" If however the services are common to the whole building an EPC for the whole will be required whether you are selling or letting the whole or a part thereof. "
http://www.chpk.co.uk/epcdec.html
"If part of a floor is offered for let and an EPC is prepared for that space, it will be based on the services applicable to that space (ie either common to the whole building where there is a common heating system, or those services serving the part in which the space to
be let is situated) and will need to take account of the energy use of any common spaces."
http://www.communities.gov.uk/documents/planningandbuilding/...
"The lease does mention that conduits for drainage water, waste matter, fresh water and all other things whose use is common to the whole building as being the joint responsibility of all leaseholders."
http://www.landlordzone.co.uk/forums/archive/index.php/t-332...
"Constructions and facades are common to the whole building which allowed these data to be entered at the building level and hence be inherited down to the surface level in each zone."
http://www.designbuilder.co.uk/documents/case studies/david_...