15 If the one who dedicates their house wishes to redeem it, they must add a fifth to its value, and the house will again become theirs.

Read Leviticus 27:15 Using Other Translations

And if he that sanctified it will redeem his house, then he shall add the fifth part of the money of thy estimation unto it, and it shall be his.
And if the donor wishes to redeem his house, he shall add a fifth to the valuation price, and it shall be his.
If the person who dedicated the house wants to buy it back, he must pay the value set by the priest, plus 20 percent. Then the house will again be his.