Our modular building technology involves prefabricating residential modules with the use of cross-laminated timber (CLT) in one of three standards of finish. This allows us to create single-family homes, apartment buildings, hotels, office buildings, dormitories, retirement homes, and much more.

Modular prefab is a construction method where entire sections of a building are manufactured in a factory as pre-made modules. These modules come complete with flooring, walls, and ceilings, and are finished both inside and outside, according to the standard ordered by the client. Once completed, the modules are transported to the construction site on trucks, where foundations and utility connections are prepared in advance. Using cranes, the modules are lifted off the trucks and placed onto the foundation. They are then assembled together and secured to the foundation. On-site work involves connecting utilities between modules, hooking them up to the provided connections, and finishing the building, if the client’s order does not include a “turnkey” solution.

Our clients have the option to choose from three standards of finish:

• shell and core
• basic finish
• turnkey finish

For detailed information on the scope of these finishing standards, please consult with our sales representatives.

CLT (Cross Laminated Timber) is a structural material in the form of panels that we use to build our modules. It is entirely made from solid wood and typically consists of 3, 5, or 7 layers of wooden sheets, alternately glued together in perpendicular orientation. This layering provides high strength in both directions and substantial rigidity to the structure. The types of wood commonly used are mainly higher-grade spruce and fir.

Precision and quality of execution – CLT panels are manufactured in the factory and cut to project-specific dimensions using CNC machines with an accuracy of up to 1 mm, eliminating dimensional errors commonly seen in concrete and masonry buildings. With CLT technology, there is no need to re-mill door openings that don’t fit or remeasure walls after they have been erected. Doors can be ordered in advance since the door openings in CLT panels are cut to 1 mm precision.

Durability – CLT is a highly robust and durable building material capable of withstanding significant multi-directional loads, unlike traditional structural wood. This strength comes from the cross-lamination bonding technique.

Assembly time – With the CLT panels custom-made in the factory, construction time is significantly reduced compared with concrete and masonry techniques. Additionally, modular construction transfers most of the building process to the factory where our modules are manufactured. As a result, on-site assembly can be completed in just a few days, making the home ready for occupancy much faster than in the case of traditional technologies.

Excellent thermal and insulation properties – CLT panels offer better thermal properties compared with concrete and masonry, allowing to use thinner layers of thermal insulation on walls, floors, and roofs, which translates into a lower construction cost. Our modular homes meet low-energy building criteria.

Air tightness and vapor permeability – CLT is believed to be one of the most airtight construction materials, allowing for automatic regulation of humidity levels inside buildings.

Phase-shift effect – Cross-laminated timber buildings do not heat up quickly in hot weather or cool down abruptly during sudden temperature drops. External temperature changes affect internal temperatures with a delay.

Excellent acoustic properties.

Fire resistance – CLT structures exhibit high fire resistance due to the inside-to-outside charring process. The charred layer of wood restricts access of oxygen to the core, which slows down combustion. Fire resistance class of CLT: D-s2, d0.

Lower self-weight – Owing to the high strength of CLT panels and minimal thickness of the structural elements (walls and floors), the overall weight of the building is much lower compared with concrete and masonry structures, resulting in significantly lower foundation costs. At the same time, CLT panels are made from solid wood, ensuring stability even in strong wind conditions, unlike timber frame constructions.

Environmental benefits – Wood, used as the natural raw material for manufacturing CLT panels, offers numerous advantages over conventional technologies: it is renewable – constantly replenishing; it is a natural carbon sink, absorbing CO^₂ and actively contributing to climate protection; it is a natural energy store; it can be recycled in a 100% environmentally friendly way. Wood is beautiful and cozy – using CLT as the structure for our modules, we emphasize the beauty of wood as a natural material. A CLT home is cozy not only because it’s warm, but also because staying in a wooden home has a calming effect on the senses, improves your mood, and the smell of wood promotes relaxation.

The first step in CLT panel production involves acquiring raw wooden boards, which are dried, planed, and cut, and then joined with micro-joints to form long lamellas. Each layer of CLT must be made from wood of the same strength class. Typically, the higher strength classes (C24 and above) are used for the longitudinal layers, whereas the perpendicular layers are made from at least C16 strength wood. Spruce is the type of wood we use the most commonly. The boards used for CLT elements typically range in thickness between 10 and 50 mm.

The second stage of production entails arranging the prepared wooden lamellas in layers that are perpendicular to each other and gluing them together to create the finished CLT product. The panels consist of an odd number of layers – 3, 5, or 7. Melamine (MUF) and polyurethane (PUR) adhesives are commonly used for bonding the individual layers. These adhesives must meet strict formaldehyde emission standards and are harmless to the health during production, use, and even in the case of a fire. Glued does not need to be applied to the side surface of the battens, which can be spaced up to 6 mm apart. Cross-laminated timber is glued in hydraulic or vacuum presses. In both cases, the appropriate pressure is applied to the bonded elements to ensure a durable connection.

CLT panel dimensions typically range from 60 to 400 mm in thickness, up to 3.5 m in width, and up to 20 m in length.
Common wood species used include spruce (most frequently), fir, pine, and larch.
Moisture content:11% ± 2.
Volumetric density: 450 to 500 kg/m³.
Thermal conductivity coefficient (λ): 0.12 W/mK.
Specific heat capacity: c = 1600 J/kgK.
Fire resistance class: D-s2, d0.
Sealing: the panels are airtight (3 or more layers)

Our modules can be finished with two types of surface treatments for CLT panels:

Invisible surface – used on the exterior and also inside the modules where it will be covered with flooring layers, plasterboards, or other wall and ceiling finishes. This surface option meets all the structural requirements but does not need to meet the improved visual standard – it may feature more knots, gaps between the lamellas, discoloration, and can include various wood types.

