Mesoporous silicoaluminophosphate was assembled from microporous SAPO-5 secondary building unit precursors. The resultant material possessed both mesoporous channel properties and microporous wall properties. The catalyst showed promising results for vapour phase isomerisation of 1-octene. The presence of strong acidic sites favoured the formation of considerable skeletal isomerised products at elevated temperatures (400–450 °C). However, the catalytic conversion remains constant and active for several hours.