This invention relates to a building element for apartment buildings and detached houses, comprised of a fully or partially covering building panel made, for example, from a plaster and paper mixture, alternatively of glass fiber, wood fiber or cement- based panels to be fixed to wood/steel studs.

The most traditional way of constructing current pre-fabricated building elements (infill walls and small-house elements) is a wooden frame with partially broken thermal bridges and a traditional mineral wool, glass wool or, alternatively, cellulose insulation. The wall thicknesses vary up to passive house structures of 500 mm. Besides, the structure is lined with a wind barrier panel/board externally and with a moisture barrier (plastic foil) internally as well as with a cardboard-lined plaster panel. Air leakage levels of 1,5 1/s-m 2 - 0,04 1/s-m 2 are not unusual. Further, the current construction method replaces the organic materials with inorganic material, such as steel and cement-based panels or some other inorganic panel material. All this in order to achieve a maximally moisture and mold resistant building envelope (wall structure) but still with air leakage.

The invention is characterized in that the panels are fixed to the studs by gluing and/or screwing/nailing according to a NO building system, whereby the method results in airtight cells throughout the building element.

The invention relates to an entirely new logistics, assembly and building system giving the client: a logistic and climate-adapted building envelope where air, diffusion and wind sealing is of great importance for a building in terms of energy con- sumption, moisture security, thermal comfort and hygiene, air quality, sound environment, spread of fire and entry of air pollutants from outside. Airtightness is a critical factor both for the durability of the structure and for a good indoor environment in modern buildings. In the long run, airtight houses are also profitable for the actors involved. In the end, for nature as well. Research shows that the heating energy consumption of a house is reduced by almost 30 % if the airtightness (the air permeability, actually) is improved from 0,8 1/s-m ² to 0,4 1/s-m ² . According to this invention, the client obtains an actual air permeability of 0,01/s-m . Such a great decrease in energy consumption is probably not achieved through any other energy improvement measures. The dependent Claims set forth different embodiments of the invention.

An airtight wall element consists of NO classified wood/steel studs of 45 x 45, for example (the dimension of the studs may vary depending on the dimension of the air gap/cell), as well as of NO classified organic or inorganic panel material of 6 mm to 13 mm in thickness. The constructor may determine the wall thickness and the number of wall elements needed based on the required wall-structure U value. All of the screw or, alternatively, nail joints are placed along the longitudinal center line on each stud included in the element, the junction between a vertical and a horizontal stud should be provided with a glued joint. Tight double glued joints should be applied between each panel surface and stud surface, whereas screw or, alternatively, nail joints should be placed between the glue lines, using a C/C distance which may vary depending on the substrate, provided that the requirement on air- tightness is met. A stud-stud and panel interspace forms an airtight cell.

The end result is a building envelope where air, diffusion and wind tightness is of great importance for a building in terms of energy consumption, moisture security, thermal comfort and hygiene, air quality, sound environment, spread of fire and entry of air pollutants from outside in a building. Airtightness is a critical factor both for the durability of the structure and for a good indoor environment in modern buildings. In the long run, airtight houses are also profitable for the actors involved. In the end, for nature as well. Research shows that the heating energy consumption of a house is reduced by almost 30 % if the airtightness (the air permeability, actual- ly) is improved from 0,8 1/s-m to 0,4 1/s-m . According to this invention, the client obtains an actual air permeability of 0,01/s-m ² . Such a great decrease in energy consumption is probably not achieved through any other energy improvement meas- ures.

The invention will be explained in more detail with reference to the accompanying Drawings wherein

Figure 1 shows a wall element including 12 cells. The structure also allows the possibility of filling each airtight cell with a NO classified insulation material. Figure 2 shows a NO building system airtight "Singel" where a simple single element consisting of a stud frame of 45 x 45 c/c 600 m and a simple building panel of 10 mm on both sides can be seen. No thermal bridge break, glued and screw/nail joints made according to NO building systems.

Density 18 kg to 26 kg/m ² V thickness 65 mm Figure 3 shows a NO building system airtight "Singel + Singel" where two single elements structured as above but, on the contrary, connected in parallel can be seen. No thermal bridge break. A thermal bridge break can be obtained by offsetting one of the building elements by 300 mm, for example, glued and screw/nail joints made according to NO building systems.

Density 36 kg to 52 kg/m ² V thickness 130 mm

Figure 4 shows a NO building system airtight Kombi thermal bridge break where the same single elements as in Figure 1 and Figure 2 combined with a one-sided airtight 300 mm offset panel and stud frame can be seen. A clear thermal bridge break can be seen here, glued and screw/nail joints made according to NO building systems.

Density 27 kg to 39 kg/m ² V thickness 120 mm

Figure 5 shows an example of a combined single element with a thermal bridge breaking stud "Smart" having an insulation and free dimensions. The different combination possibilities of a single element for creating double airtight cells (air gaps) by means of NO airtight building systems can be seen here. The internal installation space created in order to allow electricians and other installers to work without puncturing the airtightness of the NO building envelope can also be seen here. Glued and screw/nail joints made according to NO building systems. Density 59 kg/m ² V thickness 225 mm

Installation of elements

NO building systems create new conditions for achieving a controlled airtightness in apartment buildings and detached houses in a controlled, practically applicable way. Thanks to the construction principle "Singel" element, multi-layered panel structures open the possibility of a quality-guaranteed production and a quality- guaranteed assembly system.

NO wall systems can, in regulated forms, be installed in multi-layered "Lego" systems with an overlap fit in order to achieve a quality-guaranteed airtightness in the building envelope. Production

NO building systems refer to a new building system resulting in a building element with a higher pre-fabrication level for apartment buildings and detached houses. NO wall systems are intended to be pre-fabricated in a factory environment under strict control and thorough quality assurance. Due to the element structure containing in- trastructural massive panel material, through holes can be made in the panel material using methods available on the market.

Transportation

NO building systems can, thanks to their shear stability and light structure, be trans- ported and handled with a moderate truck and crane capacity. The built-in internal stability of the wall system helps it to maintain its dimensional and fitting accuracy.

Moisture ratio certification/fire protection

The new inventive product NO wall system can be treated using a "WSJ" treatment method leading to an entirely new technique of installing building structures, such as walls including organic building material. The WSJ method allows the panels and the wooden stud frame to attain a moisture ratio certification with a documented critical moisture ratio (mold resistant). The structure and the wooden studs may attain a moisture ratio certification >90% as well as a moisture ratio certification and fire protection class B-sl, dO, respectively. "WSJ" treated panels are not necessary in certain definitely dry premises.

The invention also allows wall thicknesses above the known standard. The invention is not limited to the above-described example but may vary within the scope of the accompanying Claims.