Visible surface – applied inside the modules, on walls and ceilings that will remain exposed. It consists of micro-jointed lamellas of uniform wood type, ensuring a consistent texture and grain. Knots and small gaps between lamellas are permissible but occur only to a minimal extent. The visible surface requires no additional processing; it can be compared to a plastered and painted wall in traditional construction.

CLT offers high thermal insulation properties compared with concrete and masonry.
The U-value of CLT is significantly lower than that of concrete and brick walls (of the same thickness).

Comparison for 20 cm thick wall:
CLT U-value = 0.59 W/m²K
Concrete U-value = 3.2-3.7 W/m²K
Brick U-value = 1.8-2.5 W/m²K
The U-value indicates how quickly heat escapes through a building element (e.g., wall, window, or roof). A lower U-value indicates that less heat is lost through the structure, indicating better thermal insulation.

CLT also has a higher specific heat capacity compared with concrete and brick:
CLT specific heat capacity (c) = 1600 J/kgK
Concrete specific heat capacity (c) = 1000-1300 J/kgK
Brick specific heat capacity (c) = 800-1000 J/kgK
Specific heat capacity measures a material’s ability to store heat and indicates how long the material will release heat after reaching thermal equilibrium. A higher specific heat capacity means the material stores heat better and releases it more slowly to the surroundings.

Moreover, the thermal conductivity indicator (λ) of CLT is lower than that of concrete and brick:
CLT λ = 0.12 W/mK
Concrete λ = 1.5-2.0 W/mK
Aerated concrete block λ = 0.2-0.38 W/mK
Brick λ = 0.64-0.9 W/mK
Mineral wool λ = 0.035-0.045 W/mK
Thermal conductivity (λ) indicates how well a material conducts heat. A lower λ value signifies better thermal insulation properties.

For the final layer of facade, horizontal tongue-and-groove cladding made of natural wood is the recommended solution. The client chooses the type and color of the wood, for example Spruce or Okuma.

Modern facade panels are an excellent alternative approach:

Rockpanel boards – these panels are primarily composed of basalt, offering a wide range of colors and providing a modern facade effect.

Equitone / Cembrit Facade Panels – these fiber-cement panels come in various textures and colors, allowing for versatile facade designs.

Standing Seam Metal Sheets – cladding made from metal laid in the “standing seam” system. It gives the facade a minimalist, contemporary appearance.

Each of these options offers distinct aesthetic qualities and flexibility in facade design.

In the construction process of our CLT modules, we use facade layers compliant with the standards required for homes intended for year-round occupancy. These layers serve as thermal and acoustic insulation and protect the walls from the outside. Thus, CLT panels are not exposed to external weather conditions. Wooden boards or facade panels are used as the final (external) layer of cladding.

However, if CLT wood is subjected to prolonged exposure to weather conditions, its outermost layer will respond like any other wood. Under the influence of precipitation and high humidity, wood alternately swells and shrinks. This phenomenon is known as volumetric fluctuations. These fluctuations are exacerbated by temperature changes and can lead to the formation of micro-cracks. Unlike traditional wood, however, CLT sections do not lose their structural strength due to this process. Nevertheless, the formation of gaps between the lamellas of the outermost layer may affect the visual properties of a CLT wall. Additionally, exposure to UV radiation causes oxidation of the wood’s surface layers, resulting in color loss or a bluish tint.

For these reasons, we do not recommend using CLT as a layer exposed to atmospheric conditions for longer periods. If a client wishes to use CLT for elements such as a pavilion, the CLT elements should be protected with traditional wood preservation treatments.

The functional layout of our modular buildings is designed to maximize space efficiency and adaptability to the planned number of residents or users. The buildings can be expanded by adding additional modules.

The room layout can be slightly modified by adding lightweight internal partition walls. However, it is important to note that additional window and door openings cannot be cut, and the structural walls designed as load-bearing sections cannot be moved.

INTRO, Cleveland, USA – residential building
https://www.binderholz.com/en-us/mass-timber-solutions/intro-cleveland-usa/

Quartier Prinz-Eugen-Park, Munich, Niemcy – residential building
https://www.binderholz.com/en-us/mass-timber-solutions/quartier-prinz-eugen-park-munich-germany/

Hotel MalisGarten, Zell am Ziller, Austria – hotel
https://www.binderholz.com/en-us/mass-timber-solutions/hotel-malisgarten-zellamziller-austria/

Coffee Production Plant Johannson, Vestby, Norway – industrial building
https://www.binderholz.com/en-us/mass-timber-solutions/coffee-production-plant-johannson-vestby-norway/

Uderns, Austria – single-family house
https://www.binderholz.com/en-us/mass-timber-solutions/single-family-house-uderns-austria/

Training center ‘Centre de Compétences’, Bettembourg, Luxembourg – office buildings
https://www.binderholz.com/en-us/mass-timber-solutions/centre-de-competences-training-centre-bettembourg-luxembourg/

Complex ‘Integration Linköping’, Sweden – residential buildings
https://www.hasslacher.com/residential-complex-linkoeping

HBLA Pitzelstätten Klagenfurt-Wölfnitz, Austria – student dormitories
https://www.hasslacher.com/en-hbla-pitzelstaetten

HOHO VIENNA, Vienna, Austria – office building
https://www.mm-holz.com/en/references/hoho-vienna

WOODIE, Hamburg, Niemcy – residential building
https://www.mm-holz.com/en/references/woodie

Youth center ECHO, Graz, Austria – office building
https://www.mm-holz.com/en/references/echo-youth-centre

HUMMEL BARRACKS, Graz, Austria – residential building
https://www.mm-holz.com/en/references/hummel-barracks

PAULASGASSE, Vienna, Austria – residential building
https://www.mm-holz.com/en/references/paulasgasse