This paper presents the assessment of coconut fibre thermal characteristics and its use to modulate temperatures in concrete slabs in the construction industry. Fibre is abundantly available in tropical regions, extracted from the husk of coconut fruits and manufactured at 115.54 MPa to obtain specimens. A first thermal conductivity of k=0.048 (W/m K) is obtained by solving the heat diffusion equation with experimental temperatures as boundary conditions. A second value k=0.0499 (W/m K) is obtained by solving the Fourier's law by using a known heat flux and temperature histories in the specimen. The maximum error between the first and second k values was 3.8%. However, the k=0.048 (W/m K) was used for numerical analysis. Experimental work was done to find density and heat capacity, 174 kg/m(3) and 2600 J/kg K. respectively. Further numerical work was carried out to modulate temperature in concrete slabs. This showed that fibre put on the concrete external surface allows room temperatures to fall within the comfort range. Density, thermal conductivity and heat capacity of coconut fibre were varied in a wide range to investigate the sensitivity of temperature to such changes. This showed that temperature can be considered sensible only to thermal conductivity variations. (C) 2011 Elsevier B.V. All rights reserved.