ᐅ Architect Improperly Estimates Brick Facade Area

We are not building a house yet but are talking to as many homeowners as possible and reading extensively in this forum to prepare ourselves and at least avoid the biggest mistakes.

Yesterday, we had an interesting discussion with friends who have since abandoned their house construction because they became frustrated. I would like your opinion on one point from the discussion:

The architect prepared a tender for the brick facade. He calculated a certain area x and included this in the tender documents. The homeowners awarded the contract to a company. Only afterward did it become clear that the facade area was much smaller than stated in the tender. The facade company now wants to be paid for the difference. Who is liable here? The homeowners awarded the contract and initially face the problem. However, they relied on the architect’s professional expertise. Can they hold the architect liable?

How can such a misunderstanding be avoided? As homeowners, you can’t verify everything, can you?

Thanks in advance for your opinions.