The allocation of additional requirements for heating to households on supplementary benefit (SB) has been challenged recently. Some households receiving an addition spend less on fuel than others which do not. The fuel expenditure of any household on SB is likely to be constrained by income and may reflect ability to pay rather than need. A group of households with zero or close to zero income elasticity for fuel expenditure is identified. The expenditure on fuel of these households can be considered not to be constrained by income and to reflect the real costs of maintaining a warm home in given circumstances. Their expenditure is then used to indicate how fuel allowances might be better targeted.