.

CLT panels for timber construction

ZTC experience and production facts

When CLT panels are appropriate

CLT panel technical parameters

Maximum panel size

Building height

Fire resistance

Acoustics

CLT applications and typical scenarios

CLT may suit

Timber frame is often practical

Brief CLT vs timber frame comparison

Family House

Industrial Facility Facade with CLT and Infill Panels

Material Harmony: The Interplay of Metal, Ash, and CLT

Residential Complex

Modern Coastal House with Curved Timber Structures

Sustainable Engineering: The CLT & SiOO:X Home

Frequently asked questions

Are CLT panels suitable for your project?