TECHNICAL INSIGHTS

Difficult Building Classifications

Howard Moutrie - ACAA Accredited Access Consultant Accessible Building Solutions

The articles featured in Technical Insights are to prompt thought and discussion to assist our members' questions and evaluate their understanding of the technical requirements of Australian Standards and other national/international source material. Technical Insights is intended to provide background information, a different viewpoint, a perspective from an individual with lived experience of disability or to prompt further discussion and/or research by you as an access professional.

In this column I will explore some difficult building classifications under the NCC and provide my thoughts. My thoughts may not be correct in all instances but are worthy of consideration.

The NCC assigns groups of buildings with a classification of building type which is used to determine a wide range of requirements. A single building can have a number of parts of differing classifications though we are advised that in a storey, if the use occupies less than 10% of the floor of that storey then it takes the classification of the principal use. Thus, the term building is deemed to mean a building or part of a building. Further, the term building may refer to a structure, such as a swimming pool. The ABCB has produced a series of documents “Understanding the NCC” which includes a document on Building Classifications. This provides some advice on classifying building types.

We shall look at a few classifications and how the accessibility requirements apply.

Swimming Pools

A swimming pool is given the classification of 10b. Table D3.1 of NCC 2019 or Clause D4D2 of NCC 2022 provides requirements for a swimming pool when it is associated with another class of building. Except for a private pool in a Class1a building or associated with a single SOU in a Class 2 or 3 building access into the pool is determined by its size. Notwithstanding this, in a Class 2 or 3 building access I still required to the area surrounding the pool as it is common area for the use of the residents. I do not plan to go into any more detail on this as Paul Eltringham in the Autumn Issue of Insight has already explored the requirements for swimming pools.

I will, however, pose a number of questions. If the pool is in a Class 2 building and the pool occupies less than 10% of the area of that storey, does it take on the Class 2 classification and what would be the implications? I think the difference would only be with respect of access into the pool. I would think that if it were deemed to be Class 2 then as a common area, access would still be required into the pool area only, and access into the pool itself would not be required irrespective of the size of the pool. I have come to this outcome because the requirements for Class 2 building are “ To and within not less than 1 of each type of room or space …… including a … swimming pool…” , that is, it is the area containing the swimming pool which is required to be accessible. I would be thinking that it would be up to the certifier to determine the classification of the pool.

Communal Area On Roof Of A Class 2 Building

Let's assume the roof of a Class 2 building occupies the whole storey and is used as a common recreation area. The normal classification would be part of the Class 2 building and thus access is required to it, but could it be Class 9b, an assembly building? The implications of this are significant – including the provision of toilets.

To be honest, I would not have considered this as a Class 9b, but a certifier on a project of mine recently did – it is an area for social gathering.

A Sole Occupancy Unit

In residential terms, the concept of a Sole Occupancy Unit is relatively clear, or is it? The NCC defines a sole occupancy unit as “a room or other part of a building for occupation by one or joint owner, lessee, tenant or other occupier to the exclusion of any other owner, lessee or tenant”.

In a Class 2 building, this generally applies to the individual units or apartments and the NCC requires access to the front door of each SOU when accessed via common property. This is quite straight forward, but the situation becomes a little unclear when the units are townhouses or townhouse style apartments where access is through a private courtyard. Is the entry to the SOU, the gate to the courtyard, or the entry to the dwelling?

My thought is that the courtyard is for the sole use of the occupant and thus the gate is the entry to the SOU. This is important, because if the gate is the entry to the SOU the path from the gate to the entry to the dwelling could contain steps as an accessible path is no longer required. However, if the gate is not the entry to the SOU and it is the dwelling entry then steps would not be permitted within the courtyard. To me it is clear, the courtyard gate forms the entry to the SOU, but it could perhaps also be argued that the courtyard is not “part of the building” but I would disagree with that interpretation. However, if that argument was true, then access to the entry door of the dwelling would still not be required because the door is not accessed via common property – the courtyard being part of the dwelling.

With the introduction of the Livable Housing Design within the NCC 2022, the situation changes – except for those States who have not adopted this part. This Part of the NCC does not use the term SOU, just dwelling, and unlike SOU the term dwelling is not defined. Under Part 1 of the Livable Housing Design, a step free path is required to the entry of each dwelling, however, for Class 2 buildings Part 1 does not apply on the assumption that access is already required under Clause D4D2(4). Interestingly, if the townhouse was a Class 1a building, which it would traditionally be, then an accessible path through the courtyard would be required, unless the accessible path was provided via the parking space/garage. It is noted there are also other concessions based on the site gradient etc.

In a Class 3 hotel etc, the situation is quite straight forward, each hotel unit is a sole occupancy unit. Access is required to the front door of all units on an accessible floor and into any accessible units.

What about a Class 3 boarding house? Most of this type of building are just the same as an hotel, however, some are designed around a coliving model, where a group of residents, with their own bedroom, share a living area, kitchen etc. Many student housing buildings operate in this way. Refer to the sample plan (right).

It could be considered that each “house” is a sole occupancy unit, like a unit in a residential flat building, but that is not the case. Although the residents may share a living area, bathroom etc, the individual bedrooms are all an SOU. Thus, access must be provided to each bedroom.

To complete this analysis, the definition of a sole occupancy unit includes, for example, an office tenancy though there are no consequences relating to access to the entry. However, it does highlight, what to me is an error in AS 1428.1-2009. You will find that Clause 15.3.2 refers to basins and Clause 14.2 refers to switches and GPOs in accessible sole occupancy units. Technically, a commercial tenancy is required to be accessible and, thus, it could be deemed that the basins, switches and GPOs are required to comply, but it is my understanding that the Standard is referring to residential SOUs in a Class 3 building only.

Administrative Areas In A Building Of Another Classification

A residential aged care building is a Class 9C building and the NCC requires access to the areas used in common by the residents and to the SOUs. There is no mention of the administration area. So, based on the 10% rule, if the administration area was less than

10% of the area of a storey then it would take the 9C classification and access would not be required. However, if it was for example in the basement where it occupied 20% of the floor area, would it then be Class 5? That seems to be a common interpretation, but I am not convinced it is correct. The function of a Class 9C building doesn’t just involve the resident areas the administrative function is an integral part of the building use, so to me it should retain the 9C classification.

A similar example exists in a childcare centre. If the office area is on a separate floor to the “classrooms” does it become Class 5 or is it an integral part of the 9b classification.

The ABCB document I referred to earlier, uses a similar example. They refer to a Class 7b warehouse with an office area occupying 12% of the floor and this is deemed to be Class 5. They actually say “must be classified separately”. To me, and I accept I may be incorrect, but if the office is part of the operation of the warehouse it should take on that classification, however, if the office is separately dealing with the public then I accept that it should be Class 5. I came to this opinion because a Class 5 building is an “office building used for professional and commercial purposes” which to me indicates it is a business in itself not an administrative function of another business.