What is the ruling on agreeing to take a specific amount as profit if the partner is late in building the house agreed upon within the specified period, given that I am a merchant and invest money?

We understand from the question that the questioner will contribute money and his partner will build the house. The questioner stipulated the return of his money and a known profit if the house is not built within a year. This condition is not permissible because it contradicts the essence of partnership and includes a guarantee of capital and a known profit, and making one partner's share a known amount of money invalidates the partnership.