Hi,
This situation requires the use of QNE. This is the procedure where by the pilot sets 1013 on the altimeter and the controller gives you descents based upon that. So if you on a vfr approach for example, they will say "your altimeter will read x feet on touchdown."
I've never had to use it myself nor do I believe it's something written down in my own company ops manual but it's something I remember from training. Be interested to hear whether any controllers do this or have other methods in place ?