Zola's Product Lines
Zola offers a variety of window lines to suit your needs and budget.
Zola's Classic Wood window. The standard wood window in Germany, Switzerland and Austria features a 68mm (2 3/4") Meranti wood frame and European high performance double glazing. The frame is fully factory finished in paint or stain to ensure longevity and beauty.
Classic Wood can also be milled to in our beautiful Heritage line to match the style of historic buildings.
Zola's Classic Wood window, plus our rain screen aluminum cladding for decades of virtually maintenance free service life. The wood frame is made from fully finished pine wood (choose between finger jointed for sustainability or clear for the best looks). The aluminum cladding is available in three different profiles (Heritage, Classic and our modern Quadrat) and is powder coated in one of over twenty colors.
Zola's Thermo uPVC is the lowest cost high performance window available. Made with the same high performance triple glazing as the rest of Zola's Thermo line, but at a 25% lower cost than the wood version. The uPVC frames come standard in white, but can be finished in a solid color or wood look for an additional charge.
Zola's Thermo Wood, our 88mm (3.5") deep Meranti wood window, offers great thermal performance and beautiful craftsmanship at an affordable price. Triple glazing with a U-value of only 0.09 BTU/hr.ft2 saves energy while maintaining a high SHGC value of 0.48 – 0.6 and a visible light transmission of 71%. Meranti wood, combined with our three layer waterborne factory finish offers superior finish durability, while German Roto hardware ensures the window operates smoothly.
Zola's Thermo Clad adds our rain screen aluminum cladding to the Thermo line. The wood frame is made from 88mm (3.5") fully finished laminated Pine (choose clear or finger jointed). Triple glazing with a U-value of only 0.09 BTU/hr.ft2 saves energy while maintaining a high SHGC value of 0.48 – 0.6 and a visible light transmission of 71%. The aluminum cladding is virtually maintenance free for decades, while German Roto hardware ensures the window operates smoothly.
Zola's ThermoPlus Clad is our best selling window, engineered for the Passive House market. Based on the Zola Thermo Clad, PLUS adds a fully integrated layer of patented German Purenit insulation in frame and sash. The result is a window that got fantastic lab test results (like an overall U-value of only 0.123 BTU/hr.ft2) while maintaining a sleek, elegant appearance and a highly competitive price in its class.
Making Zola a Successful Part of Your Project
With a few tricks, Zola can be more economical, less hassle, and better performing – read why:
The most beautiful projects we do contact us already in the design phase. They also end up being the most economical ones. While Zola does not have any standard sizes, some sizes carry a lower per square foot cost than others. This is because a large part of the cost of our windows is labor, and there is the same amount of labor involved whether we build a small or a big window. Also consider that European windows have wider frames – larger units look better and more elegant in proportion. So how big should one go?
Tilt & Turn units can be up to 25ft2 per sash, with a max width of 5ft. Our 5'x5' Tilt&Turn is a bestseller. A French Tilt&Turn window, with two leaves, could be 10' wide and 5' high, or 6' wide and 8' high.
Fixed windows can be 8'x11' per glass pane in our standard system. Bigger is possible, but carries a price premium.
For doors, read on under "Doors ad Sliders"
So what does this mean to your design? If the budget is tight, combine smaller windows into less, larger ones. One 5'x5' Tilt&Turn can make a bedroom great. If it shall be spectacular, add a large fixed pane.
If your design is modern, less divisions and frames in the way will make it even more striking.
We generally recommend Patio doors, often as a double door, for openings up to seven feet. In comparison to a slider, you have twice the clear opening, and the cost is lower.
For openings from 7' to 11', many architects opt for an OX Tilt-Slide unit. A great air seal and the option o using the tilt function for night ventilation make this unit successful.
Lift-Slide doors are the most luxurious of sliding doors, and especially suited for large openings over twelve feet. Each glass pane can be up to ten feet wide, allowing us to build 20' OX units. A large part of the cost is in the hardware and assembly, making large lift-slides not much more than small ones.
Breeze Panels, our folding glass walls, are a good choice for any opening width from 7' to 25'. Cost is proportional to width for Breeze Panels.
Aluminum Clad units are virtually maintenance free, while wood windows will need to be repainted at regular intervals over the course of their life. With proper care, a wood window can last as long as a clad one. How often repainting is necessary will depend mainly on the intensity of the UV at your site. In Germany, repainting within the first ten years is rare. In high-altitude, sunny Colorado it may be much sooner.
Zola's sister business in Germany sells 90% wood windows, while Zola sells over 90% clad windows in the U.S.
From a cost standpoint, all wood units, even when made from Meranti, are much more affordable – the clad surcharge is about 35% in the classic line and 20% in the Thermo line.
We can build windows in any shape. In an all wood window, the options are endless, in a clad unit there are some limitation to the radius we can achieve.
We have built windows with a succession of curves, basket arches, trapezoids – just send us a precise CAD-file or full scale template.
Through our sister company in Germany we gained a lot of experience with simulated divided lites and muntin bars, especially on listed historic buildings. Both our wood and clad units are available with fine, 7/8" wide muntin bars, with historically correct milling profiles. These are made from a wood piece glued on the inside, a wood or aluminum piece on the outside, and optionally a spacer bar between the glass panes, making the simulate divided lite look absolutely real.
