You can make a cheap and easy brooder box out of three large moving boxes sold at Lowes. First take two of the moving boxes and slit them both down one corner. Then duct tape the two boxes together to make one huge box. Close the flaps on the bottom. It should now look a little like a refrigerator box. Secure all weak and movable areas with the tape. The end of your brooder box should be the widest side of the original rectangle moving box. Make a solid bottom for the brooder box by cutting a large section from the third moving box. Cut to fit snugly the floor of the brooder box.
For the first week or two turn the top flaps inward to help make cleaning a breeze. Tape the flaps up to make the sides taller when the chicks start trying out their wings. After about 2 weeks, I covered most of our box with a large window screen from our office window.
Hang the brooder lamp above one end of the box by a large hook and use wire clips to hold it secure. Raising and lowering the lamp gives more or less heat to the chicks as needed. Line the bottom of the box with a shallow covering of pine shavings. Place a thermometer directly under the lamp on top of the pine shavings. For the first week your thermometer should read 95 degrees, the second 90 degrees, the third 85 degrees, and the forth 80 degrees. Place water at the opposite end of the box from the light and food at about the middle of the box. Offering a small container of chick grit is also a good idea as they are growing.
This large broader box gives the chicks plenty of room for exercise, elbow room to help settle disputes, and a way to get away from the heat if they are too hot.
Below is a picture of our brooder box after a few weeks of use. It doesn’t look as crisp and nice as when we first made it but at least it gives you an idea of what is described above.