We are in the midst of a region-wide, if not nation-wide, house retrofit. While it may be something of an oversimplification to state, the basic truth is that in the old days (like pre-1940) fuel was cheap and houses leaky. Today fuel is not only dear but comes with myriad external costs particularly environmental impact.
Retrofitting old houses to be tighter and more energy efficient is big business and often a costly and/or labor intensive proposition. While I am far from an expert on the subject (indeed I’m quite callow) saving fuel has been a preoccupation these past few months and my education has been rapid.
There are two basic ways to prevent heat loss: 1) Insulate 2) Seal. Recent building science research has placed increased importance on the latter, in other words if the thing you are heating is tight, the amount of insulation is of less importance.
Consider a cold windy day. You have a choice between a thick wool jacket and a yellow rain slicker. While the wool insulates well the wind whips right through it. Brrrr. On the other hand, the yellow slicker (“skin” in fisherman talk) has almost no insulation but blocks wind almost completely as it retains body heat (i.e., it is not “breathable”) the problem is that it also blocks moisture and can lead to overheating and sweating. Yuck.
Which brings me to shower curtains. Meat lockers employ large strips of vinyl to cordon of cold areas where doors are not practical. Areas of a house can like-wise be isolated from one another with curtains, the temperature differences from one side of a strategically placed curtain to the other can be in excess of ten degrees. Naturally the thicker the curtain the better the barrier but even a thin bed sheet will make a dramatic difference.
Entryways, stairwells, windows, and especially the area around the thermostat (assuming you have just one “zone”) all lend themselves to being zoned-off if heat is not desired in certain parts of the house. The idea is to keep the heat from reaching the leaky parts of the house.
The advantage of shower curtains is of course that they are transparent. This makes them well suited for windows. Shrink-wrapping widows stops the air from flowing in but it doesn’t much help the heat from being sucked out (that cold feeling you get my widows is heat loss). A clear shower curtain between the shrink wrap and a summer curtain gives an extra layer of heat retention while still allowing natural light to shine in.
While shower curtains may not be every decorators dream, there are quite a few nice ones out there, and even at $35 it is still a lot cheaper than new windows.