The statutory code does not of course impose legal obligations. Nor is it an authoritative
statement of the law; only the tribunals and the courts can provide such
authority (taken from the code :-) )

Most employers will rightly seek to ascertain, a working assumption of, if an employee is covered by the provisions of the equality Act or not. Usually by using an independent Occupation Health service

Not being pedantic but in your first sentence "Employers must make reasonable adjustments for workers with disabilities, physical or mental health conditions." I am not sure this is quite right. Employers must make reasonable adjustments where an employees condition is covered by the Equality Act and that is quite well defined.

I think its entirely reasonable to utilise something like an Occ health service to see if , in their opinion, someone is likely to be covered by the equality Act, and if so, what reasonable adjustments they would recommend.

On your point "sometimes these are not manageable or reasonable within our setting." Then teh act allows you to say no and you should as they are not reasonable for you in your context. 

In reply to Keith:

I would maintain that it it is not easy to decide if people are covered by the Equality Act or not It is notoriously difficult albeit Occ health can assist.
I would however maintain that employers should and do try to help people with illness/injury regardless of whether they may get over the 'disabled line'.
The example I usually use was when our colleague broke her ankle. We did not worry about whether she was disabled or not but what we could should do to help her through her period of 'confinement'
I know that this was only temporary and only a minor inconvenience to us but the principle remains sound. My colleagues would work around my colour blindness even though it is not a disability.
i would also add that judges do not seem to like employers being overly fastidious about disputing whether someone is disabled or not. I reserve the right to disagree with them but it is no where I would focus, which always has been on Reasonable adjustments.

In reply to Keith:

Thanks Keith, my first sentence was more to set the subject of the query and I do realise that the requirement is for employees covered by the Equality Act. As you have stated when we use occ health the report provides us with information around recommended adjustments and confirms if the employee is likely to be covered by the Equality Act. What Peter has shared below is what I am struggling with at present, that it is not easy to decide if people are covered. Occ health can be very expensive and is not always a route that we would consider taking in some of the cases we have. It seems that many of our staff are very aware of the duty employers have to make reasonable adjustments and, as often is the case in HR, the circumstances are not always black and white and having the confidence to state that we can't agree to the adjustment is proving difficult in some cases. I also struggle with how we have treated others and being consistent. For example, if somebody needed an adjustment that meant that they could not work with a particular group of classes because they had difficulty walking long distances and we agreed to make this adjustment for this individual, what happens if we can't make that same adjustment for another individual at a later date? We are a large school and we may be able to manage that adjustment for 1 individual because there are other classes that the employee could work with who do not require them to walk long distances but by making that adjustment they would not be performing part of their role. If another 2 or 3 members of staff had similar adjustments needed (on a perm basis), we may not be able to make the adjustment due to that taking it to 3 members of staff who cannot perform part of their role and it being more difficult to manage 3 people who can't work in certain class groups. Could we be in a tricky situation if we state that we can't make adjustments at a later date if further similar cases arise?

In reply to Amanda Cherry:

Do not worry about the future. The circumstances will be different and may mean that a future adjustment is no longer reasonable.

I agree that if you've made a reasonable adjustment for one person, it doesn't mean that you have to offer the same solution to all. By definition, making the adjustment (a bit like flexible working requests) means that you have less capacity to accommodate others. Being consistent in approach is important (dealing with requests fairly and without favouritism), but not being consistent in the outcome.