Video surveillance of one's own property during house construction

I would like to monitor my property with a camera during the construction (we are building with a large turnkey general contractor). Now the question is: Does the general contractor have to agree? In the construction service description, it was contractually agreed with the general contractor: "For the execution of the construction project, the contractor is granted the house right. This under the condition that the client or third parties authorized by him - for the purpose of safeguarding the legitimate interests of the client - may inspect the construction project at any time and may enter the property for this purpose. Authorized third parties must prove their authorization by a written power of attorney from the client. The builder or third parties commissioned by him must register in due time with the construction manager or the person responsible for the construction site before entering the construction site due to the dangers associated with entering the construction site. Ownership of the construction project passes to the client on the day of handover." I understand the word "house right" to mean that I am still allowed to do whatever I want on my property, for example, to hang up a camera. Would filming my property by a camera of my neighbor be the better solution? I also wonder whether the general contractor can fundamentally stop or refuse work if someone is filming...

I understand the word "house rights" to mean that I am still allowed to do whatever I want on my property, for example, hang up a camera.

For the execution of the construction project, the house rights are transferred to the contractor (AN).

I read from this that you no longer have any house rights. You are only allowed...

the client or third parties authorized by him - to protect the legitimate interests of the client - may inspect the construction project at any time

In this respect, I do not see that you are allowed to hang up a camera. Aside from that, you will probably also have a data protection problem, right? GDPR does not play around.

"For the execution of the construction project, the contractor (AN) is granted house authority. This under the condition that the client or third parties authorized by him - to safeguard the legitimate interests of the client - may inspect the construction project at any time and enter the property for this purpose. Authorized third parties must prove their authorization by a written power of attorney from the client. The builder or third parties commissioned by him must register in due time with the site manager or the person responsible for the construction site due to the dangers associated with entering the construction site before entering the site. Possession of the construction project passes to the client on the day of handover."

I would attach an additional agreement: "The house authority of the contractor regulated in point x.y.z. as well as the prior registration of the client are understood as not exclusive. In particular, outside working hours, the client or a third party authorized by him may enter the construction site at any time and must observe the accident prevention regulations."

I would like to monitor my property with a camera during the construction (we are building with a major solid house general contractor).

That seems excessive to me. You can document so much during weekends and breaks that you won't miss anything essential. The image rights to the foundation earth electrode lie with you, those of the electrician with him. In the last sentence of the quoted passage from the construction performance description, I see the risk of stolen bricks lying with the contractor. Relax. You won't become the richest YouTuber by livestreaming how one of the construction workers spits into the soup bowl *LOL*

I would attach an additional agreement

The contract is already signed :) Regarding the topic "house rules": I understand this as access to the house and not to the property in general. The general contractor (GU) does not work on the property (earthworks and outdoor facilities are the responsibility of the client). If the camera is on the property, the GU theoretically cannot do anything. The construction service description does not mention the property; it concerns the "construction project." It says "register in a timely manner with the construction manager or the person responsible for the site before entering the construction site." Who defines timely? A WhatsApp message 15 minutes before should be enough. Or if I simply say, "I come to the construction site every day from 4 to 6 pm." GDPR (DSGVO) is relevant if all people are directly pixelated / removed and if that is irreversible. There are providers who install such a camera system for you. And if you put up a sign on the construction site explaining who is monitoring and why. There are always cameras on construction sites for theft protection. Nothing unusual.

Livestream

That would really be exaggerated. For example, you could have a photo taken every minute. That would require less storage space... I find the option of the neighbor’s "hidden camera" interesting. Of course, in case of doubt, you wouldn’t have known that the neighbor was running a webcam... Such a "hidden camera" probably doesn’t help you much in court in extreme cases anyway, I assume?

What do you actually want to achieve: turn your construction site into the center of the [SOKO Baumaterialklau], catch construction workers red-handed while botching, present the entire construction fast-forwarded in a few years to the guests of your silver wedding anniversary, ... ?

Grey area. You may install video surveillance if you have a legitimate interest that is demonstrably higher than the personal rights. However, workers must not be identifiable. As a rule, either the excerpts and the recording quality are chosen so that people are not recognizable and/or the surveillance only takes place after working hours. And third parties must not view the material. If you want to do it legally, it is associated with effort.