The Court of Justice held in Promo 54 (C-239/22) that converted old buildings qualify as renovations and thus are subject to VAT taxable if they create added value. This follows directly from the VAT Directive and must be applied regardless of whether the national VAT Code has given further interpretation to the concept of renovation.
Source Deloitte
See also C-239/22 (Belgian State and Promo 54) – Judgment – Condition of the first use of a building