Is Zakat obligatory on an amount of sixty thousand Egyptian pounds collected with the intention of building a house, knowing that paying Zakat will prevent the completion of the necessary amount for construction?

Zakat is obligatory on money saved for purchasing a house if a full year has passed over it, even if the annual saving amount is equivalent to the zakat, because what is obligatory is to give out only a quarter of a tenth, not everything that exceeds the minimum threshold (nisab).