Structures and building allowance

Chapter 5 F6 MCQ2: Cora has always prepared accounts to 31 October. On 1 May 2023 she purchased a building which she brought into use on 1 June 2023. Costs: Land £700,000 Structure and building £550,000 Renovations of building £ 30,000 What is the maximum structure and buildings allowance (SBA) Cora may claim for the year ended 31 October 2023? Ans; Land does not qualify for SBA Renovations - assume take place after and therefore do not qualify for SBA Structure £550,000 x 3% = £16,500 Why is the 550000 not time apportioned as it was brought into use on 1 June 23 and year end is 31 Oct 23??