In October 2024, the First-Tier Tribunal (Property) (FTT) published a case decision which caused confusion as to what constitutes a ‘higher-risk building’ under the Building Safety Act 2022 (the BSA). The case involved a successful application by leaseholders of a mixed-use building for a remediation order relating to fire-safety matters at the building. The grant of the remediation order was not the issue but, rather, it was the scope of the order and the FTT’s comments in handing down its decision, which included an opinion that a roof top garden counted as a “storey” for the purposes of defining the parameters of a “higher risk building” (HRB) under the BSA. 

This provoked interest and concern amongst the building sector, as the FTT appeared to contradict the Government’s published guidance for determining whether a building should be treated as ‘higher-risk’. This was particularly concerning as HRBs are subject to an enhanced regime requiring registration with the Building Safety Regulator (BSR) and an increased role for those ‘accountable’ for the building. The recipient of the remediation order submitted an appeal and the Upper Tribunal (Land Chamber) (UT) published its decision on 4 June 2025.

Background

The BSA, which was enacted following the Grenfell Tower fire in 2017, contains provisions intended to ensure the safety of people in, and standards of, buildings, particularly tall buildings. Broadly speaking, Section 120D of the Building Act 1984 and Section 65 of the BSA define HRBs as those buildings which (1) are at least 18 metres tall or at least seven storeys in height; and (2) are of a specified description, including that they contain at least two residential units. Section 65 of the BSA is subject to the Higher-Risk Buildings (Descriptions and Supplementary Provisions) Regulations 2023 (the Regulations) which contains information as to how to measure the height of a building and to count storeys.

The Regulations state: 

"when determining the number of storeys a building has the following is to be ignored…(b) any storey which is a roof-top machinery or roof-top plant area or consists exclusively of roof-top machinery or roof-top plant rooms” but they make no specific reference to roof-top gardens or terraces. 

In 2023 the Government published guidance stating that:

“A storey must be fully enclosed to be considered a storey. The roof of a building should not be counted as a storey. Open rooftops such as rooftop gardens are not considered storeys”. 

The case of Blomfield and Others v Monier Road Limited (Smoke House & Curing House) LON/00BG/HYI/2023/0024 concerned two wings of a single mixed use residential/commercial building, purpose built between 2016 and 2018. The roof of the building housed plant and machinery, as well as a roof garden. The case was brought to the FTT by the long leaseholders of the 29 residential units against the freeholder, Monier Road Limited (MRL), to compel MRL to undertake, without delay, replacement of certain high-risk cladding materials used in the construction of the building. 

The FTT’s decision, handed down in July 2024, included a lengthy discussion as to whether the building was an HRB, with the FFT considering the meaning of the word “storey” and casting doubt on the status and accuracy of the Government’s guidance documents. In reaching its decision, the FTT classed the building in question as higher-risk on the basis that, in calculating whether the minimum seven-storey threshold for HRBs had been attained, the top storey comprising of a roof garden and plant should be counted. The result was the issuing of a remediation order which contained ‘additional’ items appropriate for an HRB. 

Updated guidance

In May 2025, MRL appealed the remediation order on the basis that the scope of the order was too wide and included ‘additional’ items that were not before the FTT for consideration. The UT was asked to re-make the remediation order to remove, amongst other things, the requirement for MRL to submit the order to the BSR, as that order arose solely from the FTT’s opinion that the building in question was an HRB.

On 28 May 2025, before the UT’s decision was handed down, the Ministry of Housing, Communities and Local Government (MHCLG) published updated guidance confirming the Government’s earlier position that roof gardens are not storeys for the purposes of determining whether a building is a ‘higher-risk building’ under Section 120D of the Building Act 1984 and Section 65 of the BSA. The MHCLG confirmed that, in reaching this position, it considered the FTT’s decision from July 2024. It noted that, given the need to provide clarity within the legislation, it is consulting with the BSR and other relevant stakeholders regarding proposed amendments to the Regulations. 

The following week, the UT found in favour of MRL and set aside the FTT’s decision to require remediation of the ‘additional’ items. The UT confirmed that the BSA does not give the FTT jurisdiction to decide whether a building is an HRB and, indeed, the FTT had previously noted that its comments on this point were merely an “expression of opinion”. The UT concluded that the FTT's decision included no sound explanation for raising the ‘additional’ items and that it exceeded its discretion in doing so, resulting in a decision which was “procedurally irregular and unfair”. It further commented on the damage and uncertainty caused by the FTT’s lengthy consideration of the application of the definition of HRBs, and the Government’s guidance, both for the leaseholders of the building in question and for players in the building industry more widely.

What does this mean for roof-top gardens?

The decision of the UT, which unlike the decision of the FTT is binding on future cases, suggests that the FTT’s comments regarding the definition of HRBs should not hold weight but the UT itself did not opine on whether roof-top gardens should be considered storeys. At present, the MHCLG advises sector and regulatory bodies to continue to refer to the latest Government guidance; this states that roof-gardens and other non-enclosed rooftops should not be included as a storey for the purposes of determining whether the threshold for HRBs has been met. 

However, whilst the MGCLG consults with relevant stakeholders and considers further legislative updates to the Regulations, there is still some uncertainty for those active in the building sector. Given the wide implications of falling within the HRB categorisation, stakeholders should carefully consider plans for buildings and seek advice on a case-by-case basis, particularly where they are planning to meet environmental targets through the inclusion of a roof-top garden or terrace.