The principle also applies for an architect (planner) contract that agreements must be kept (pacta sunt servanda):
No changes to the contract without the consent of both parties
- Principal and architect (planner) must agree to a subsequent contract modification.
- A signed change and amendment agreement is necessary when the validity is subject to a written form.
Reservations for unilateral contract change
- If and to the extent mandate contract law (OR) is applicable, the client’s (principal’s) revocation right creates the corresponding basis for contract changes, although a reduction in services may not be done in an untimely manner (OR 404).
- SIA standard 118
- Article 84 paragraph 1 foresees a unilateral amendment right (design right) for the scope of services under certain conditions.
- SIA order 102 and SIA order 103
- Both of these do not contain any SIA orders concerning the planner related to performance changes or design law.