The construction of single-story homes using sandwich panels with the Rauta frameless technology allows for the construction of a modern, energy-efficient, and long-lasting building as fast as possible.
Because of their advantages, sandwich panels are widely used in the construction of the envelopes of prefabricated commercial buildings. At the same time, the contemporary trends in residential architecture prove that the use of sandwich panels also helps to create energy-efficient houses with defined and stylish design.
A house made of sandwich panels is reliable, durable, and eco-friendly, uses minimum amounts of energy for heating and air-conditioning, and doesn’t require any special maintenance during operation. The home’s internal layout concept is based on the premise’s simplicity and functionality and provides optimal living comfort.
The Rauta frameless technology can be used in the construction of single-story sandwich panel houses, as well as trade centers, administrative, utility, and other buildings.
Energy efficiency
120 to 200 mm Ruukki panels with polyisocyanurate foam (PIR) core are used construct floor, walls, partitions, and the roof. PIR panels are the most energy-efficient construction elements, ensuring efficient wall thermal conduction (λ = 0,022 W/m·K.) For instance, 160 mm thick Ruukki PIR panels have a thermal resistance of R=7.43 m2K/W, at the minimum permissible value in accordance with DBN B.2.6-31 for the I temperature zone is Rmin=4.0 m2K/W for walls and Rmin=7.0 m2K/W for roofs. To optimize the cost of the building, interior sandwich panels have the same characteristics as sandwich panels for external walls.
In terms of thermal resistance, a 160 mm thick wall made of Ruukki PIR sandwich panels is similar to a 850 mm thick aerated concrete wall or 2.6 m thick ceramic brick wall.
To ensure the maximum energy efficiency of a house, it is recommended to use Ruukki Energy sandwich panels, which reduces the building’s energy consumption by 20%, compared to standard panels, as a result of air-tight structure joints, which ultimately ensure low air permeability (≤ 1.0 m3/m2h).
A comparative calculation of annual heating costs showed that a frameless house made of sandwich panels with a floor area 65 m2 consumes 31% less heat energy (6,902 kWh, energy consumption class A) than a similarly sized house made of aerated concrete blocks with mineral wool insulation (10,003 kWh, energy class B).
As an option, solar panels can be installed on the roof which increases the energy independence of the house. For instance, approximately 60 m2 of solar panels generating about 26,000 kWh/year, can be installed onto a 80 m2 house. With the average energy consumption by a family of 3 persons of 6,000 kWh/year and the estimated heating consumption of a house being about 9,000 kWh/year, this provides for an energy surplus of 11,000 kWh/year, which can be sold at “green” tariff rates.
The use of Ruukki sandwich panels assists in creating a Passive House, while the added installation of solar panels on the roof provides not only a Zero Energy Building, but a Positive Energy Building.
Rapid construction rate
A 80 m2 sandwich panel house can be built on turnkey basis in only 1.5 months. The assembly of the case of such a building comprises up to 10 days. All supplied materials are prefabricated and further assembled on site as per the assembly instructions and engineering charts.
Full-set delivery
Rauta’s frameless construction technology provides for the turnkey erection of a sandwich panel house, including design, foundations construction, as well as delivery and assembly of all required materials. As the result, the client receives a house ready to be furnished and occupied.
The delivery set may include sandwich panels, fasteners and additional elements, windows, doors, roofing, as well as materials for external and internal finishing. As required, it is also possible to build foundations and equip the house with services: water supply, sewage, heating, ventilation, electrical cabling, lightning protection etc.
Optimal cost
The cost of a sandwich panel house depends on its area, foundation type, the specifics of engineering services, and finishing requirements etc.
