2121b1b5_re___AccountingExplanation_com__Reasons
[Sr. No.] (xxxiv) [Nature of Expenditure] Capital expenditure. [Reasons] 
As a slate roof is replaced by a glass roof, it will increase the efficiency of the building and therefore, it is a capital expenditure.
Difference between Capital Expenditure and Revenue Expenditure - AccountingExplanation.com
Reasons