In new commercial buildings, some developers are considering ‘superloo’ arrangements as COVID-19 mitigation, or choosing to increase the space allowed for washroom facilities, as illustrated.
Approaching a washroom, one normally encounters a vestibule or lobby with two doors. The role of this lobby is to prevent the transfer of sound into the office space, help reduce air leakage to adjacent spaces and avoid direct sightlines. Thought should be given to the necessity of these doors, and how people enter and exit through them. The aim is to reduce the need to touch the doors or, where this is unavoidable, at least to provide conveniently placed hand sanitiser stations and waste bins (to allow paper towels used to open doors to be deposited). The desire to create a touch-free experience has led to an increase in automated and foot-operated doors, both for the vestibule arrangement and for WC cubicle doors. Research by the US Centers for Disease Control and Prevention (CDC) 5 suggests that toilet plume could play a contributing role in the transmission of infectious diseases, and while additional research is underway, it may be best to close the toilet lid (if provided) before flushing.
There are a number of ‘emerging’ products and methods that are being discussed for beneficial use in washroom areas. These include the installation of ionisation units to purify the air, UV light surface cleaning and antiviral surface coatings. While these may be worth considering, at the time of writing there is not sufficient evidence to fully understand their effectiveness.
Washrooms are integral to the functional use of the office space. The challenges presented by COVID-19 have exposed how the resilience of these key facilities can be compromised.
Changes might be as simple as facilitating social distancing through creating a labyrinth entry to allow the omission of doors, automating doors, spacing hand basins and urinals further apart, or providing full-height WC partitions.
Perhaps the standard washroom layout should be questioned. There has been an increase in interest in ‘superloos’ or unisex washrooms, as these offer individual self-contained toilet and basin facilities, which make social distancing easier to achieve. Each superloo is separately ventilated, thus reducing the mixing of air compared with more traditional washrooms. This layout also provides a flexible gender-neutral provision, which can easily accommodate changes in the proportions of male and female users.
To assess the potential impact on floorplate efficiency, a key metric for office design, the difference in area needed to accommodate a unisex superloo compared with traditional single sex toilets for a notional office space has been investigated. The study was based on a 900 m² NIA floorplate, a 1 person per 10 m² occupancy density and a 60:60 male/female gender split for the traditional single‑sex toilets. Based on the level of provision recommended in BS 6465-1,3 the requirement would be as follows:
- superloos – nine unisex WC cubicles with integral hand basins (this includes the recommended 25% increase in provision to cater for increased dwell time)
- traditional single-sex toilets –three WCs, two urinals and three hand basins for men, and five toilets and five hand basins for women.
Both of these options provided the required facilities to serve the assumed 900 m² NIA floorplate. It was noted that, by using the traditional setting out of the gender-split toilets, it was possible to create a compact arrangement that was approximately 17% smaller than the superloo arrangement with an access corridor. This is illustrated in the sketch layouts shown in Figures 4 and 5. However, when consideration is given to the other recommended measures, such as full-height partitions and separation of basins to ensure social distancing, the gender-split washrooms become larger and occupy a similar area to superloos.
