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Lammin Ikkuna’s journey from carpentry workshop to tech firm – Signal Window brings new dimension to windows


​Five years ago, Lammin Ikkuna set out to solve a problem which had emerged during the construction of passive houses. Low-emissivity windows were disrupting cellphone coverage. The related R&D project set the Häme window-maker on a technology path, which led to the birth of the Signal Window®.

Development path from carpentry workshop to tech firm

"The development of Signal Window began with small steps. As a window maker, we were opening up a new front and began open-mindedly developing the product beyond traditional window making," says Marko Mökkönen, Product Manager at Lammin Ikkunat.

"To improve signal reception, we did a lot of background work and developed a range of technical solutions during the years of R&D. We built facilities, such as our own signal laboratory, in the factory, where we researched various kinds of window, glazing, insulation material etc."

The result was a window technology which, depending on the conditions, can even be ten times more penetrable for cellphone frequencies than ordinary windows.

"We had three main objectives for the product and we achieved them all." Signal Window® is no different to standard windows in terms of its properties or ease of installation. The U value was not impaired and and the additional cost is only around 5–10% compared to a standard installed window, depending on the window's size and properties.

VTT Group and VTT Expert Services Ltd a partner

Lammin Ikkuna has a long tradition of cooperation with VTT and VTT Expert Services Ltd. "We have been testing our windows with VTT since the 1970s and VTT Expert Services Ltd test our products each year."

"During the R&D project, we tested the Signal Window's U-value, or its heat transfer coefficient, on several occasions. The U value is a key property in terms of a window's energy efficiency and indicates how good a window's heat insulation is. The smaller the figure, the better insulated the window. Comparison tests confirmed that the techniques used in the Signal Window affected the product's U value," says Pekka Sipari, a Product Manager at VTT Expert Services Ltd.

"As a customer, we gain major added value when specialists genuinely understand the subject in question and us. We value excellence and localism. In addition, we have been pleasantly surprised by the overall cost-effectiveness of testing in Finland," comments Mökkönen. 

"When embarking on something totally new and unusual, it is difficult to find experts to help you move forward. VTT has a good palette and network of specialists which can provide SMEs with testing solutions, but we can also participate in trouble-shooting where necessary."

What about the future of the Signal Window?

Working telephone and data connections will become a more important part of our daily lives. The Transport and Communications Committee of the Finnish Parliament has proposed that provisions ensuring cellphone coverage be added to the Land Use and Building Act.

The Signal Window was presented at the FinnBuild Fair last autumn. The product was well received.

"This will introduce another, new option in construction, for improving reception. The investment programme for the product will end in the spring and we will be able to start production."

Lammin Ikkuna will continue to develop its technology in the future. "We gain benefits from our own R&D, which we think will provide us with a clear head-start on our competitors," sums up Mökkönen. 

Tel.+358 20 722 7070
Fax+358 20 722 7001

Opening hours 9:00 - 11:00 and 12:00 - 15:00, GMT +2 time zone


P.O. Box 47, FI-02151 Espoo, Finland
Tel. exchange +358 20 722 111
Opening hours Mon - Fri 8:00 - 16:30,
GMT +2 time zone
Fax +358 20 722 7001
Contact us

Tel. +358 20 722 7070
Fax +358 20 722 7001
Opening hours 9:00 - 11:00 and
12:00 - 15:00,
GMT +2 time zone