Rauta offers several finished options:
| Set delivered to the site | Price without assembly, from €/m2* | Price with assembly, from €/m2* |
| Standard house set (flooring, walls, partitions, roofing, finishing accessories, and fixings) | 545 | 635 |
| House set with options (standard house set + lightning protection, windows, and doors) | 610 | 715 |
| Turnkey basis sandwich panel house (house set with options + foundation, engineering services, and internal finish) | 850 | 1145 |
| Solar power station set (solar panels, inverter, accessories) | 100 | 150 |
* prices current at the time of the writing of the article for a typical cottage with an area of 80 m2
An assembly manual, process chart, all the required certificates, test reports, and warranty are provided at delivery of a house set.
Reliability
With Rauta frameless construction technology, sandwich panels are the load bearing elements transferring all of the weight (dead weight, operating weight, wind and snow loads) to the foundation. This solution is the most efficient in the construction of single-story buildings with up to 4 m spans in internal premises.
Sandwich panel houses fully meet current construction norms in terms of strength and stability and are on the same level with the classical construction technologies. The load-bearing capacity of all elements is confirmed by engineering calculations and test reports.. The rigidity of the building structure is ensured by well-designed placements of partitions, connections, and junction units, which guarantees its seismic stability during earthquakes of up to 7 points.
Ruukki sandwich panels have passed tests conducted in accordance with the Scandinavian standard SSF 1047 on burglar protection for walls and ensure a high security level corresponding to burglar protection class 2, and protection class 3 in case of additional cladding.
Durability
The long life of a building is primarily ensured by the characteristics of sandwich panels. High-quality sandwich panels by Finnish company Ruukki are manufactured of S280 grade European structural steel with 190-275 g/m2 zinc coating and a polyisocyanurate core with compressive strength of over 100 kPa.
Ruukki panels have a warranty period of up to 30 years and a useful life of over 50 years.
The building envelope structures are made of sustainable materials, which is confirmed by their EPD as well as LEED and BREEAM certificates.
Operational compatibility
All elements of a house are manufactured on modern equipment and supplied to the site fully complete, including necessary accessories and fixings. This guarantees the precise geometrical characteristics of each element and minimizes the need to additionally fit structures on site, thus considerably decreasing the construction period and increasing the construction quality.
A Variety of Finishing Options
A sandwich panel house can be used without additional external and internal finishes: the steel facing of sandwich panels has an esthetic appearance and is resistant to atmospheric precipitation. Panel facing can be smooth or have linear profiling and is available in all RAL colors.
If desired, the building facade can be additionally clad with virtually any materials: timber, brick, metal cassette panels, lamellas, designer and folded profiles, ceramic granite, natural stone, HPL, composite aluminium panels, etc.
In the interior of the house, one can use plasterboard with final finishes: paint, wallpaper, tiling, etc. To eliminate the possible thermal expansion of the sandwich panel steel facing, it is recommended that the plasterboard sheets are installed onto a profile frame.
A broad range of planning solutions
A rectangle is the maximum efficient shape of a frameless sandwich panel house and its internal premises. This provides elegant design and ensures the best functionality of premises. The interior space’s usage efficiency increases as a result of well-designed planning solutions without corridors.
If the recommendations on the width of spans between the bearing walls are observed, the building can be of virtually any size. The concept of rectangular shapes allows a modular combination of the building interior space without restrictions in terms of the number and size of the premises.
Typical projects of sandwich panel houses
Expansion Options
The rectangular shape of a building and the simplicity of the sandwich panel junction units enable the easy addition of new premises in any convenient location as required.
Mobility
All junctions of the building’s structures are mechanical, and thus, when necessary, a building can be disassembled, moved to another place and re-assembled using the same parts.
Low weight
The specific weight of the structures of a house comprises 100 kg/m2, with maximum weight of one element being up to 80 kg. This enables manual assembly of a house without cranes.
All-weather assembly
All elements of a building are supplied in hermetic packing and can be stored on an open site. The Installation of structures does not require wet processes, and hence can be performed in virtually any weather conditions.
Assembly in congested conditions
The compact dimensions of the elements (maximum length up to 4.5 m) enable their storage within a building, while sandwich panels themselves may be stored in their packaging and placed in stacks. The minimum requirement for storage area, as well as the absence of hoisting mechanisms on site enable quick and convenient assembly in small areas.
