ᐅ Vertical sliding windows / outward-opening windows

For the renovation of an old townhouse with a relatively small floor area (50 sqm (540 sq ft) per floor), I am considering deviating from the standard “windows that open inward” for practical reasons. I quite like the concept of American-style windows, which often open by sliding upwards. This way, I can open the window halfway without losing any interior space. I also find the Scandinavian-style windows, which open outward or rotate, quite interesting.

Does anyone have experience with these types of windows? Apart from more difficult access for cleaning, are there any safety or energy-related reasons against them? Should I generally expect longer lead times when ordering, or does it not really matter since all windows are custom-made anyway?

My neighbors have Norwegian wooden windows, most of which open inward normally. The kitchen windows have a tilt-and-turn mechanism (a lever at the bottom center; you push the window outward at the bottom and the top part tilts inward) – I find this quite practical because you don’t always have to clear your windowsill, which often holds herbs and other items in kitchens, to ventilate. Both doors open outward as well, with a “stay-open” option, which is really great! However, this only works if the areas above are covered (in this case, a carport and a porch). The handles are quite unusual (tilt and fully open positions are reversed compared to ours).

We lived for many years in a half-timbered house with wooden sash windows that all opened outward. Here again, the advantages were decorative items on windowsills, easy handling, nice appearance, a great sense of space, and it felt like there was more room inside – but: with small children, it was very dangerous. If the handle was not fully closed (which can happen because the frames tend to warp slightly) or a little one fiddled with it, and you leaned against the window, it could open unexpectedly. So, we secured all risky windows with cable ties for a long time and rarely opened them. If you leave a window open and it rains, that is very bad for the wood over time, and the window no longer seals properly. That means you can’t leave the window wide open at night if rain is possible. You cannot tilt these windows either because water would run in like a funnel.

I now have wooden windows again, but standard ones. I really missed the tilt function because I like a fresh breeze in my home – that’s why we decided against a controlled mechanical ventilation system...

Sliding windows are still quite common in the Netherlands. I would suggest looking for manufacturers or suppliers there.

-LotteS- schrieb:

With small children, this is really dangerous. If the window handle isn’t fully closed (this can happen because they can warp slightly) or if a little one fiddles with it and you lean against the window, it might open unexpectedly. So, we secured all risky windows with zip ties for a long time and only opened them rarely. If you leave a window open and it rains, that is very bad for the wood over time and it won’t seal properly anymore. That means: leaving windows wide open overnight is not an option if rain is possible. You cannot tilt these windows, because then water would pour in like through a funnel.

Those are two good points, thanks! For ventilation, I’m planning a central ventilation system, so I hope I won’t have to keep windows open constantly, day or night (and I’ll also get a pollen filter).

Regarding safety, I’m leaning towards vertical sliding windows. The question is whether the mullion at eye level is a dealbreaker. I never found it bothersome in the US, but I have never stayed in such rooms for more than a few days.

For the upper floors, there will be fall protection installed on the exterior facade anyway. When the windows are slid up, this also protects the teenagers in the house (but that applies to conventional windows as well).