Retrofit: Face challenges of urbanisation

Cities are resilient beasts.

Byzantium, for instance, was already 1,000 years old and home to several hundred thousand people by the time the Roman Emperor Constantine decided to make it the new capital of his empire in 324AD.

And in the 1,600-plus years since, the city has thrived against the odds, overcoming conflict, disease and natural disasters to become modern-day Istanbul, one of the 25 largest metropolises in the world.

Like its counterparts, the city’s survival is a testament to humanity’s extraordinary ability to adapt and innovate.

But also in keeping with the globe’s other great urban centres, Istanbul’s biggest challenge is perhaps yet to come.

That’s because urbanisation has reached a tipping point. Although cities take up just 2 per cent of the world’s land mass, they consume almost 80 per cent of its energy and are responsible for about two thirds of CO2 emissions. And with 180,000 people migrating from rural to urban areas every day - and some 70 per cent of the world's population expected to be living in cities by 2050 - metropolitan authorities will face enormous social and environmental challenges over the coming decades. 

Solving these problems can involve radical solutions.

The most revolutionary is starting from scratch. 

Newer urban hubs such as Malaysia's Forest City and South Korea's Songdo are examples of this approach. In such cases, authorities have been able to plan with a blank sheet of paper and harness the latest sustainable technologies in areas such as energy efficiency and innovative residential and commercial real estate.

Unfortunately, that doesn’t work for older, established cities. Because they have to deal with ageing building stock and infrastructure, older urban centres find huge overhauls are often costly, complex and cause too much disruption.

That’s where an approach called retrofitting can help.

“Cities face the perfect storm of climate change, population growth and resource scarcity. The radical solution is to knock them down and rebuild them – but this will never happen,” explains Dr Richard Miller, a leading advocate of the retrofit approach and founder of urban innovation consultancy Miller-Klein Associates.

“Cities are a combination of people and infrastructure, and both have memory. We must deal with their persistence. Very few cities are designed from scratch. Rather, they evolve. So you have to focus on evolutionary changes."

Retrofit could play a key role in Europe, given the continent's ageing infrastructure and housing stock. A recent report by the UK’s Institution of Engineering and Technology (IET) and the Nottingham Trent University, for which Dr Miller was the lead author, highlighted this problem.

It says the UK – where less than a quarter of homes were built after 1980 – will need to retrofit at a rate of more than 1.5 homes every minute in the next 30 years if it is to achieve its carbon emission reduction target by 2050².

Dr Miller is leading calls for UK authorities to implement “deep” retrofits – one-off upgrading of entire buildings – which he says is more cost effective over a 30-year horizon than smaller, piecemeal changes.

“There are various grants to improve the existing housing stock, but most of the solutions will have to be replaced before 2050,” he says. “For example, they encourage you take out the old gas boiler and replace with an energy efficient one. But there will be no gas in the 2050 energy mix."

Dutch cities including Amsterdam, Rotterdam and Utrecht are already phasing out gas boiler in favour of electric heat pumps before a national ban on natural gas by 2050.

Although some deeper retrofit programmes involve large upfront costs, municipal authorities typically provide inexpensive financing, while the work eventually pays for itself though energy savings, Dr Miller says. 

Warmer, healthier and cleaner

A pilot deep retrofit programme in the UK has cut carbon emissions by as much as 80 per cent compared with 1990 levels³.

But the benefits of retrofitting go beyond just cutting emissions. Retrofit can also improve the health and well-being of city residents, which can in turn reduce medical and social care costs.

The cost savings can be significant. Take housing quality.

The IET report estimates that poor-quality housing costs the National Health Service, the UK’s public health services, some GBP1.4 billion a year in additional health treatment. Better insulation and the incorporation of other energy efficient technology could reduce social care costs by up to GBP4,500 per person and halve the number of visits to the doctor⁴.

But for retrofitting to be successful, co-ordination between the private and public sectors is key. 

As Dr Miller explains, cities have existed for centuries, but they are never too old to transform themselves.