Q&A about Rubner Haus construction

Whether your questions might relate to the different construction systems, the origin of the wood, or how a Rubner Haus behaves with heat, cold or moisture - we are experts in our actions and activities as a result of our 50 years of constructing wood homes and more than 90 years of experience in wood processing. We are happy to answer the questions most often asked by our customers regarding your house and the limitless possibilities available.

The Rubner value chain is unique and starts in our own forest. Some of our wood comes from our sustainably managed forests and is processed into construction wood, glued laminated wood, solid wood panels, wood doors and wood windows at different companies within the Rubner Group. The rest of the wood comes from Alpine forests, mainly in Styria and South Tyrol, and it is of course PEFC-certified. The „Programme for the Endorsement of Forest Certification Schemes“ (PEFC) is an international forest certification system. It is the world’s largest independent organisation aimed at safeguarding and continuously improving sustainable forest management, while guaranteeing ecological, social and economic standards.

Spruce and larch are used as construction wood. All types of wood can be used for surface areas (cladding, floors, …).

C O L D
Wood homes are very well insulated from inside the house. You could even say that they are thermal bridge-free as a result of the good lambda value of wood. The insulating values achieved with wooden constructions can be even higher than those with solid structures (including brick and concrete) with the same wall thicknesses.

H E A T
Wood homes provide outstanding thermal insulation in summer in principle. However, the design of the shading and the insulating material selected are crucial here. As far as the insulating material is concerned, the higher the specific thermal capacity the better. The phase displacement of a construction component provides the value for how long the component is able to withstand heat, or how long heat needs to pass through the component. This phase displacement ensures that the midday heat does not pass through the component (external wall or roof) at the same time. It describes the time frame and displacement in which the maximum daily temperature passes through the component from the external side to the interior, and reduces the outside temperature to the inside temperature provided into the rooms. Values of between 10 to 13 hours are perfect here, as it can be assumed that the heat that has then arrived inside by then is able to escape through ventilation in the evening. The inhabitants of the house can then sleep comfortably again with the cool air from the evening.

M O I S T U R E
Rubner Haus homes have no diffusion barrier. The primary objective is to keep the wall structure free from moisture at all times, i.e. to prevent warm and moist air from condensing at some point. Moisture is the enemy of any house, whatever the construction. A wood wall with no diffusion barrier is always more permeable from the inside out. The dense construction materials – such as vapour retarders – are assembled on the interior side of the wall. You need components on the outside for this that are significantly more permeable (with no diffusion barrier), e.g. plasterboard or cork. Anything that makes its way through the vapour retarder can escape outside, and the wall structure remains dry. Diffusion through a wall is a relatively slow phenomenon. When large amounts of moisture are produced (from cooking, showers, or when lots of people come to visit) the air humidity is forced upwards even with a wall that has no diffusion barrier, and ventilation or a ventilation system are required in addition.

The airborne sound insulation of the partition walls is solved using a double decoupled wall construction. This is an extremely effective solution and is better than building a double wall. The sound is lost in the different heavy layers of the wall structure.

The modern wood constructions from Rubner Haus meet the same safety regulations as all other construction systems. However, the main thing is that wood burns in a more predictable and controlled manner than steel. Solid wood ceilings and beams survive most fires, thereby allowing the inside of the building to be extinguished. Wood chars on the surface in the event of a fire, thereby protecting the wood itself from being destroyed completely. The core of the wood remains intact and therefore capable of supporting loads. Steel on the other hand collapses under high temperatures.

Some of the benefits of a prefabricated wood home as compared with a traditional construction:
- The walls are prefabricated at the production facility and delivered completed to the construction site where they are then simply assembled. The walls are already insulated and plastered, the windows and roller blinds are installed, as are the electrical fixtures, and also the plumbing connections. This guarantees high and controlled design quality.
- The house is erected within just a few days (the building is then weather-proof after a few more days).
- The assembly of prefabricated components removes the need to wait months for masonry, plaster, concrete, etc. to dry.
- A point of contact is available for all queries.
- The client does not need to arrange the coordination between all the different trades involved.
- No time-consuming selection or coordination of the tradespeople is required with wood constructions. This means that the construction saves the client’s time.
- Precise prefabrication at the plant avoids complications and the need for improvisation at the construction site.
- Pre-assembly at the plant means that the project does not depend largely on the weather and is therefore more predictable.
- Costs & adherence to agreed deadlines: A fixed price and fixed handover date are agreed before the contract is signed.
- Prefabricated houses do not all look the same. Modern wood homes from Rubner are designed individually in line with an architect’s design and the client’s wishes.
- Wood constructions are ideal for earthquake zones as a result of the low dead weight and the ductile joints.
- The client’s requests can be accommodated at the construction site and during construction. Our collective goal is to reduce the need for improvisation during construction using good advance planning in order to avoid quality problems and additional costs.
- Good empirical values in different cultures. Wood homes can age more than 100 years without any problems (value stability). There are many examples of houses that are several hundred years old and that are still inhabited and meet the requirements of modern heat protection today.
- Wood homes generally have the same insulating properties but lower wall thicknesses than traditional solid constructions. This saves the cubic content and thereby increases the useful space.
- Wood homes feature a higher level of living comfort as the surfaces of the construction components are warmer compared with masonry buildings„“.

