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.

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-52% up to 64%. 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 Tanner Windows and Doors, so please contact us with your performance expectations.)

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.

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.

All Tanner Windows and Doors 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.

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 Tanner Windows and Doors offers. Please contact us for more information.

We deliver any size and form that is technically feasible. Limiting factors to this equation are: hardware, insulated glass size units, manufacturing limitations, transportation, handling and installation. Send us your project ideas and we will present possible solutions.

We work with appropriate and high-quality material. We believe in sustainability and doing the right thing. This means we use wood that is structurally sound and can be used for windows and doors. We also use windows that are constructed with limited finger joints (interior layers only are finger-joined wood), and the outer layer is always made up to 4-meter (14ft) of clear solid wood. We typically buy sustainably harvested wood and can provide you with the respective certification. *Please know: We do NOT use rainforest-protected species. Here is a list of wood species we can use: European Fir is our standard wood, European Larch, European and American Oak, American Hemlock, Douglas Pine, Walnut, Maple, Cherrie and Tropical Meranti, Teak and Sipo Mahogany*.

We paint, stain or just oil our wood at the factory, prior to assembly. This means that our 3-/ 4-coat of factory finish is throughout and we believe is better than any site-applied finish. This leaves the challenge to protect the finish to the contractor at the site during the long period of construction after the windows and doors have been installed.

Handles and knobs are produced in stainless steel, brass, aluminum or any other finish requested and available as long they are compatible with the European hinge and locking hardware.

Various locking and security systems are also available.

The same holds true to opening, locking, etc. motors, controls and a lengthy list of security controls and interfaces.

Mullion (wood dividers in glass), screens, stain glass are just a few other unique features that are also possible. Contact us if you’re interested in learning more!