Living in Germany, you notice a lot of small engineering innovations that make life easier, like omnidirectional wheels on shopping carts that actually work. One of these innovations in particular stands out, entirely ordinary to Germans, but extraordinary to visitors and newcomers discovering it for the first time: the tilt-and-turn window.

This window is effectively three windows in one: it serves as a fixed window, an inswing casement window and a hopper window.

When the handle of a tilt-and-turn is in the downward position, the window is shut is and locked. Rotate the handle 90 degrees so it points sideways, and you can pull the window open horizontally.

Now comes the twist: push the window back into place, rotate the handle another 90 degrees so it points up, and then pull it back down toward you. The window tilts inward, opening from the top rather than the side. It then locks into place after opening a few inches, resting at an angle. Each method of opening also aligns intuitively with the different handle positions: pull sideways when the handle is horizontal, and pull down when it is vertical. Warning: functionality aside, changing between these different configurations can be habit forming.

So in one configuration, you have a flexible window that swings as you would expect. This orientation also allows for easy cleaning on both sides of the glass while doubling as a good exit window in emergencies.

In the other configuration, the tilt allows in breezes, helps deflect rain and locks into place against potential intrusions. Heat escapes through the top and air enters and exits around the edges, facilitating draft-free ventilation. In other words: you can leave the window open when you are away without worrying too much about security or the weather.

When you switch back to the locked position, you can also feel the multi-point locking mechanisms click into place (up to eight locks depending on the manufacturer). This provides further security and a completely air-tight weather seal, unlike single hung, double hung or sliding windows, all of which are more prone to leaking air or water. When the window is in this closed position, you are also left with an uninterrupted view through a single pane of glass, versus something like a traditional two-piece sash window which may split your view down the center.

Think about the engineering that goes into these things for a moment: a tilt-and-turn opens in two perpendicular directions, requiring hinges for both orientations as well as the mechanical means to engage and disengage each set with the twist of a handle. It is possible (with some effort) to foil the mechanism and get a tilt-and-turn to open incorrectly, pivoting on just one corner connection, but easy to slot back in as well when you are finished willfully abusing your fixture.

But wait, it gets even better: these come as full-sized doors as well. If your narrow back entry has no space for a window next to the door, you can install one of these, then tilt it open to let in a breeze. They are also great for balconies.

And as if all of these functions were not enough already: each of the tilt-and-turn functions is effectively reversible, depending on your design desires and spatial needs. You can, for instance, get a tilt-and-turn that swings outward rather than inward, as well as one that tilts up and out at the bottom, forming an awning.

Originating in Germany and popular in European countries, tilt-and-turns have been around for decades and have slowly made their way further abroad as well. Some countries, however, including the United States, have been slow to adopt them for various reasons.

For starters, there is inertia: architects and builders are used to working with a certain set of familiar and reliable options. Cost may play a part, as these heavily-engineered windows do come with a higher price tag than some of their less-sophisticated counterparts. They also have heavier profiles, so for cases where the functionality would be redundant or excessive, customers looking to maximize light and views may opt for other types. Also, the US has strict codes for commercial buildings that regulate window openings: in most places, a window with a sill lower than three feet high can only open a few inches (though when code calls for an egress window, these are excellent).

There are cultural and architectural factors as well that may have contributed to their relative absence: American Modernism of the 20th Century was obsessed with controlling indoor experiences, from sounds and smells to temperature and breezes. Fixed windows allowed spaces to become fully-regulated, hermetically-sealed environments.

Pushing back against this closed-window trend, many commercial designers and developers today are interested in the benefits of breathing fresh air and giving people more control over their spaces. There is “a growing recognition that giving people individual control over openings in their space can have a positive effect on their experience within a building,” says Jason Jones of Arcsine, our favorite Oakland architecture firm. Operable windows can “even have positive effects on productivity.” Meanwhile, on the residential front, more and more American manufacturers are beginning to make versions of the tilt-and-turn domestically. Between these trends, perhaps this wonderful window will finally become more common in America, but only time will tell.