A novel form-stable phase change material (FSPCM) was prepared, which comprises micro-encapsulated paraffin (MEP) as the latent heat storage medium and high density polyethylene/wood flour composite as the matrix. It has the following merits: proper phase transition temperature, large apparent specific heat in phase change temperature region, suitable thermal conductivity, good shape retention and dimensional stability. Therefore, it is suitable for the applications in energy efficient buildings without encapsulation. Simulation studies were performed to investigate the temperature-regulating and cost-reduction effects of the FSPCM as the thermal storage layer (TSL) material of an electric floor heating system (EFHS). The results show that it is promising to use the FSPCM plate as the TSL to achieve better temperature-regulating and cost-reduction effects, and the application effects depend on the heating mode of the EFHS and the thickness of FSPCM plates. The cost-benefit analysis indicates also that the prepared FSPCM has the potential to serve as the TSL in an electric floor heating system. (C) 2009 Elsevier B.V. All rights reserved.