Just for coffee and cake…..
You know the feeling; you’ve come home from Shul, and would like some coffee and cake. It’s cold outside and warm indoors and you don’t want to open the Sukkah roof wide and create a draught in the whole house. So you open up one side of the Sukkah roof, sit down for a slice of cake, make a Berocho and sip your coffee….Ahhhh. Unbeknown to you, this simple act of only opening one side of the Sukkah roof has rendered the Sukkah totally Pesuloh. A Sukkah can be built to perfection, with all the necessary details to ensure it is faultless, yet by opening the roof on only one side the entire Sukkah is now Pesuloh. The only way it is Kosher is by opening both sides of the roof. This is an extremely widespread situation in Sukkahs in open plan kitchens and morning rooms, in which the structure of the walls is such that the Sukkah being built can only be Kosher when both sides of the roof are opened.
This problem can be avoided by opening both sides of the roof each and every time the Sukkah is being used, and in this particular situation, awareness is the key. But many occasions arise when being able to open only one side of the Sukkah roof would have been ideal, and with some foresight and advance planning, allowance for this possibility could easily have been incorporated and integrated at the development and building stage, making a more comfortable Sukkah experience.

A Sukkah can
be built to
perfection,
with all the
necessary details to ensure it is faultless, yet
by opening the roof on only
one side the
entire Sukkah is now Pesuloh
The reason for this problem becomes apparent when you consider that a Sukkah must have an area of 70 cm2 with at least three walls. In the example pictured here (Figure 1) there are three walls (highlighted in green), each of them are of the correct required Shiur and are in perfect positioning, so that when both sides of the roof are opened the area occupied by the Sukkah is bounded on all three sides by the walls.
However by opening only one side of the Sukkah roof (see Figure 2, Figure 3) the area of the Sukkah is only half the previous size (indicated with blue shading), regardless as to which of the two sides of the roof is opened. The new Sukkah is now Pesuloh as in each case the area of the Sukkah is now no longer bounded by three walls. What would be required here is to keep an extra door closed each time the Sukkah is being used.

In this instance, to keep the rear yard door closed is generally something not too difficult to do. However shutting the second living room door is certainly a hindrance, and would ideally be avoided.

Likewise, a similar problem I was asked about recently, regarding a totally different situation.The Sukkah (Figure 4) had three walls, two of which were relying on the Halochoh of Dofen Akumah, meaning that the walls of the Sukkah, although not directly below the outer perimeter of the Sechach, were within four amos (188cm) of it, and therefore were still considered part of the Sukkah. If they were to be any farther away, the Sukkah would become invalid.
The Sukkah as it was built looked, and is, perfectly Kosher. However, what the homeowner failed to notice was that if at any time only one roof would be opened, he would lose a wall of his Sukkah, as the distance between the wall and the remaining Sechach would then be greater than four Amos. Much to his dismay, he had unknowingly eaten and slept out of the Sukkah many times over the course of Yom Tov

It is in situations like these that professional and competent Halachic guidance could save much aggravation, allowing the homeowner to sit in the Sukkah in comfort, secure in the knowledge that the Sukkah is absolutely Kosher.