The fast-growing group has opened three new stores in Wolverhampton, Warrington and Stevenage this year, taking the total number of trading stores in the portfolio to 40 including one at Oldbury.
Early trading in all three stores has been described as excellent.
Another four new stores will open in 2023.
In the year the price per sq ft of occupied space was up 13 per cent driven by continued strong demand for self-storage and good occupancy levels.
Preliminary results for the year will be announced on October 31.
Executive chairman Andrew Jacobs said trading in the year had been excellent with continued strong demand for self-storage across the UK.
"We have made significant progress on our new store pipeline, whilst remaining conservatively geared, including adding a new landmark store site in Bolton, Greater Manchester, in recent weeks. We are on site at four new stores, all of which will open in 2023, accelerating our earnings growth in the future," he added.