The broad motivation of this work is a rigorous understanding of reversible, local Markov dynamics of interfaces, and in particular their speed of convergence to equilibrium, measured via the mixing time T mix . In the (d + 1)-dimensional setting, d ⩾ 2, this is to a large extent mathematically unexplored territory, especially for discrete interfaces. On the other hand, on the basis of a mean-curvature motion heuristics [Hen97, Spo93] and simulations (see [Des02] and the references in [Hen97, Wil04]), one expects convergence to equilibrium to occur on time-scales of order ≈ δ −2 in any dimension, with δ → 0 the lattice mesh.We study the single-flip Glauber dynamics for lozenge tilings of a finite domain of the plane, viewed as (2 + 1)-dimensional surfaces. The stationary measure is the uniform measure on admissible tilings. At equilibrium, by the limit shape theorem [CKP01], the height function concentrates as δ → 0 around a deterministic profile ϕ, the unique minimizer of a surface tension functional. Despite some partial mathematical results [LT15a, LT15b, Wil04], the