The sales employee prepares a quote query following a detailed discussion (needs assessment) with the customer, and the quote is then developed by the Quote Office in Chienes. This is then discussed between the salesperson and the customer. All necessary negotiations take place until the contract is signed. The next steps are also coordinated and a rough timeline is set out. The salesperson is the customer’s first point of contact. The Assembly Group Leader is an additional point of contact for technical matters at the construction stage.

There are four clear unique selling points in favour of Rubner.

1 ) THE RUBNER VALUE CHAIN:
Rubner forest. Rubner wood. Rubner sawmills. Rubner doors. Rubner windows. Rubner house. Rubner wood construction. The trees that we use come from our own forest in Mezzaselva near Bressanone in South Tyrol and from certified Alpine forests. We cut the wood at our own sawmills in South Tyrol, East Tyrol and Styria in accordance with the highest quality standards and then process it further in the companies within the Rubner Group. Our products are made at our plant in Chienes. The windows and doors are also made by Rubner. We also have our own assembly teams who ensure that all parts of the Rubner Haus are constructed perfectly. This means that we know every tree that is used and monitor each work step up until the house is completed. Only Rubner Haus provides this level of service compared with our national and international competitors.

2 ) THE BEST OF TWO CULTURES:
Rubner combines Italian flair with German reliability and precision. We make the most of our unique location in South Tyrol at the intersection between two cultures.

3 ) EVERY RUBNER HAUS IS THE BEST RUBNER HAUS:
After more than 90 years of experience in wood finishing, combined with research and development along with various national and international certifications, we can say one thing with certainty: we are technological market leaders and provide the most effective construction system on the market with four different wall systems made from natural materials. This way we can fulfil each individual requirement. We don’t follow trends. We set them.

4 ) THE RUBNER WORLD:
At our headquarters in Chienes includes 30,000 m² of space for example houses of different styles, the production facility, research laboratory, the Finishings department, the „Wood Perspectives“ experience trail and the World of Rubner Doors. This makes Rubner World one of the top experience parks for home construction in Europe. It is the only one of its kind in the whole of Italy.

Overall production takes no longer than 2 – 2.5 months. The specific cases always depends on certain factors, such as the type of house (Blockhaus/residential) and its size (surface area, one or more storeys, ceilings, roof types and roofage). PRACTICAL EXAMPLE: A detached family home with approx. 140 m² of gross surface area only takes around 3 working days at our plant. However, the doors, windows and stairways also need to be produced at the same time. All fittings and fixtures also need to be ordered and installed. This results in a time frame of 2 – 2.5 months.

When selecting new products, Rubner makes sure that it selects ecological, sustainable products that are not harmful to health – both in order to protect the end-customer and its own employees. Rubner also has all of its products monitored by independent institutions such as Holzforschung Austria, Bund Deutscher Fertigbau, Gütegemeinschaft Blockhaus and Federlegno, which thereby also safeguards the country-specific product certifications. Rubner also engages in continuous dialogue with technical experts and research institutes. However, some people can still have an allergic reaction to natural products. Rubner Haus has an internal Product Development department that listens to suggestions in this regard and develops customer-specific solutions without impairing product quality.

Wood constructions are particularly suited to earthquake zones as a result of their low dead weight. The lower the building mass, the lower the horizontal force in the event of an earthquake. The wood and steel joints used in wood constructions are also ductile, i.e. deformation and recovery take place without any damage being caused. Cracks can occur in the masonry of conventionally constructed buildings and they can collapse.

The windows and doors are strictly tested for safety from break-ins.