WO3 is an important technological material with wide usage in gas-sensing devices but its low temperature phases are still mysterious. There are conflicting reports in the literature and new predictions from Density Functional Theory calculations which motivate us to clarify the situation experimentally using HRPD. We will investigate the structure between room temperature and 5 K to clarify the phase transitions and detailed nature of the structural distortions. This will allow us to understand better the driving mechanisms behins structural changes in WO3 and therefore also the fascinating and useful physical properties it hosts.