Before calling an object an heirloom, ask who made it, whether it can be repaired, how the material will age and whether the design will remain useful after fashion moves on.
Look for evidence of the hand
Good craft is not a performance of imperfection. It is the visible result of decisions, with joins that can be understood, materials used honestly and finishes chosen for the life the object will lead.
Repair is part of beauty
An object intended to remain should allow care. Replaceable parts, accessible makers and forgiving materials are often more luxurious than immaculate surfaces that cannot be restored.