Tenant Sub-metering Question

As described in various responses below, the general answer is that the CS building metering network must have the capability of accomodating the implementation of ID&C EAc3. This does not mean installing the meters themselves, but rather installing a data system capable of receiving, transmitting, and collating meter data from the tenant spaces. For some tenants this could be as simple as a single electrical meter. For others it could mean multiple meters for individual end-uses. It depends on whether the tenant is Case 1 or Case 2 under EAc3. In this regard, see my response to Mike Lui below for elaboration. More to your specific question, the CS system generally must be capable of managing decent volumes of data (e.g. hourly), since this is what will be required for most tenant spaces to meet the requirements of EAc3. To be blunt, I have difficulty imagining a tenant space where a simple "accumulating" meter and monthly reporting would be sufficient to meet the intent of EAc3. The physical format of the data network is up to your discretion - it could be any number of configurations including hard-wired, web/IP-based, etc. Having said all of this, consider what is appropriate and do what is sensible for your project. Far too many metering systems that I encounter are seriously over-designed and/or over-capable.