http://www.legislation.gov.uk/asc/2026/5/section/9Building Safety (Wales) Act 2026enStatute Law Database2026-06-22Expert Participation2026-04-28 PART 1CHAPTER 2 9 1 This section sets out the meaning of “principal accountable person” for a regulated building for the purposes of this Act. 2 The “principal accountable person” for a building with one accountable person is that accountable person. 3 The “principal accountable person” for a building with more than one accountable person is the accountable person who— a holds a legal estate in possession in the external structure of the building, or b is within section 8(2)(b) because of a relevant repairing obligation in relation to the external structure of the building. 4 In subsection (3) (and section 10(1)(b)), “the external structure” of a building means its foundations, external walls and roof except— a any part of the foundations, external walls or roof included in a demise of a residential unit (including a part of the building that would be a residential unit but for regulations made under section 5(6)(a)); b the foundations, external walls or roof of any part of the building to be occupied for the purposes of a business or undertaking (whether for profit or not). 5 Subsection (3) is subject to sections 10 and 11 (determination by building safety authority or residential property tribunal). S. 9 in force at 28.4.2026, see s. 138(1)(a)