I've just occupied a new building and I have a query about office doors. Most of our doors are solid fire doors but is there a requirement for offices to have a glass strip to assist with office clearances during fire warden checks of the building after an alarm?

Put simply, no.

If the doors have a requirement to be fire doors other than the robustness of the door, then yes.  However, glazing would have to be safety glass so it may be cost effective to buy standard fire panels so they can be replaced if there is a mishap and you need to replace one

Fire doors don't all require vision panels, that's wrong - the regulations state Vision panels are needed where doors on escape routes sub-divide corridors, or where any doors are hung to swing both ways. Note also the provision in Approved Document M Access to and Use of buildings, concerning vision panels in doors across accessible corridors.

I think that the first question that needs to be asked is Are all of these doors required to be fire resisting door-sets? and this then leads on to the question What does your Fire Risk Assessment state? and the last question Are the fire resisting door-sets required for life or property protection?

The provision of Fire Resisting Glazing in fire resisting door-sets could then be for 2 main reasons and these are to provide additional light and safety for persons and for vision into rooms that may be unoccupied but may be a fire risk with no automatic fire detection.

So, before deciding if fire resisting glazing is required you need first to establish if it is required and secondly, why because there may also be a security issue.