If the power is going to be out for a long time, buy dry or block ice to keep the refrigerator as cold as possible. Fifty pounds of dry ice should keep a fully-stocked 18-cubic-feet freezer cold for two days.
Instructions. Measure the width of the window and decide how wide the window treatments will be. Window valances should extend 2 inches beyond the window frame to allow for the support brackets. Being made of wood, box valances weigh more than fabric valances, so consider how they will be attached to the wall.
Measure the window frame and ADD 3 or 4 inches. Valance Over Drapery or Curtain. Add 4 inches to the width of your drapery or curtain. The result is your valance width. Some notes on height. Things get a little more complicated when discussing how high to install your curtain or drapery rods.