One way to save energy is to keep the heat out in the summer (when you are trying to cool the house with A/C and keep the heat in in the winter (when you are trying to heat the house).
Home with large expoanses of glass can bring in light and warmth in the winter but cvan aslo make it expensive for A/C to kleep cool in the summer. Keeping heat out is a great way to keep the A/C bilss and cost down.
" ... to keep out the summer sun and keep your energy bills down, consider making a DIY insulation panel ... using reflective material to keep the scorching sun out ... constructing simple wooden frames and stretching reflecting insulation over them, ... five huge panels cost under $200 and took five hours to build."
Via: LifeHacker LINK