Permanently affixing something useful to a house or the ground violates the Torah prohibition of Boneh. Removing such fixtures violates the Torah prohibition of Soter. This is the case even if the attachment is not tight and the objects can easily be detached and reattached, as is the case with hinged or sliding windows or doors. Since these are permanently attached to the house, they become part of it, and installing them or removing them is a transgression of a Torah prohibition. Therefore, even if a room is hot, one may not remove a window from the wall or from its frame (Shabbat 122b; SA 308:9; MB ad loc. 39). Similarly, one may not attach or detach a filter that is screwed onto a faucet, rubber pipes attached to the sink, or light bulbs screwed into their sockets, since their attachment to the house is permanent. Similarly, pounding a nail into the wall or gluing a hook to the wall violates a Torah prohibition, since these additions are permanent (Shabbat 103a; MB 314:8).
One may similarly not attach curtain hooks to a curtain track or the curtains themselves to the hooks on the track. Fastening a curtain rod to brackets that protrude from the wall is also prohibited. Even though all these attachments are loose, since the items are being attached to the building, these actions are prohibited by Torah law. If the rod is not truly attached to the brackets, but rather simply rests upon or inside them and can move back and forth easily, then the rod may be placed on the brackets. In such a case, one may also thread the loops at the top of the curtain through the rod.
If the object being attached to the house or the ground will not last long, the prohibition is rabbinic. For example, it is only rabbinically forbidden to attach a vacuum hook to a wall, since its suction cup will not keep the hook anchored for long.
When something may not be attached to the ground or a house, it is also forbidden to tighten its existing attachment. Therefore, one may not tighten the loose screws of a sink, door handle, or closet handle.
In contrast, objects that are not really attached and do not become part of the house may be put up or taken down. For example, one may hang a picture on a nail, because the picture is not considered part of the wall. If a window breaks and cold wind is blowing through the house, the broken window may be covered with cloth to keep out the wind. This is because the cloth does not become part of the wall, but is placed there only temporarily (MB 313:3 and 315:7; SSK 23:41 and 23:44). Similarly, one may stick papers to a refrigerator using magnets, because the magnets are not considered part of the refrigerator. For the same reason, one may hang a colander over the lip of the sink. Inserting a plug in a socket or removing it is also not considered Boneh or Soter, because the plug is not considered part of the house.[2]
It is self-evident that one may open and close doors, windows, and faucets. This is the case even when the door is not usually opened, or when the faucet in question is the water main, which is rarely shut off. Since they remain attached to the building and this type of opening or closing is the way they are normally used, it is not considered Boneh or Soter. Similarly, one may open and close a porch’s sliding roof that is attached with hinges or that slides on a track, as it is considered the same as a window (Rema 626:3).
It is prohibited by Torah law to use a nail or a screw to reattach a door handle that has fallen off. Reattaching it without a nail or a screw in a way that joins the handles of both sides of the door to each other is rabbinically prohibited, since the attachment is only temporary. In contrast, one may insert one of the two handles into the door without using nails or screws. This is not considered an attachment at all, since the handle is just resting there with nothing to support it. However, there is still a concern that one might forget that it is Shabbat and decide to reattach it properly with nails. Therefore, the door handle should be replaced awkwardly, tilted upward or downward, so there is no concern that anyone will tighten the connection. A handle that has begun to come loose from its attachment to the corresponding handle may not be pushed back into place.[3]
[2]. Some are stringent in the case of a plug that is plugged or unplugged only infrequently, such as a refrigerator plug (Ĥut Shani 36:1). However, it would seem that all plugs should be treated in the same way, since plugs in general are plugged and unplugged frequently. Furthermore, their primary connection is to the electrical appliance, and thus they are not considered part of the wall. (See SSK 13:33, n. 112; Orĥot Shabbat 8:17; Menuĥat Ahava 1:24:20.) However, because a plug is muktzeh, it should be grasped using a shinui.
[3]. If the handle had already fallen off multiple times before Shabbat, and everyone is accustomed to using the door with only one of the two handles attached, one may push that one handle back into its normal place, with no awkwardness (Menuĥat Ahava vol. 3 ch. 23 n. 71). The permissive rationale of attaching it awkwardly is cited in Ĥut Shani 36:4:7. When it is impossible to insert even one handle, one may open the door with the help of a screwdriver or the like (SSK 23:37). Water tanks, septic tanks, and electrical or telephone junction panels boxes are considered part of the building, and thus it is rabbinically prohibited to place a permanent cover on such a structure or to open such a cover. If the tank’s cover has a handle, one may open and close it on Shabbat (Shabbat 126b; SA 308:10; MB ad loc. 42; SSK ch. 23 n. 146).
