Out of the box: sustainable product design

It’s a tricky business working out how much time people really spend thinking about sustainability when buying a new product. There’s no doubt it’s moved up the agenda in the last few years yet few would argue it’s as big a driver as price and quality.

A report from PriceWaterhouseCoopers made in 2008 concluded that while the majority of British consumers were changing their behaviour due to concern for the environment, almost half were unwilling to pay more for green products. And that was before the recession.

Miniature: the compact design of Renault’s Twizy holds an all-electric engine
Miniature: the compact design of Renault’s Twizy holds an all-electric engine

Despite this, it’s become rare to find a company that’s not addressing sustainability issues in some way. And not just because they want to be seen to be green: there’s money-saving motivation for creating a more environmentally friendly product.

’When we thought about sustainability in the past it was about landfill and waste, and then it was about renewable resources because the oil supplies suddenly became an issue,’ said Neil Hirst, design director of consultancy Seymour Powell.

’The reality is, people wanted to use less plastic because it was becoming increasingly expensive, so on the face of it they could claim it was about sustainability but actually it was cheaper. That realisation was one of the biggest motivations for people latching onto it.’

Innovation:Riversimple’s hydrogen fuelcell vehicle was designed from scratch
Riversimple’s hydrogen fuelcell vehicle was designed from scratch

Another driver is often legislation, particularly in Europe where EU regulations are set to bring in ever-increasing requirements for energy efficiency and recyclability. Investing in extra research and going beyond current limits could save money in the long run and put a company ahead of the competition when the next set of targets comes in.

If firms are serious about sustainability, then product design is the place to start thinking about it

But it’s not all about cutting costs and there is still a demand for sustainability from consumers, according to Rachel Harker, business development manager at product design specialist Cambridge Consultants. ’While there’s lots of evidence to suggest consumers aren’t prepared to pay more for a green product, given the option between two products that have the same features they will pick the green one.’

If companies are serious about sustainability, then product design is the place to start thinking about it, she said, arguing that around 80 per cent of the impact of a product is determined at its design stage.

’Before anyone gets a pen out we try to evaluate what the impact of the product is going to be. It relies on looking at competing products and using those as a model or looking at your previous products or creating a very rough model of what you think this product’s going to be.’

Whizzing around: the Twizy from Renault
Whizzing around: the Twizy from Renault

This process can be simpler if you’re redesigning an existing platform and already have information to work with as well as a design that is familiar to customers and will perhaps be more readily accepted. But sometimes it can be more efficient to start from scratch and create an entirely new product.

“A part that’s heavier or more expensive might give you a vehicle that’s lighter or cheaper ”


For its upcoming ZE range of electric vehicles Renault decided to pursue both methods, creating versions of its existing van and mid-size saloon platforms (Kangoo and Fluence), as well as two new hatchback and miniature lines (Zoe and Twizy).

Choosing one of these routes depends on the potential market for the product, said Andy Heiron, Renault’s head of electric vehicle programmes, who recently gave the annual Clerk-Maxwell lecture at the Institute of Engineering and Technology (IET). ’[The hatchback] is the biggest segment in the market and the one where, due to the usage characteristics, we can see a very significant opportunity for an all-electric vehicle.’

But Renault expects to sell far fewer electric saloons, he said.

’You’re not going to have the return on your investment that makes it worthwhile designing a vehicle from the ground up. But when you’re taking a product that’s already been designed and electrifying it, there are some specific considerations, but it gives you a relatively low cost.’

A company taking the opposite approach is new manufacturer Riversimple, which aims to make its hydrogen fuel-cell vehicle more sustainable than traditional cars in every respect. ’Trying to incrementally adapt things that have been designed to solve a different problem is not nearly as efficient or effective as starting from scratch with a solution for the problem you face now,’ said the company’s founder Hugo Spowers.

To do this you have to consider the design of the product as a whole, rather than just comparing individual subsystems, he argues, and this requires good simulation software so you can try out different models without building every one.

’A component that’s heavier or less efficient or more expensive might give you a vehicle that is lighter or more efficient or cheaper,’ he said.

’We’re interested in optimising the whole system and to do that you’ve got to try out all sorts of different alternatives in the car and see what gives you the best performance.’

When running simulations there are four main elements of a product that can impact the environment, according to Harker at Cambridge Consultants: materials, production, usage and disposal.

’Typically speaking, for a consumer product, nine times out of 10 most of the impact will happen during the use phase, and that tells you where you need to direct your efforts,’ she said.

But these categories aren’t completely distinct. For example, different materials have different environmental production costs but they can also impact a product’s energy usage due to their different weights, alongside the internal efficiency of the item.

Similarly, the recyclability of the materials you choose can impact the manufacturing process. Riversimple plans to manufacture its cars from a carbon-fibre-based composite material that will allow the company to reduce the weight of the car and provide a high degree of strength. But it also wants to develop a closed-loop manufacturing process so that old cars can be recycled.

’One of our biggest problems is with composite materials,’ said Spowers. ’We’re working with Epea in Hamburg and other companies to develop completely closed-loop material systems. What you want is, like steel, to be able to melt it down and start again but you can’t do that yet. We’re going to have to start with epoxies and Epea reckon we can recapture about 85 per cent of that, but the target is 100 per cent.’

Sometimes companies can also do a lot more with their factories than they can with their product, argued Hirst at Seymour Powell. ’If they put in new filtration systems and recycling systems for their water and recycle their heating and so on, those issues can have a much greater impact on the environment,’ he said.

The interconnected nature of these different elements highlights a big problem: just how do you establish what is the most sustainable route to take? It’s difficult to compare the impact of reducing the weight of a product by changing from metal to plastic and thereby using less petrol in transportation, with the impact of extracting oil from the ground to make the plastic and then potentially being unable to recycle the material.

’No matter how much of a desire to be environmentally friendly there is, the biggest problem is the absence of a consistent tool for measuring the impact. Carbon footprint is just one thing; it doesn’t give you the other measures,’ said Hirst. For now, firms will have to settle either for what they believe to be the most sustainable option, or take the more common route of doing what saves them the most money.

in depth

built to last

Riversimple claims true sustainability is achieved by leasing out productsSustainable product design should be about reducing consumption but manufacturers always want to maximise their output. One seemingly radical solution to this is turning the sale into a lease, giving the manufacturer a continuous revenue stream while encouraging them to build products that last and can be easily recycled.

That’s the model Riversimple plans to use and founder Hugo Spowers said that if chemical companies leased their products in a similar way we’d soon get more sustainable materials. This isn’t as an unusual idea as it first seems. Renault is planning a lease scheme for its electric vehicle batteries and aircraft engine manufacturers already operate along similar lines. Perhaps the key to sustainability is designing a better business model, as well as a better product.