For Builders and Architects

With more than 10 years experience in designing and manufacturing Passive House windows – and understanding the importance of true integration and quality – we have become knowledgeable partners to architects and builders, not merely suppliers of a building product. From this point of view, we'd like to begin sharing useful specs and facts about how German Passive House requirements impact the performance of our windows.

Achieve the highest comfort level without the support of mechanical systems.

• The key to this requirement is establishing surface window temperatures that are as close to the interior space temperature as possible (within 5°K). This is the basis of Passive House Institute certification.

Provide maximum energy performance.

• The goal here is to achieve the highest resistance to transmission-loss (U-value) while allowing a high level of radiation gain (Si g-value/ US solar heat gain coefficient SHGC), with summertime shading. Overall window performance needs to be U-0.14 or better and standard glass performance U-0.1 and SHGC-53%. This needs to be achieved even in a severe Minnesota winter with little heat, that is, windows should lose less energy then they gain during the day. (Many other glass values are available from Optiwin, so please contact us with your performance expectations.)

Provide a high level of daylight.

• Daylighting is making use of the available daylight and is measured in light transmission value (t-visual). Our standard triple-glass performs in the area of a good double-glass with of light transmission value of 70% or better.

Achieve thermal bridging in frame construction and installation detailing.

• Our frame design, in combination with the ability to install this frame at the appropriate place in the wall assembly, allows for a true integrated approach to achieve the outstanding performance requirements required by the Passive House standard.

Water and air infiltration in frame construction and detailing.

• All Optiwin windows meet the highest tested air infiltration class in Germany and are rated as ‘Class 4’. The minimum value for this class is a the Q-value of 0,75 m“/hm at Q-100.

Shading

• Low SHGC glass can be a sound strategy in most instances to gain the appropriate amount of ‘free/passive’ heat to a building during the wintertime. This requires the incorporation of an appropriate external shading system, which Optiwin offers, by partnering with one of the largest and most experienced manufacturer in the world, Warema.