Your Upstairs and West-Facing Rooms Turn Into an Oven in Summer

If your second floor is hot by mid-afternoon, and that back bedroom with the west window is almost unusable by suppertime, you are not imagining it. Those rooms have the toughest spot in the house, and your windows are usually a big part of why.

The short version: west-facing rooms catch direct sun during the hottest part of the day, and upstairs rooms sit under a baking attic with all the warm air from the rest of the house collecting up there too. Old windows let that heat pour right in. Better windows turn most of it away. Here is why it happens and what actually helps.

Why west-facing rooms get the worst of it

In the morning and at noon, the sun is high in the sky, and your roof overhang shades a lot of it. But in the afternoon the sun drops low in the west and shines in sideways, right through the window. Overhangs do nothing against low sun.

The bad part is the timing. This happens from about 3 p.m. to 7 p.m., which is already the hottest stretch of a Wisconsin summer day. So the room is soaking up direct sun at the exact moment it is hottest outside, and it keeps heating up well into the evening.

Why upstairs makes it even worse

Three things gang up on a second-floor room.

Heat rises, so all the warm air in the house drifts upstairs. The attic above gets extremely hot on a sunny day, and that heat works its way down through the ceiling. And in a lot of homes, the air conditioning just does not push as much cool air to the upstairs rooms as it does downstairs.

Put a west window in an upstairs bedroom and you have all of that at once. That is the room nobody wants to sleep in come July.

How your windows fit in

Older windows, and a lot of cheaper newer ones, do a poor job of blocking the sun’s heat. The sunlight comes through the glass and warms everything it lands on: the floor, the bed, the walls, you. It does this even when the air outside is not that hot.

Here is an easy test. On a hot afternoon, stand next to the window and hold your hand near the glass. If you feel heat coming off it, that window is letting the sun’s heat straight into the room.

What better windows actually do

Today’s good replacement windows have a special coating on the glass that reflects the sun’s heat back outside while still letting the light through. The room stays bright, but most of the heat stays out. Add a second pane of glass and a better seal around the edges, and the window does a far better job of keeping summer heat where it belongs.

For your hot rooms, this is the single biggest fix. It is the difference between a window that soaks up afternoon sun and one that turns most of it away.

We will give you a straight answer

We would rather be honest than oversell. New windows are usually the biggest help for a hot west-facing room, but they are not always the only thing going on. If your attic insulation is thin, or your air conditioning cannot reach the upstairs well, those play a part too. When we take a look, we will tell you what is really driving the heat instead of pretending windows fix everything.