average cost to build an indoor pool
1 The Pool-the standard size of a common indoor swimming pool is roughly 8'x15' , and it demands a space or room size of at least 11'x18' . 2  According to EndlessPools.com, the cost for such a pool starts at $20,000, but can go as high as $100,000. Safety Measures-locking doors between the swimming pool room and the rest of the house might be part of the building code, but it is also a good idea to consider the installation of subtle door alarms and even a safety cover on the pool as well, which cost around $600 for the most durable model.