Heading off from Paddington to Dartmouth, it’s hard not to wonder whether a day trip to Devon’s far west is worth it just to look at a wooden supermarket.

The store in question is Sainsbury’s and, last Monday, the retailer opened its Dartmouth branch without a great deal of fuss. Perhaps it should have made more noise, as what was unveiled to the fortunate inhabitants of this well-heeled part of the West Country was the retailer’s latest stab at an eco-store.

It’s been here before. Back in 2000, the Greenwich peninsula was the recipient of the Millennium store: resplendent with grass roof, wood cladding and jaunty-looking windmills generating electricity on days when a breeze swept along the Thames.

However, things have moved on and the Greenwich store was given a revamp last winter to bring it up to speed with some of the technological developments that have taken place since the start of the decade. The problem that now faces Sainsbury’s, as much as any other retailer looking at how it can reduce its carbon footprint, is that it is not just technology that has moved on, but also mindsets.

More efficient energy-saving measures and new methods of producing power with minimal environmental impact have certainly emerged since 2000. But along with this has come the inevitable accusation of greenwash – the notion that what is being done is more of a marketing exercise than any real attempt to make things better.

This sense is reinforced by comments made by certain retailers in unguarded moments when they ’fess up to doing things because they look good. An example is the development boss of a large supermarket chain admitting recently that the wood cladding on a forthcoming store in England’s Northwest was there for no better reason than that it “looked pretty”.

Which brings us back to Sainsbury’s in Dartmouth. This is a timber-framed structure and, like the one that Tesco built in Wick, it costs more to build than a store of the same size using conventional methods. It does, however, emit 40 per cent less CO2 than a standard outlet of this size and, allowing for continuing energy price rises, it also has the scope for a measure of pay-back in terms of building costs.

It’s a pity that there is so much greenwash about, because its net effect is to undermine the good work being done in places like Dartmouth. Retailers are getting on with the business of selling merchandise, but the best ones really are cleaning up their act, in spite of the cynicism and uncertainty regarding such efforts.