Films of titanium oxynitride are assessed for their potential as energy saving coatings on window glass. The coatings are deposited from the atmospheric pressure chemical vapour reaction of TiCl4 and ammonia. Film microstructure and composition was analysed using scanning electron microscopy, X-ray diffraction, pulsed RF GD OES and X-ray photoelectron spectroscopy. Transmission and reflectance spectroscopy were used to investigate the optical properties of the films. In this study optical data is used in building simulations to predict the savings made by these novel thin films compared to standard products, for locations with different climates. The results suggest that such glazing can have a significant energy saving effect compared to current approaches across a wide range of climate types. Crown Copyright (C) 2013 Published by Elsevier B.V. All rights reserved.