Why do shops leave their doors open?

Businesses can save energy as well as homes and one easy way for shops to do this, at least you would have thought so, is to close the doors when it's cold outside. We do at home - why don't the High Street shops do the same? There is a campaign to persuade them to do this, called close the door .

When challenged, shops cite all sorts of reasons not to close their doors including:

• It makes it difficult for people with pushchairs or wheelchairs to get inside.
• It discourages people from coming in.

There are many ways to fix the first problem. The Disability Rights Commission does not recommend that doors are fixed open, merely that doors are easy to open and close - having a well designed handle and making sure the door closer isn't too tight is usually sufficient (1). The second issue however is hard to disprove. Close the Doors paid for some research to see what the savings could be and whether closed doors really did lead to fewer customers or not. You can download the full report here.

To put all this into perspective, heating within the retail sector is responsible for about 1.2% of carbon emissions from the UK as a whole (2). This is slightly less than carbon emissions from lighting in that sector - and LED lights could help a lot there (see Should I buy LED light bulbs? in this blog).

The Close the Door researchers installed monitoring into two shops in Cambridge: the Cambridge Toy Shop on Sussex Street and Rymans on Sidney Street. For the experiment, both shops used air curtains in the door as well as the normal heating to keep the shop warm when the door was closed.

The heating systems were set to come on when the temperature in the shop was below 19C and shut off when it reached 21C. In both shops, when the door was open the heating never shut off because the temperature never reached 21C. (Outside the average temperature was 6C - 10C, this was in March 2010). In fact the staff often complained they were cold when the door was open (and in Rymans the cashier got an extra heater under their desk).

With the door closed, the electricity consumption was reduced by an average of 34 kWh/day in Cambridge Toy Shop  and 107 kWh/day in Rymans (Rymans is a larger shop with a wider doorway). Commercial customers pay somewhat less for their electricity than homeowner do and so in terms of hard cash the toy shop savings would be about £3/day and for Rymans it would be £10/day (3). The researchers estimated the annual savings based on actual weather over 5 years and these came to £500 - £600 for the Toy shop and £1300 - £2000 for Rymans. That is not very much in comparison with the store turnover: probably not enough to make it worth taking a risk that trade will drop with the door closed.

The key question is, then, does the closed door discourage people from coming in or not? Unfortunately the research did not find a clear answer. The experiment only covered 28 shop days of which 11 had the door open (4). However, based on this small sample, Rymans saw 20% more people enter when the door was closed but the toy shop had about the same proportion fewer people come in. It is possible that the door monitors were not totally accurate and the bottom line is the number of transactions made: Rymans saw no difference to speak of in terms of actual sales but the toy shop had about a fifth fewer transactions with the door closed. This is a huge difference. Clearly, for the toy shop but not for Rymans, the open door policy is more profitable (provided the staff can cope with the cold)

Overall, it seems that despite the large potential for energy savings the money argument for closing shop doors is not very strong; the impact on the number of customers coming in is much more important. Customer behaviour is key;  in one case customers did seem to be put off the by the closed door, in the other not.

Maybe the toy shop gets a higher proportion of custom from people with push chairs who are less likely to drop in spontaneously if they see a closed door. Maybe they expect to have a hard time opening it whether or not this is actually true. If their expectations were that the door would be easy to open then they might not be so easily deterred.

Many shops have signed up to the Close the Doors campaign but there is still a way to go. If we want shops to close their doors we have to show them that we will not be deterred. In fact, we should be more likely to go into a shop with a closed door in the expectation that it will be nice and warm inside.



(1) Making access to goods and services easier for disabled customers: A practical guide for small businesses and other small service providers. Disability Rights Commission
(2) based on 2008 figures from DECC as cited in the Close the Doors report
(3) based on 9.7 p/kWh as used in the report.
(4) On other days it was not possible to be consistent. For example doors had to be left open for deliveries, and staff did not always co-operate when it was very cold.