EWNs on facility for supply of goods - what is the client´s limit?

[Inkdeck]

We have a NEC3 contract with a client for manufacture and supply of Goods. Within the contract, the manufacturing facility is defined and has a mention that the facility shall be used to manufacture the Goods. The facility is an existing one and we have leased it from a landlord. The sheds are very old (45+ years) and the client had visited the facility prior to awarding the contract. Now, we are receiving EWNs one after the other on the grounds that the sheds are not compliant to the latest EU / EN / BS codes of structures. The client demands compliance to numerous standards even in the small repairs and civil works that are done to the facility. All EWNs are issued with possible consequences of delayed delivery, affecting the work of the purchaser and increase in total price. We are of the opinion that we signed up for the supply of goods. We are certified to the applicable standards for HSE and QSM under the ISO systems. If any, the client should be entitled to issue EWNs only if the perceived incompliances should have any direct effect on the Goods to be supplied. What is the entitlement of the client to certify and interfere in the preparation of the facility, which is the supplier´s asset? The client takes a simplistic view that since the facility is a defined term in the contract, it is a deliverable. The number of EWNs and the long drafts in each reflect a deliberate attempt at being pompous, with a threat of breach of contract. We would rather focus on getting things done than to engage in a battle of letters. Is it mandatory to respond to an EWN and in case a response is not given, is it a breach?