Williams, R G; Ballard, G (2007) Evaluation of the thermal performance of insulation systems used in roof structures. NPL Report. MAT 8
Williams, R G; Ballard, G (2004) An investigation of measurement procedures needed to determine thermal transmittance of deep structures using both horizontal and vertical heat flow. NPL Report. DEPC-TH 002
Williams, R G; Ballard, G (2004) An evaluation of the effect of high performance spacer bars on the thermal performance of a range of window systems. NPL Report. DEPC-TH 001
Williams, R G; Ballard, G (2003) Validation of the NPL rotatable wall guarded hot box with horizontal heat flow. NPL Report. CBTLM 25
Williams, R G; Ballard, G (2003) Calibration of a surround panel used to measure window and door U-values in the rotatable hot box apparatus as specified in BS EN ISO 12567-1:2000. NPL Report. CBTLM 26
Williams, R G; Ballard, G (2002) Calibration of a surround panel used to measure window U-values in a hot box apparatus as specified in BS EN ISO 12567-1:2000. NPL Report. CBTLM 18