The retail sector has a well-deserved reputation for energy gluttony. Martin Clowes of Elementa Consulting talked to four big retailers to find out what they’re doing to green up their acts

The retail sector is commonly regarded as profligate with its energy, and there is no doubt that shops are responsible for the emission of a lot of carbon. So is new energy legislation going to change what they do? I spoke to the energy managers at Asda, Dixons, WH Smith and GUS, which owns Homebase and Argos, and to get a response.

Money tends to be more of a business priority than energy efficiency, but the two go hand in hand. The increasing cost of energy is a driver in itself – the price has risen 30% in recent times and this is becoming a real business issue. All the firms surveyed are running energy initiatives ahead of legislation because of the rising cost of energy. In most cases they already have some corporate governance policy on either the environment or carbon.

Asda, for instance, has a target to reduce overall carbon consumption 30% in three years, and that includes “process” consumption generated by, for example, refrigeration. Part L 2006 only refers to the envelope and fixed (non-process) services, so they are ways of saving energy over and above complying with Part L.

All the retailers are concentrating on good housekeeping measures as the main ways to reduce energy costs; this includes improved controls, metering, plant and lighting technology.

In terms of air-conditioning, technology has moved ahead of regulation in the UK. Regulations in other countries, as well as competitive pressures, are driving an international market. Heat pumps with inverter compressors, variable air volume, inverter drives are in common use, and free fresh-air cooling is becoming more popular.

Part L pre-2006

Stores built to the 2002 Part L regime seem to have performed well, as they have better air-tightness than older buildings. The 2002 Building Regulations require metering of different uses of energy. In practice, this has had little effect as it is difficult to get reliable information. Generally, meters are installed but they are often tucked away in a cupboard, so little notice is taken of them. Logbooks, another 2002 requirement, are rarely provided, and the maintenance regime would not favour them anyway. This has not been enforced through the compliance process.

Part L2A 2006

Most retailers welcomed the new-build provisions in principle. For new shells, developers and landlords need to consider what the tenants’ energy mix is going to be, and the shell has to be designed to allow for this. Also, the retailer will want the flexibility to move on and assign the lease to another retailer, which will need to know that its own energy needs can be accommodated within the shell. This means that developers need to make appropriate assumptions for the design of their retail units. So, if the developer has assumed a good services performance to offset poor shell performance, the tenant has a big problem.

Part L pays a lot of attention to air-tightness and thermal bridging. For a shop with high energy inputs for lighting and so on, air-tightness and the envelope affects mainly heating, which makes up about 10% of retailer’ energy use. So Part L 2006 is not going to have a major effect on retailers’ energy bills.

The Simplified Building Energy Model, the software tool used to calculate compliance with Part L, has optional lighting standards. These are relatively easy to comply with as long as the store meets the basic lighting efficacy assumed in the SBEM. So the merchandisers’ dream of 1600 lux (at 35 W/m2 average across the store) complies with legislation. It’s the efficiency of the individual light fittings that count, not how many of them you put in.

The requirement for increased energy metering is beginning to have a big effect. One retailer is looking at linking its shops’ energy performance to the shop managers’ PC screens, giving them simple choices as to how to manage their energy. There is a huge amount of development of control systems going on in the background, and retailers expect to be incorporating, targeting and exception-monitoring as part of future programmes.

If the developer has assumed a good services performance to offset poor shell performance, the tenant has a big problem

Part L2B 2006

Retailers find the wording of this legislation unclear on what to specify for refitting shell-and-core buildings and high street shop units. One retailer is looking at a small store fit out of a fully glazed unit, in which an all-electrical heating installation will comply under L2B. This is counterintuitive, but it is allowed.

There are potentially much higher costs from compliance. Most of the national retailers’ buildings are air-conditioned, and plant is replaced every 10 to 15 years. The performance standards for replacement plant set out in the second tier compliance guide are not particularly onerous, but the process is, so there is a huge amount of compliance work to go through with little result. What used to be a straightforward maintenance operation has now become one where a significant amount of design and cost checking is needed. And the installer self-certification scheme has not got going.

One retailer has a range of stores that it intended to refit with air-conditioning. Again, this is now a much more complex process. To achieve a payback of period of 15 years, they would need to put in additional wall and roof insulation, but in many cases the increased structural loadings would not be possible. Usually the retailer doesn’t own the building either, so they are unlikely to be excited at the prospect of providing a free building upgrade for the landlord.


Some approved inspectors are not in a position to sign off the compliance and so far, there are few consultants able to offer a compliance service. There are concerns that a market will develop for “cheap compliance” where people will pay lip service to the regulations, relying on a raft of supporting documentation prepared by a chain of partially qualified or “on-side” organisations, without actually achieving the standard. The immediate consequences of detailed non-compliance are unlikely to be severe owing to a general lack of knowledge and the cost estimate payback factor. Subsequent liability problems will be complex, but are some time off.

Developers’ new shell designs

So far, retailers are not seeing any real attempt by developers to offer really low energy stores with, say, saw-tooth, north-lit roofs to improve daylighting and reduce lighting energy, or to make use of natural ventilation. Mixed-use and mall developments could give much more scope for the retailer to improve performance by allowing free cooling, CHP generating plant and energy ringmains connecting retail, commercial and residential.

European Public Buildings Directive

This legislation will require public building to carry a label stating how energy efficient they are. This is going to be is a big issue. It is obvious that a busy store is going to use far more energy than a quiet one. It could also bias one retailer against another and some have concerns that lobby groups may use these ratings to unfairly target particular retailers. Other retailers welcome the comparisons because they reckon they are ahead of the game.

PPS 22

Renewables have not made a big impact yet but many retailers have already incorporated wind turbines and photovoltaic panels and others are looking at exemplar projects.

Regulations August 2006