Ashton Gate Sainsburys and sustainability

Those of you who read this blog regularly will know that I've been being put under a degree of pressure to oppose the plans for a larger Sainsbury's supermarket at Ashton Gate, which is going to the planning committee tomorrow.

Having read through the lengthy documentation, I have now submitted a statement, which is appended at the bottom of this posting for information. I have not commented on the 'need' for a supermarket on the site as I simply don't feel qualified to do so - I don't live in the area or represent it and I frankly don't know it that well. I have focused in, instead, on the sustainability aspect.

This application raises one of those interesting dilemmas that are going to arise more and more as we focus in scientifically on climate change. It concerns how you anticipate car usage for future developments. The documentation covers a difference of opinion between the applicants and the Council as to whether this would be 10% or 20% more than the current store. The truth is (a) nobody knows, and (b) we don't know what these cars would have otherwise be doing. For example, the new store might increase traffic in the immediate vicinity, but it might do so by diverting traffic from elsewhere. It might even reduce car use overall, by providing a retail outlet closer to people - e.g. people go to the new homeware section of Sainsbury's rather than going to IKEA or Cribs Causeway or wherever. But, no-one knows, so it is right that the worst is assumed at this stage.

It is calculations like this that we, as a society, need to get better and better at doing in the coming decade. If we are to reduce carbon emissions at the scale we need to, we need to understand the ramifications of actions and try to avoid the law of unintended consequences. I am, by training and instinct, a scientist and there is limited space in positive environmentalism for gut feelings and guesswork, in my view. We need to be able to measure, understand and act.

The substance of my statement is thus that Sainsbury's need to do better than the pretty good building sustainability standards to offset the worst case carbon scenario from the traffic. What I am proposing is not cheap, but it is well within the purse of a corporation like Sainsbury's and not that significant in the scale of the project as a whole.

I am wishing to make a statement concerning the proposed new Sainsbury’s supermarket at the Ashton Gate site. I am restricting my comments to issues of energy use and carbon emissions. This should not be read to mean that I approve of other features of the application, but that I do not feel qualified to comment on them, not knowing the area well.

I recognise that the sustainability of the construction of the new building is strong, with a projected ‘Very Good’ BREEAM rating, a biomass boiler providing a renewable energy supply for heating and a range of energy saving features. The applicants are to be commended for this.

However, I also note the projected increase in road traffic that is anticipated as a result of the growth of the Sainsbury’s ‘offer’ in the Ashton Gate area. By their nature, such future predictions can be only that, but the estimate of a 20% increase would seem reasonable, as noted in the officer report.

There will be carbon emission implications from this increase in road traffic and this needs to be factored into the overall impact of the development. Whilst the limited attempts to encourage modal shift are recognised, the reality remains that the vast majority of journeys to a large supermarket are made by car to enable the goods to be transported away.

On this basis, and recognising that Sainsbury’s is a very large company who are seeking to reap extensive profits from the site, I believe that the Council’s expectations for energy use and carbon reduction need to be higher than at present. I would therefore urge the Committee to require the following additional features :

1. A requirement that the building should be constructed to a BREEAM rating of ‘Excellent’. It is noted that the applicants are aspiring to this, but there is no requirement currently planned. Requiring this through condition would help to reduce the overall carbon impact further, as well as setting a positive example to other developers in the city.

2. A requirement that the roof should house a significant photovoltaic solar array. Whilst the full design has not yet been submitted, it is highly likely that it will feature large amounts of south-facing flat roofing that would be ideal for solar energy production. This would help to reduce the inward electricity draw for the building and thus also help to reduce the carbon footprint. The Council is planning for such arrays to be mounted on its building stock and the private sector should be following suit.

3. A requirement that a ‘green roof’ should be used outside those areas used for solar panels. This would help to both soften the visual impact of the building and provide a useful bio-habitat in an otherwise urban setting.

4. A requirement, through an S106 agreement, to provide a significant number of additional large trees in the immediate area. The intention to increase planting on the site itself is noted, but this is relatively limited in scale. Given the increased traffic, the provision of additional trees nearby would help to offset the carbon emissions, as well as providing useful shading. This would be in keeping with the policy to increase canopy cover in the city in the Core Strategy.

I strongly believe that if the argument that this application is an ‘enabling development’ for the stadium is to be accepted by the Committee, the Committee has a right to expect that the carbon impact on the city will be minimised. The four measures listed above would take us strongly in that direction.