Commercial EPC exemptions?

Property split into 2 commercial lets.
Lessee No 1 Retail shop ground floor (EPC C).
Lessee 2, D2 category 2 x floors above (EPC E).

Solid wall building, terraced, on a high street in a conservation area.

Neither I or lessee will want to be paying out to get to an C if this is also part of Red Ed’s net zero which hunt. Any costs I would be forced to make would just add to the rental charge (lessee struggling as it is). Contract remains silent about which party liable for EPC upgrades.

Is it possible to register an exemption?

PRS Exemption Registration Requirements states the CURRENT regulations (as of 1 April 2023 must be E or above) but exemption possible if landlords are able to demonstrate a number of things.

One of the points is: Consent Challenges: If further consent is required, either from the local planning authority or a third party and has been refused for energy improvements.

What does a third party refusal mean in this sense – from the tenant themselves, from one of the Freeholders (if the Freehold is split ownership)?

Does anyone already have a commercial EPC exemption?

I appreciate noting set in stone yet but if exemptions currently apply I’m assuming that this would be the case.

Thanks,

Reluctant landlord