For window units that need to achieve the look of a classic double hung, we recommend using one large tilt&turn window with a true glass dividing bar across the center, and additional munitions as needed for the design.
Please plan on ordering your windows early.
Our production time is eight weeks after we receive your deposit, plus shipping time by container, which will be three to five weeks to the lower 48.
It is highly recommended to submit your order to us by the time you break ground on your project.
Zola offers custom installation details on request, or download typical conditions from our library here.
The 2×4 wall with OSB board and a TJI hung on the outside is a favorite among passive house designers and offers great thermal performance as well as many excellent options for installing a Zola Window.
The 2×6 wall with a layer of exterior foam is a common choice for high performance homes and combines very well with over insulating the window frame.
Zola Windows have also been successfully installed in straw bale houses – and energy modeling was used to predict the installed performance.
Many retrofits have used Zola windows on brownstone restorations
Sliding Doors and Breeze Panels
There is more than one way to glaze a big opening.
For large openings, Zola offers three different solutions. Tilt-Slide Doors are economical and highly energy efficient. They tilt inside and the glide to the side like a minivan door. For low threshold applications and the largest glass panes, we recommend lift slide doors. Finally, if you want to open your house completely to the outside, consider a Breeze Panel Folding Glass Wall.
Tilt slide doors are a great option for highly air-tight and energy efficient sliding doors. They are mainly used in OX configurations between eight and eleven feet in width, but OXXO configurations of twenty feet or more are also available. One drawback of Tilt-Slide units is that there is no low threshold option, and some hardware is exposed to the inside.
Lift-Slide Doors are the premium sliders available, offering the widest expanses of glass for unbelievably beautiful openings. Our completely assembled doors can be twenty feet wide and eight feet high, made of only two large glass panes. Larger sizes are available, but site assembly may be required.
Lift-Slides lift out of their seals at the turn of the handle, and the slide effortlessly with just a few fingers. They feature a very low threshold that can be embedded into the floor.
Breeze Panel Folding Glass Walls allow you to open up your house completely to the outside. The panels fold and stack to the side, out of the way and out of your view. As with all our products, all units are custom sized, but with Breeze Panels we are able to offer especially large sizes and custom solutions.
Balcony, Terrace and Entrance Doors
We have several options available for glass doors. The most economical option is the Balcony Door, which can be used for unit sizes up to 36" wide if no outside lock is required. For larger units, terrace doors are a stronger, reinforced version that can be over 4' wide per sash and offer either tilt and turn or traditional locked entry keysets.
Note that for the main entrance door to any unit you need to specify an entrance door, which is our strongest type of door and built for the heavy use as a main door.
Balcony doors are the most economical of doors and operate as tilt & turn units. In effect, these are door-sized windows with a reinforced lower sash frame and low threshold options. With a slim 88mm frame, these doors can be very energy efficient. The limitations are a maximum 3' unit width and no option for an outside lock. Balcony doors click shut, but can be pushed open from the outside by gentle pressure. On the inside, they feature a regular window handle – in the down position, the door is locked, horizontal is unlocked, and up is for tilting the unit.
Terrace doors feature a wider stile, 105mm instead of 88mm like on balcony doors. This allows for wider sash widths of about 4' per sash (a double door can be 8') and a variety of hardware options. We can now use either tilt&turn hardware or a regular door handle (without tilt function) and both can be combined with a lock set – keyed outside and thumb drive inside. Terrace doors can turn out for an upcharge.
Entrance Doors feature an even wider stile of 120mm for the heavy duty use of a main door. Performance is best and price lowest for full glass doors, but we can also insert a recessed panel or build a modern, completely flush door. We have two options for the sill, either our very low thermally broken single sealed Dafa threshold or our slightly higher, but dual-sealed Weser threshold. All entry doors come complete with lock sets and keys.
Ordering, Delivery and Installation
We try our best to make it easy for you.
Selecting the right windows and getting a quote is easy with Zola. You can either contact your local rep or Architect and Passive House consultant Florian Speier, owner of Zola Windows, directly – either though our contact page where you can immediately upload your drawings and window schedule, or by phone at (303) 578-0001. Zola's headquarters are located in Boulder, Colorado, but we manufacture at our contract facility in Europe and ship directly to our customers in the U.S. and Canada.
When you submit a quote request, please include your phone number so we can call you to clarify details or propose some value engineering, and don't forget your address so we can ship samples out to you. Most quotes will be ready in less than a week, but if your project is on a tight deadline please let us know and we will do our best to quote it quickly.
Once we have finalized every detail and received your order and down payment, we will manufacture your windows and doors and ship them directly to your site. Please be advised that the typical lead time from order to delivery is thirteen weeks.
Shipping is one flat rate fee for deliveries to the U.S. and Canada, no matter how much you order – we will deliver a container directly to your job site. This ensures that there is minimal risk of damage during transport, and lets us plot the route for your windows carefully to make sure there are no unnecessary altitude gains or losses to ensure no argon gets lost. For high altitude locations, our Altimeter system works wonders to carefully release excess argon without letting air back in, as conventional breather tubes do.
Zola does not offer installation services, but we work with you to develop the appropriate install detail for your application, budget, and contractor preferences. We also have a library of PSI-install calculations for different wall types for passive house clients. Zola clients can order the selected installation materials such as bolts, brackets, tapes and gaskets directly at discounted prices.
Zola Install Guide (PDF)