This paper aims to investigate the typical indoor environment in Tibetan residential dwellings, which has particular architectural form and environmental adaptations. The field measurements during the summer month show that the traditional house presents high humidity, low temperature. And the indoor environment is much worse in winter. Tibetan architectural features and ethnic customs are taken into account in the creation of passive renovations that are applied with minimal effect on the overall architecture. Numerical simulations of the indoor thermal environment are conducted on the building models using DeST-h. Different renewal measures are evaluated in terms of how much they decrease annual energy consumption. Orthogonal experiments are designed to optimize an array of energy-saving building renovations to reduce energy consumption and improve indoor thermal comfort of Tibetan residential houses. Results show that there is an obvious reduction of energy consumption by combining appropriate renovations based on orthogonal optimization. The conclusion is that there are economic and environmental benefits of using natural passive methods without considering mechanical ways. The renovations are verified as effective for reducing energy consumption and improving indoor comfort in such Tibetan residential dwelling. (C) 2015 Elsevier B.V. All rights reserved.