When can my client company be liable to CT at small rate?

New limited company client, shareholders of which are all members of same family, has historically had 2 investment properties earning rent of £50k.

During the year, one property has been sold and the proceeds used to embark on a property development project. Development unfinished at year-end.

Do these circumstances alter the CT rate for the ompany? If not, what would need to happen for the company to enjoy rhe diminishing benefits of the small company rate?

Thanks in advance for your help.