Abstract: Batter board apparatus for use in building construction, including first and second sleeve members hingedly connected and adapted to slidingly receive first ends of first and second elongated board members, respectively, for hinged movement between parallel positions adjacent each other and positions mutually perpendicular to each other. The first and second sleeve members are provided with a common tubular member the axis of which is perpendicular to their hinged movements. Third and fourth sleeve members, adapted to receive second ends of the first and second elongated boards, respectively are also provided. Each of the third and fourth sleeve members are provided with a tubular member the axis of which would be perpendicular to the elongated board members when engaged thereby.