•We presents a Hermite interpolation scheme for G2 boundary data and arc length constraint using Pythagorean hodograph (PH) curves of degree 7.•The interpolation scheme is completely local. Each spline segment is defined as a PH biarc curve of degree 7.•In this way the solution of the G2 continuity equations can be derived in a closed form, depending on four free parameters.•By fixing two of them to zero, it is proven that the length constraint can be satisfied for any data and any chosen ratio between the two boundary tangents. In this paper we address the problem of constructing G2 planar Pythagorean–hodograph (PH) spline curves, that interpolate points, tangent directions and curvatures, and have prescribed arc-length. The interpolation scheme is completely local. Each spline segment is defined as a PH biarc curve of degree 7, which results in having a closed form solution of the G2 interpolation equations depending on four free parameters. By fixing two of them to zero, it is proven that the length constraint can be satisfied for any data and any chosen ratio between the two boundary tangents. Length interpolation equation reduces to one algebraic equation with four solutions in general. To select the best one, the value of the bending energy is observed. Several numerical examples are provided to illustrate the obtained theoretical results and to numerically confirm that the approximation order is 5.