A more thorough explanation:

Definition: Spondet peritiam artis is a Latin phrase that means "he guarantees his professional skill." It is used in construction contracts to show that the person promises to use their skills to do a good job.

• When a contractor signs a contract to build a house, they are making a spondet peritiam artis promise to use their skills to build the house well.
• A plumber who promises to fix a leaky faucet is making a spondet peritiam artis promise to use their plumbing skills to fix the faucet correctly.

These examples show how spondet peritiam artis is used in contracts to indicate that the person promises to use their professional skills to do a good job.