Buying a house is probably the biggest purchase normal people ever made in a life. There are many factors the buyer has to consider before signing the offer. Location, price, size, building material, environment, school net, etc are factors most people come up in their mind when they make a purchase. The amount of sunlight the place get is often a factor many people easily overlook. You want to have more sunlight shine on the place in the winter and avoid afternoon heat in the summer.
Even you are aware about the sunlight, most often you can only rely on the not so accurate the general rule of thumbs, like avoid having west facing window and prefer to have south facing windows. If you want to find out the exact amount of sunlight the place gets all year round, technology comes to help.
First, go to Google map and search on the address. Switch to satellite view to pin point the exact location of the house. Compare the satellite photo with the floor map of the house and jot down the orientation of the windows. Then download a sky map software, instead of finding out the stars at night, use it to find out the position of sun during the day. You enter the altitude and longitude of your city and enter the time of the day, then the software will show you where the sun is in the sky. Pick at least a day in each of the four seasons and track the path of sun the in the sky. You will have a pretty good idea how much sunlight the place will gets.
For example, this is the sunlight data of Vancouver on July 1st
| Altitude (° ) | Azimuth (° ) | Time (24h) |
| 0 | 50 | 5:05 |
| 10 | 65 | 6:23 |
| 20 | 78 | 7:31 |
| 30 | 88 | 8:32 |
| 40 | 100 | 9:32 |
| 50 | 118 | 10:43 |
| 60 | 140 | 11:55 |
| 65 | 180 | 13:14 |
| 60 | 213 | 14:23 |
| 50 | 242 | 15:46 |
| 40 | 260 | 16:55 |
| 30 | 270 | 17:50 |
| 20 | 280 | 18:52 |
| 10 | 295 | 20:02 |
| 0 | 310 | 21:19 |
Altitude – how high is the sun. 0° = on the horizon, 90° = right above the head
Azimuth – the bearing of the sun. 0° = North, 90° = East, 180° = South, 270° = West