  We propose and analyze a generalized finite element method designed for
linear quasistatic thermoelastic systems with spatial multiscale coefficients.
The method is based on the local orthogonal decomposition technique introduced
by M{\aa}lqvist and Peterseim (Math. Comp., 83(290): 2583--2603, 2014). We
prove convergence of optimal order, independent of the derivatives of the
coefficients, in the spatial $H^1$-norm. The theoretical results are confirmed
by numerical examples.
