Letter: It is surely a vain hope that fair comparisons can ever be made between differing materials in terms of their 'green credentials' (in reference to NSS May issue, page 5, 'Federation seeks to establish its own green credentials for stone').

Here in Purbeck, quarry operators are required to put usable stone back in the ground. Are all industries producing building materials equally effected by such micro management imposed from on high?

Your report says "a lot of water is used" (in masonry production). By recycling what falls on our workshop roofs we draw hardly any from the mains supply.

Given that it is virtually impossible to calculate even such things as what percentage of the cost of a loaf of bread is tax, I suspect that the BRE are attempting a hopeless task in their Green Guide.

Treleven Haysom, W J Haysom & Son and Lander's Quarries, Swanage, Dorset