How can cities ensure healthy architecture in an era of rapid population growth?

A new building emerges on Place de la Concorde, Paris. Image: Getty.

Worldwide population growth and mass migrations are putting the infrastructure of many cities under strain. With city governments under pressure to provide more housing and work spaces, people can end up living and working in poorly designed or low quality buildings.

Since the beginning of human civilisation, people have been striving to create a beneficial built environment. Take Neolithic buildings, for instance: they were purposefully orientated to catch the sun and allow for ventilation. Later, over 3,000 years ago in Crete, the Minoans built underground sewage systems to avoid plagues. So too did the Romans, who also used underfloor heating systems and aqueducts, and provided baths throughout the empire to keep the population in good health.

Slums in Wentworth Street, Whitechapel. Image: Wellcome Images/Wikimedia Commons.

Despite these early successes, maintaining healthy conditions became much more difficult in times of rapid population growth. During the industrial revolution, for instance, many cities quickly became overpopulated. With growing industries, employers were under pressure to accommodate more workers, and decayed or unfit buildings were used to host increasing numbers of tenants.

In the UK, living conditions reached such poor standards that the government passed a number of laws to improve public health. A similar sanitation project took place in Germany, at around the same time. These strategies provided many cities with outstanding green infrastructure such as parks and boulevards, which still bring many health benefits to those who can access them today.

Sick building syndrome

But in recent years, “sick building syndrome” has become a worry worldwide. Research has shown that headaches and respiratory problems among office workers were directly related to the use of air conditioning, poor ventilation and other widely-adopted technologies. Today, health professionals and designers have plenty of evidence to show that some buildings can harm people, both physically and psychologically. Yet ensuring buildings are “healthy” is a difficult task.

In the UK, some features such as ventilation and heating have to meet certain standards. But other design features, which are known to have a big impact on human welfare, are still not regulated. For example, there’s evidence that exposure to natural light and direct contact with nature have a positive effect on school exam results – yet there’s no legislation which says they must be a feature of learning environments.

And while scientists are constantly experimenting to grow our knowledge of the impacts that buildings have on human health, laws and regulations tend to develop more slowly. This means that even new buildings can be inadequately ventilated, or suffer from a lack of natural light – even though we now know that both cause symptoms of ill health.

A lack of natural ventilation means viruses are retained in the air, while a lack of natural light can affect brain functions. In Britain alone, these design pitfalls are adding to the stress on the NHS, and costing the economy an estimated £24.6m due to lost working days each year.

What’s more, as the Grenfell Tower disaster made awfully clear, technical difficulties and budget constraints can mean refurbishments are made using incompatible or inappropriate building materials, resulting in homes which simply aren’t safe to live in.

Tech fails

Architects aim to deliver sustainability by reducing energy consumption. There is a huge range of technologies which can help achieve this. But relying too heavily on such solutions can backfire: in 2016, researchers found that many homes had been built to be airtight, in a bid to meet energy efficiency targets. This can cause CO₂ and other pollutants to build up indoors, which in turn has adverse effects on residents’ health.

Human factors – including how we navigate and socialise within the built environment, and how our body responds to it – also have a big impact on the overall efficiency of buildings, and the sustainable technologies which go into them. Research has shown that people don’t always operate equipment as instructed – rather, they naturally look for comfort through more instinctive behaviours.

For example, when we feel a room is overheated, we tend to open windows to gain instant refreshment, rather than turning the thermostat down. This reduces the effectiveness of low-carbon technologies. So even buildings that have plenty of features to enhance energy efficiency can still be unsustainable, if people don’t use them properly.


The power of good design

Design is still the most powerful tool an architect can use: simple design measures, such as opening buildings towards sunnier aspects or adding ventilation in strategic locations to make the most of prevalent winds, are tried and tested techniques which can help to deliver healthier, more sustainable buildings.

Yet this approach comes with its own issues. Inner-city locations are often difficult to build in, because of their small size and crowded surroundings. Sometimes, architects will prioritise creating a “landmark” exterior, at the cost of a healthy interior. Other times, architects misinterpret planning guidance and recommendations, which can be vague and unspecific. Likewise, planning restrictions can actually be enforced to the detriment of the overall building quality.

