I have seen that while I was on holiday, Huntingdonshire DC published their preliminary charging schedule. Although the number of published charging schedules is growing (but small), I have yet to see 2 alike in terms of the approach taken on differential rates according to intended use (as opposed to the approach to differentials according to "zones" which, as you'd expect, is more consistent) with residential development carrying the majority of the burden so far. It is also fair to point out that the use classes contained in the Use Classes Order are usually relied on to describe intended uses for the purposes of any differential rates allowed in relation to use.
The HDC draft seemed to me the most "creative" yet. The standard rate of £100 (per sq m) applies to all development unless otherwise set out in the schedule. Then we see individual rates for large retail (A1/A2/A3/A4/A5) (1,000 sq m or above), small retail (same use classes), Hotel (C1), Nursing Home (C2), health (D1), Business (B1), General Industrial, Storage and Distribution (B2 and B8) and Community Uses (within D1 and D2). Those individual rates range from £45 (nursing homes) to £140 (large retail and health) - with B1/B2/B8 having a nil rate.
I can see that the viability evidence may point to quite subtle differences as between different uses even within use classes (and after all, differential rates can only be justified on viability grounds), but there is a risk in seeking to be quite specific. For instance, care must be taken to be clear what "retail" means if non A1 use classes are to be referred to. What are "community uses" in D1 and D2? And if a D1 development can be constructed for a "health" use without CIL - does that leave the door open for a subsequent change (within D1) to a non health use e.g. education without a CIL payment?
As more schedules come forward in the next couple of years, with Councils seeking to bring in CIL before April 2014, it will be interesting to see how these issues pan out.