The standard rough opening for a shower is the size of the frame that must be built before inserting your shower. The standard sizes are:
* 36 inches wide x 72 inches high (91 cm x 183 cm)
* 32 inches wide x 72 inches high (81 cm x 183 cm)
It is important to measure and build the correct sized frame before installing a new shower, as it will need to fit correctly into the space available.