Addendum to the construction time extension due to access/driveway

Hello,

I have a question regarding the extension of the construction period for consumer construction contracts. Our contractor has submitted a change request with a construction period extension of 2 months, arguing that our access road to the property is too small.
A construction crane and a 4-axle truck can probably get through without any problems, but an articulated truck or a semi-trailer truck cannot make the turn.
The property was known at the time of contract conclusion and could have been checked by him.
We are building a city villa, monolithic with 2 full floors.

Does the contractor have a legitimate interest in claiming the extension of the construction period?
How should we deal with the change request?

Who bears the additional costs if deliveries have to be transferred to smaller vehicles?

Best regards and thanks for your tips.

What does the contract say about access? For me, it was very clear that it is the builder's obligation to ensure that vehicles xy can enter the property.

It only states that access must be secured for vehicles with a total weight of up to 40t.

A lawyer will probably have to advise you on that. As a layperson, one might guess that this wording implies that an ordinary 40-ton truck including concrete mixer semi-trailers, etc. must be able to drive in. But I guess the question is how a judge would see it... Back then, every construction company asked me if there could be problems with access. Has yours never asked that?

Everything related to the property (including construction access road) is the responsibility of the builder. So yours. The contract partner or general contractor builds the house. Everything else can be carried out by the contract partner at an additional cost. Since you are asking here, you will not avoid a lawyer to gain the security that is important to you. Or search the fine print afterwards. If the contract partner is in the right, then the follow-up costs etc. are your problem. But since you usually do not terminate your lease before installing the floor covering, the costs should remain manageable.