Followings are the dimensions of economically developed Outdoor Housing Cases for the CCTV Cameras;

Small size: 80(W) x 70(H) x 260(D) mm
Medium size: 103(W) x 98(H) x 370(D) mm
Large size: 142(W) x 115(H) x 392(D) mm

Professional Cameras should be mounted in medium or large size housing cases and Web Cameras in large size ones. A heater and/or blower can be built into medium or large size housing case. When a heater and/or blower is built-in, the available inside depth length is reduced by about 40 to 50mm. A heater and/or blower is usually required to be powered separately by 110VAC or 24VAC. And, you need an outdoor mounting brackets for the housing cases.

Other special housing cases such as dome camera housings, triangular ceiling or corner mount housings, elevator-cab housings, explosion-proof housings are usually expensive.