A warranty is the contractual promise that certain things will be done or achieved, expressed in such certain and definite terms, that the client is entitled to take action for the failure to deliver on the terms of the promise. Therefore it is quite different to the architect's ordinary duty to exercise reasonable care and skill according to the standard of a reasonably competent architect (the professional standard of care), because this does not guarantee, or warrant, a particular result.
Some client-generated client and architect agreements contain clauses with warranties. An example is as below: