All perfect praise be to Allah, The Lord of The Worlds; and may His blessings and peace be upon our Prophet Mohammad and upon all His family and companions.
In principle, a mere promise isn`t binding; however, if it was attached to a certain obligation or reason, then it becomes binding. Resolution No.(5/2,5/3) of the International Islamic Fiqh Academy(IIFA) reads as follows: "
In Sharia terms, a promise is binding, save if there is a sound excuse. In terms of law, it is binding if it is attached to a reason and the promised has suffered a loss. As a result, the promisor is obliged to either compensate the promised with the same amount that the latter has lost or to fulfill his promise. The Prophet(PBUH) said in this regard, "There should be neither harming nor reciprocating harm."{Ibn Majah}.
In conclusion, the above mentioned carpenter is obliged to compensate you(Questioner) for your actual loss. And Allah knows best.