Does supervision require being in same room where personal dignity is at risk? 

I have had several clients who can only shower when someone is in a nearby room ready to come in and assist should they call out or fall, due to their disabilities.
The same issue can arise with using the toilet.
Is there any caselaw to cover this, particularly where the other person is not a partner?

There is not any case law so far as I am aware. The regulations require ‘continuous presence’ but I do not see why that should be further narrowed to ‘continuous presence in the same room’. A person could be continuously present in the next room (or it could be that there is an objective need for continuous presence within the room but that through stoicism and concern for their privacy, that need goes unaddressed).

Certainly in cases dealing with uncontrolled epilepsy and related conditions, I’ve never seen it suggested that someone in the next room over keeping an eye out would be insufficient for 4c.

Will your clients not get their 2 points on 4b in any case given that a risk of falling would tend to support a need for grab rails etc irrespective of whether there is also a need for supervision?

How frequent, unpredictable or severe do seizures have to be before we go past supervision into assistance?

Unless the supervision is primarily to detect the onset of a seizure and warn the claimant, even if there is sufficient warning before a seizure the resulting action is either that the claimant uses grabrails to safely lower themselves, and satisfy (b), or if they can’t: to require Assistance to exit the shower/bath, for (e)?

Taking it further, if the seizure is violent or the person obese, or some other hindrance to the assistant - could you argue that they can’t wash at all, and satisfy (g)?

I think that the problem on ‘assistance’ is that in the circumstances described, there would need to be actual physical ‘assistance’ occurring at least 50% of the time in order to get points, as opposed to simply having someone on standby ‘supervising’ and prepared to act in the event it is required (and perhaps it may never be). Certainly there may be scope to argue for the highest descriptor awards in cases where an activity cannot be safely completed despite aids/appliances, supervision, prompting or assistance.

Returning to the original question. I had said that I was unaware of any case law on this, but in fact you could do worse than KT & SH v SSWP (PIP) [2020] UKUT 252 (AAC). This is the case about taking out hearing aids to go in the bath/shower. In that case, the claimants were supervised by someone who was not in the room and where the bathroom door was closed and locked and the UT held that they got their points (see in particular para 155-157 of that mammoth decision).

Not sure if it adds anything, but LB –v- SSWP (PIP) [2017] UKUT 436 (AAC) also deals with an obstacle to direct (visual) supervision (in this case supervising multiple people at the same time).
The weakness, if any, in KT & SH, is that the supervisor is alert to an external signal(the alarm), so there is no need as such to see/hear the claimant.

Thanks for all the helpful suggestions which I have followed up on.
I was thinking of 2 cases I have had where someone collapses or falls without sufficient warning to grab a rail and it is the sound of falling that alerts the other person.  e.g. POTS, vertigo