The ConversationAt the moment, planning laws aren’t strong enough to provide truly sustainable environments that take human factors into account. Reform is long overdue, and designers, builders, planners and health professionals need to make a greater effort to find a more collective and coordinated way of working. But as a society, we must take joint responsibility: we can all make a start by learning how to change our our behaviour, to make the human aspects of sustainability a central part of our lives.

Laura B Alvarez, Architectural Technologist and Urban Designer, Nottingham Trent University.

This article was originally published on The Conversation. Read the original article.

 
 
 
 

How collecting food waste could slow climate change – and save us money

Cleaning up. Image: Getty.

Food waste is a global problem, and one that’s driving climate change. Here in the UK, the country’s biodegradable waste goes to a landfill, where it breaks down to produce methane, a gas that is roughly 30 times as bad as carbon dioxide.

And yet there’s a simple solution. With the exception of garden waste, which often contains lignin from woody matter, all biodegradable materials, including much of our food waste, could instead be processed in anaerobic digesters. This decomposition in an atmosphere devoid of oxygen produces biogas, which can then be used to generate heat and electricity.

This is more or less the same process that takes place in landfill sites, except that the biogas can’t escape from an anaerobic digester as it can from landfill – meaning the breakdown of the organic matter takes place in an environment that is enclosed and controlled.

The result is biogas consisting of 60 per cent methane and 40 per cent carbon dioxide, which can be burnt in order to generate heat or used as a fuel for vehicles. It could also be used to generate electricity after the biogas has been scrubbed, which can then either power the anaerobic digester or be exported to the national grid. The process also produces digestate, a solid and liquid residue that can be returned to farmland as a soil conditioner. The amount of biogas and the quality of digestate varies according to what feedstock is used in the digester.

This process is already widely used both across Europe – particularly in Denmark, Sweden, Germany and Austria – and elsewhere globally, particularly in India and Thailand. What's more, this move towards separate food waste collection is already happening in countries outside the UK, and its momentum is increasing according to the World Biogas Association. Already, major cities, including New York, Paris, Oslo, Copenhagen, Auckland, San Francisco, Mexico City and many others are regularly collecting food waste from their citizens. The decisions to do so are usually taken at city level, but enabling legislation from national governments assist in this.


At present the UK is lagging behind. Only 109 local authorities in England, about 33 per cent of the total number, collect food waste as of May 2018, according to the Anaerobic Digestion and Bioresources Association (ADBA). Yet making a separate food waste collection mandatory across the UK and running the food waste through anaerobic digesters, could supply enough biogas to generate 36 per cent of UK electricity, according to a 2007 Friends of the Earth report. This percentage could be increased again if food waste from restaurants, cafeteria and retailers was also collected. 

ADBA’s research also suggests that universal separate household food waste collections would trigger the construction of around 80 new anaerobic digester plants for food waste processing. This would add an extra 187 megawatts equivalent (MWe) of capacity, powering 285,000 extra homes – representing all the homes in a city the size of Glasgow. Data from WRAP suggests that further food waste collection from businesses would add around a further 10 per cent, depending on the quality of the feedstock collected and what exemptions were applied (for example, it might only apply to businesses collecting more than 50 kilograms per week or the lower threshold of 5kg).

A 38 per cent improvement in food waste collection from flats in Ealing alone could generate £26,000 of annual savings for the London borough, £28,000 in revenue for a local anaerobic digester (based on electricity sales to the national grid) and reductions in carbon dioxide emissions of around 270 tonnes, found Londoners Lab, a collaborative project consisting of Greater London Authority, University College London, Ferrovial Services Centre of Excellence for Cities and Future Cities Catapult.

ADBA has been campaigning on this issue for a while, but the good news is that the government finally signalled its intention to introduce separate food waste collections in its forthcoming Resources & Waste Strategy, which will ensure that all homes and suitable businesses in England will have access to food waste collections by 2023. The next step, following the government announcement, is a consultation, but it is widely acknowledged that additional funding would be needed by local authorities to achieve this, as the business case isn’t currently strong enough.