Building Code vs. VOB/B - Security Deposit?

We have a contract offer that clearly refers to VOB/B.

Does the new Construction Law [Baugesetzbuch Baurecht] then not apply – in particular the max. 90% advance invoice issuance and the 5% retention of security?
There is nothing about this in the payment schedule...

Thank you

Hello Donludo,
The Building Code always applies in general. If a contract is agreed upon according to VOB, then VOB always takes precedence (higher overrides lower). Only in cases where VOB does not provide regulations for certain matters does the Building Code apply.
The right to payment and retention is also regulated in the VOB. It may also be the case that the contractor has a performance bond and/or warranty bond, in which case he is entitled to 100% payment.
But I believe you mean something completely different. The mentioned payment plan primarily regulates the due dates of the payments. It is generally individually negotiable but is subject to the provisions of the Real Estate Agent and Developer Ordinance.
Obviously, you want to build with a developer. He certainly has presented a payment plan in 7-9 steps. It usually starts at the beginning of construction and ends with the acceptance, whereby defects and remaining services are to be deducted here.
The payment plan contains percentages of the total construction sum and are due in full (exception last installment). Any additions are usually invoiced after completion. There are dozens of articles on this topic on Dr. Google.

If a contract is agreed upon according to the VOB, the VOB always takes precedence (higher rank overrides lower). Only in cases where the VOB does not provide regulations for matters does the Construction Code apply.

No. The VOB/B itself is not a law but general contractual conditions. It must also be effectively incorporated – especially towards consumers.
A VOB/B contract with consumers has therefore meant since 2018: Construction Code + VOB/B.
This also ensures consumer protection (which was previously guaranteed by the Federal Court of Justice jurisprudence; the ruling at the time: No VOB/B against consumers, but interpretation in the sense of the Construction Code contract law).

If a construction contract within the meaning of § 650 a Construction Code is present, then since 01.01.2018, in addition to the regulations on the contract for work, §§ 650 b – 650 h Construction Code apply additionally.
According to § 650 n Construction Code, deviations to the detriment of consumers from the provisions serving consumer protection of the §§ 650 h – 650 k Construction Code and § 650 n Construction Code are not permitted.

Section 650 m para. 1 Construction Code (= total amount of installment payments may not exceed 90 percent of the agreed total remuneration including supplements) is thus not covered, i.e. negotiable. Other divergent individual arrangements are therefore possible.

It is generally individually negotiable, but subject to the regulations of the Broker and Developer Ordinance.

Broker and Developer Ordinance only applies if it is a developer contract (work + land) – which is not clearly evident here.

Thanks to @Otuss11. I learned something again there. And how does your contribution now help the questioner?

Do I understand correctly that the VOB/B conditions are significantly better from a consumer protection perspective, regarding the security retention? In the VOB/B, the retention may be kept until the end of the warranty period, but in the Baugesetzbuch only until acceptance.