Is it permissible to increase the amount agreed upon for a house design due to price increases two years after the agreement?

It is not permissible to increase the amount owed by the debtor due to rising prices, because debts fixed in a specific currency are repaid in kind, not by value. A resolution was issued by the Fiqh Academy affirming that the consideration for fulfilling fixed debts is by kind, not by value, and it is not permissible to link debts to the price level.