Foundation
If a sandwich panel building is used as a temporary structure, it may be installed onto a hard even surface (asphalt or crushed stone base) with water drainage along the perimeter but without a separate foundation.
The construction of capital buildings requires a foundation to increase the stability and the installation of engineering services, as well as to increase the life of structures. Depending on geological conditions, the base can be a slabs (1) monolithic or blockwork striped foundation (2), post footing (3) or piles (4).
Flooring
To ensure a closed heating circuit, 120-200 mm thick PIR core sandwich panels are used as the flooring base.
The finished flooring is laid on an OSB or veneer base. In this case, it is possible to insert engineering services within flooring structures.
Walls and partitions
The external walls of the house and its internal partitions are built of 120-200 mm thick PIR core sandwich panels, ensuring good sound insulation at a 24 dB level. The standard ceiling height without internal finishes comprises 3 m. Plasterboard structures can be applied as non-bearing internal partitions.
Sandwich panel walls have higher sound transmission screens and thus can weaken the Wi-Fi and mobile communications signals within premises. To improve the wireless network operation, it is recommended that Wi-Fi amplifiers be installed in several rooms or to install internet access sockets. The best level of mobile communication is available near windows.
Appliances, furniture, climate equipment, etc. having a weight of up to 50 kg/m2 can be suspended onto the internal facing of sandwich panels. In this case, they shall be fastened directly to the steel facing with the help of screws.
A suspended toilet unit is mounted onto a separate frame made with plasterboard, which is fixed directly to the sandwich panel facing along the whole length of the facing and to its side walls.
It is also possible to use magnet or vacuum pad hooks for hanging lightweight household objects (towels, paintings etc.).
Ceiling and roof
Depending on the selected architectural-planning design, a sandwich panel house can have the following roof types:
Any materials can be used for external cladding: metal tile roofing, corrugated metal, bitumen tiles, folded and design profiles, membranes etc.
Windows and doors
Any type of metal and plastic, aluminium, timber, etc. windows and doors can be used in a frameless house built with sandwich panels.
The most optimal solution is the installation of windows and entrance door having a width of 1,100 mm, a multiple of the sandwich panel size. In this case, windows can have any height within the wall height. Internal doors can have any dimensions and be installed in any location, independent of the layout of sandwich panels.
Heating, ventilation, and air-conditioning
The sandwich panel house structure is very hermetic, moisture- and air-tight; hence, it is very important to provide correct ventilation to create comfortable microclimate within the premises.
The optimal solution to plan for the energy-efficient ventilation of a house is based on the recovery principle. A supply and exhaust recuperator is installed in the attic space, with air ducts placed to supply and circulate the air.
The house air conditioning system can be local, using traditional split systems, the external blocks of which are fixed directly to the outer facing of panels, or multi-zonal, with a separately standing external block.
Almost all contemporary systems can be used for heating the building:
Lightning protection
Static electricity accumulation is possible on the metal surfaces of a building; accordingly the installation of a lightning protection system is recommended for the safety of a sandwich panel building.
The construction of a sandwich panel house requires in-depth knowledge of design, manufacturing structures, and assembly; only an experienced contractor should be hired to build this type of building.
Rauta is the exclusive supplier of Ruukki sandwich panels to Ukraine and has many years of experience in implementing projects for various uses. The experience of the company’s specialists, as well as the availability of developed typical solutions and all the necessary supporting documentation enables the organization of the construction of sandwich panel houses with a high level of quality and within the shortest possible period.
Rauta is an exclusive supplier of Ruukki sandwich panels to Ukraine and has many years of experience in implementation of projects of various use. The experience of the company’s specialists, as well as the availability of developed typical solutions and all the necessary supporting documentation enables organizing construction of sandwich panel cottages with a high level of quality and within the shortest possible timing.
