The biggest advantage of an apartment (residential) veranda folding door is space efficiency. You can use both the effects of expansion and non-expansion.

You can use a wider living room if you expand it, but it's too much to block the outside temperature of hot summer and cold winter with just the outside shot window. Eventually, outside temperatures flow into the living room, and the energy loss of cooling and heating is huge.

Folding door to make sure you're worried about it!

When the weather is good or necessary, you can open and close as much space as you want. The maximum 90~95% opening and closing rate can be seen.

This opening and closing rate also has an excellent effect on indoor air circulation. When the windows are tightly closed and the indoor air becomes stuffy, cooked, or ventilated, the room air can be circulated quickly with a wide opening. So you can maintain pleasant indoor air.