Honka Lumi – a plastered log house for the city
PRESS RELEASE 11.7.2013
The modern Honka Lumi show house that Honka is displaying at the Housing fair is a 161m²-log-framed residential house. Its facade is covered with white plaster. The Honka Lumi house presents a new kind of wall structure significantly more energy-efficient than a traditional log house, in which massive wood can be combined with a plastered outer surface.
A log house for a stone house town planning area
Honka’s plastered show house, Honka Lumi, is a massive wood house with a Honka Fusion structure and a frame that is a Honka innovation – the only non-settling log frame on the market.
The Honka Fusion log wall structure limitlessly combines plastering, steel, stone and large window panes as separate surfaces with massive wood. This is possible because the characteristic of a normal laminated log structure, settling, does not need to be taken into account. Honka has been building Fusion houses in Central Europe and Finland since 2000.
”Now construction of a log house in a stone house town planning area is also possible. For more than 10 years we at Honka have been researching and developing the Honka Fusion concept based on a non-settling log structure, together with VTT Technical Research Centre of Finland and Tampere University of Technology. The non-settling log enables understated details that suit an urban environment, such as narrow window frames and simple connections between different materials. At the same time, the best features of a traditional log house, such as healthy indoor air and a long-lasting safe home are preserved,” says Tanja Rytkönen-Romppanen, Honka’s Vice President, Design.
”Based on our experiences, people who suffer from allergies and asthma feel well when they live in log houses,” Rytkönen-Romppanen continues. A breathing log structure naturally balances variations in indoor air humidity, and keeps the humidity of internal air at a suitable level all year round. When the relative humidity in a room remains stable between 30% and 55%, this is good for humans but bad for the growth of microbes, bacteria and fungal spores harmful to health.
Plastering one facade alternative for a Honka Fusion™ house
The facade of the Honka Lumi house was done with plaster covered insulation, the development work for which was done in co-operation with the Tampere University of Technology. Outside the log frame of the Honka Lumi house made of 128 mm logs, a 200mm-thick layer of EPS insulation was fitted, which was plastered using the thin plastering method. The customer can freely select the colour scheme for the facade.
”The key thing in the insulation-plastered structure is that the external skin and insulation protect the wall structure from the effects of rain, so that rainwater cannot get into the log frame. When correctly built, in Finnish conditions the structure is an effective alternative from a perspective of moisture technology in conjunction with a log structure. The log structure must also be virtually non-settling and, in this, Honka already has a solution,” says Juha Vinha, Professor of Building Physics at Tampere University of Technology.
Insulation-plastered Honka Fusion house more energy-efficient
According to studies, the benefits of an insulation-plastered massive wood house are moisture safety, healthy internal air and considerably better energy efficiency than a traditional log house. The U value that indicates energy efficiency is 0.14W/m²K in the Honka Lumi house with a layer of insulation 200 mm thick, which is 18% better than in a house that is in accordance with regulations. An insulation-plastered log-framed house can even achieve the U-value of a passive house (0.09 W/m²K), if the insulation is 300 mm thick.
Wooden house construction on the rise as ecological and healthy life styles proliferate
Architect Tanja Rytkönen-Romppanen, Honka’s Vice President, Design in charge of product development and planning the range of models, has been closely following the development of wood construction for the past 20 years. She has noticed that the trend towards wooden house construction is now on the rise, because ecological and healthy life styles are now ‘in’.
”From an ecological point of view, a massive wood house is in a completely different class from other building materials, because wood is a renewable natural resource and absorbs carbon dioxide in the atmosphere. The amount of energy needed to manufacture a massive wood house is also a great deal less. The woodchips left over from machining the logs are used in the production of district heating,” she explains.
Honka’s range has seven new Honka Fusion houses suitable for an urban environment, and the architectural freedom offered by the Fusion concept has been utilised in their design.