I have windows getting direct morning sunlight on one side of our apartment, and direct evening sunlight on the other side. All windows have (wooden slat) blinds.

I was wondering: what is the best way to keep the inside of the apartment cool during hot summer days, and warm during cold winter days, just by using the windows and blinds, to avoid using energy-hungry devices? That should be achieved by opening and closing windows, and opening and closing the blinds, in order to control airflow and exposure to direct sunlight. Generalising for most homes would be great too.

Note: this is a rented apartment.

  • 1
    This is not in the scope of your question, but have you considered planting trees on the side corresponding to the hottest time of day?
    – user2451
    Nov 24, 2016 at 16:05
  • We are renting, which makes it trickier to do it because of (1) the owner having the last word and (2) the limited time we might spend here.
    – stragu
    Nov 28, 2016 at 1:14

1 Answer 1


During summer, the first thing you would want to do is to limit the amount of sunlight entering the windows when the sun is shine on each side of the house.

If you can put something on the outside of the windows (like shutters) to protect the windows from the sun that would be ideal. If that is not possible then close the binds you currently have.

At the same time, open the windows on the opposite side of house; the air outside the house will be in the shadow of the house & hence cooler than the air on the sunny side of the house, which will be heated by the sun. Keep the windows on the sunny side of the house shut.

During winter, do the opposite concerning the blinds, open them up as much as possible on the sunny side of the house to let the sun light in, but close the blinds on the other side of the house as that will reduce heat loss. Regarding the windows, keep them closed as much as possible.

If possible, plant deciduous plants (trees or vines) to shade the windows during summer. The foliage will provide shade during summer and during winter, when the plant has no leaves, they will let the sun shine into the windows to assist with warming.

  • 1
    To add, during summer, throw everything wide open in the early morning to allow the air to cool the interior. Only when the sun starts gaining strength do you close the shades on the sunny side.
    – user2451
    Nov 24, 2016 at 16:04
  • 1
    Depending on security and pest concerns, open windows at night (or in the evening if the temperature drops early enough) can make a huge difference (summer).
    – Chris H
    Nov 26, 2016 at 19:07
  • 1
    White blinds will do a better job of reflecting incoming light than wood slats by roughly a factor of 2. Nov 26, 2016 at 19:09
  • I know one person who bought panels of foil sided beaver board (very lightweight sawdust board) cut them to fit the window and in summer leaves those in place during the day. They are light enough that moving them daily isn't a big deal. Another person uses aluminum coated mylar (space blankets) as drape liners. Nov 26, 2016 at 19:11

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.