If you build a new house, you are to construct a railing around your roof, so that you do not bring bloodguilt on your house if someone falls from it.
KJV
When thou buildest a new house, then thou shalt make a battlement for thy roof, that thou bring not blood upon thine house, if any man fall from thence.
ASV
When thou buildest a new house, then thou shalt make a battlement for thy roof, that thou bring not blood upon thy house, if any man fall from thence.