Google review
ZTC built my house in 2012, and they have done some reclamation work in two periods since then. Only positive experiences with ZTC! Good quality of workmanship and customer support.

An A+ rating reflects the performance of the whole building. ZTC manufactures the structure and panels to meet the design and energy audit requirements.
35+
years of experience
400+
completed projects
14
European countries
±1 mm
CNC precision
An A+ rating depends on windows, orientation, thermal bridges and airtightness, as well as heat recovery ventilation and the heating system. Wall thickness, from 250 to 400 mm, is chosen to suit the design and energy audit. Read about energy-efficient timber houses and cellulose insulation.
The A+ class applies to the whole building. ZTC supplies the timber structure, insulation and membranes within the agreed scope. An independent certified specialist carries out the energy audit during design.
Manufacture and assemble the structure according to the approved project and scope.
The energy audit at design stage determines appropriate wall thickness and systems.
Depends on project, insulation and energy audit requirements.
The energy audit determines the appropriate design. Wall thickness alone is not enough to establish it.
Clients describe ZTC's precision, organised process and professional communication in their Google reviews.
Google review
ZTC built my house in 2012, and they have done some reclamation work in two periods since then. Only positive experiences with ZTC! Good quality of workmanship and customer support.
Google review
Ļoti profesionāls un ieinteresēts darbs no ZTC puses, lai maksimāli izpildītu klienta vēlmes mājas būvniecībā, ieguldot laiku visu detaļu precizēšanā, kā rezultātā pašas būvniecības laikā neko nevajadzēja koriģēt un ir tapusi patiesi kvalitatīva māja. Atzinīgus vārdus par mājas būvniecības kvalitāti saņēmām no visiem speciālistiem, ar kuriem sadarbojāmies vēlāk - liekot logus un durvis, jumta segumu un apdari. Paldies par paveikto un varam tikai ieteikt citiem izmantot ZTC pakalpojums māju būvniecībā! Pateicībā, Irēna un Janeks
250 to 400 mm depending on project and audit.
Approximately 0.12 to 0.15 W/m²K depending on solution.
n50 < 0.6 possible with quality execution.
Heat recovery is important for whole-building energy performance.
An independent certified specialist carries out the energy audit during design, allowing options to be compared before production and assembly. ZTC is responsible for the structure; achieving A+ depends on the design of the whole building.
Use the calculator to compare specifications and estimate a starting budget before we review your project.

Private residence
Gelderland, Netherlands
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Private residence
, Sweden
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Private residence
Amsterdam, Netherlands
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Private residence
Akershus, Norway
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Private residence
Leinster, Ireland
View project-1.jpg&w=1920&q=60)
Private residence
Oslo, Norway
View projectQuestions about A+ class, energy performance and price.
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.
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.
From EUR 430/m² excluding VAT. The starting price covers an insulated, weather-protected timber frame panel package (shell), using the Comfort specification for a rectangular house with a simple layout and at least 150 m² of gross area. The EUR 430 and EUR 500/m² starting prices apply only from 150 m² gross area, subject to the conditions of the respective solution. Smaller houses require an individual quotation.
From EUR 430/m² excluding VAT. The starting price covers an insulated, weather-protected timber frame panel package (shell), using the Comfort specification for a rectangular house with a simple layout and at least 150 m² of gross area. The price is calculated using gross area measured along the exterior perimeter of the building. This is not the heated or usable internal area. We agree the area calculation and specification in the project quotation. The exterior-complete house is quoted individually. The stated starting prices of EUR 430 and EUR 500/m² excluding VAT are achievable only for houses with at least 150 m² of gross area and the specification and shape required for the respective starting price. Houses below 150 m² require an individual quotation; the starting rate cannot simply be multiplied by a smaller house area. For example, we do not offer panel production and assembly for a 100 m² house at EUR 43,000 excluding VAT based on the EUR 430/m² starting price.
Budget separately for foundations, plinth, interior finishing, building services, project documentation, crane hire, scaffolding, fencing and worker accommodation where needed. Delivery and assembly are included.
Both packages exclude foundations and plinth, interior finishing including plasterboard installation, electrical installation, heating, water and drainage, and ventilation. Also budget for architectural design, approvals, necessary surveys, external utilities and commissioning. The price includes panel delivery, assembly and worker transport to the site across Europe, Scandinavia and the United Kingdom. The client provides accommodation for workers where needed and pays site costs: crane hire, scaffolding and site fencing. Delivery sequence, site access and assembly arrangements are agreed in the project quotation.
Send us the project details so we can assess the structure and specification.