It's time to make carbon negative buildings the norm

Climate change has entered into a new phase that could last generations even if governments act to curb human activity that leads to global warming. But the Habitat III New Urban Agenda agreed ten days ago offers a chance for the built environment to become negative carbon. Buildings can now begin to withdraw carbon dioxide from the atmosphere. This article gives a few tips on how.

Globally averaged concentration of carbon dioxide in the atmosphere reached the symbolic and significant milestone of 400 parts per million for the first time in 2015 and surged again to new records in 2016 on the back of the very powerful El Niño event, according to a new bulletin issued last week from the World Meteorological Organization's annual Greenhouse Gas Bulletin.

"The year 2015 ushered in a new era of optimism and climate action with the Paris climate change agreement. But it will also make history as marking a new era of climate change reality with record high greenhouse gas concentrations," WMO Secretary-General Petteri Taalas said in a statement.

The data "predicts that carbon dioxide concentrations will stay above 400 ppm for the whole of 2016 and not dip below that level for many generations," the WMO said. “The El Niño event has disappeared. Climate change has not. Without tackling carbon dioxide emissions, we cannot tackle climate change and keep temperature increases to below 2^oC above the pre-industrial era. It is therefore of the utmost importance that the that the Paris agreement does indeed enter into force well ahead of schedule on 4 November and that we fast-track its implementation.”

The El Niño event triggered droughts in tropical regions and reduced the capacity of “sinks” like forests, vegetation and the oceans to absorb CO₂. Besides this it also led to an increase in CO₂ emissions from forest fires. According to the Global Fire Emission Database, CO₂ emissions in Equatorial Asia – where there were serious forest fires in Indonesia in August-September 2015 - were more than twice as high as the 1997-2015 average.

Habitat III's New Urban Agenda

But there's hope. Habitat III, which took place in Quito last week with around 36,000 people attending from 167 different countries, adopted the New Urban Agenda which, amongst other things, urges cities to tackle climate change.

Joan Clos, the Executive Director of the UN Human Settlements Programme (UN-Habitat), called the Agenda "a common roadmap for the 20 years to come” at the closing plenary of the conference.

Cities are both the source of most of the world’s carbon-dioxide emissions and the place where the most impactful interventions can occur — to reduce automobile driving, improve energy-efficiency in buildings and switch to renewable energy sources, among other opportunities.

“By making the Paris Agreement one of its antecedents and quoting its long-term goal, the New Urban Agenda is acknowledging the climate challenge in cities, and putting climate action at the core of urban policies at national and local levels — and that’s a good thing,” said Mark Watts, executive director of the C40 Cities Climate Leadership Group.

The agenda does not bind Member States or city governments to specific targets or goals, but is rather a “shared vision” that set standards for transforming urban areas into safer, resilient and more sustainable places, based on better planning and development.

The Quito Implementation Plan is now set up to support the outcomes of Habitat III and the New Urban Agenda.

Negative carbon buildings

Amongst the potential strategies to help with the Quito implementation plan is for building specifiers, developers and architects to generate buildings which are at least zero carbon on balance, when totalling the carbon impacts of materials, construction, use and demolition. But what does this mean?

Some features of zero or carbon negative buildings are to:

• minimise the use of fossil fuel energy during the supply chain and process of construction;
• encourage the use of materials which store atmospheric carbon in the fabric of the building;
• construct and manage it in such a way that it minimises the emission of greenhouse gases during its lifetime and eventual demolition;
• encourage the capture, generation and even export of renewable energy;
• make the structure very airtight;
• make the structure breathable;
• make it durable, resilient, low-maintenance, fire- and weather-resistant;
• incorporate a large amount of insulation. 

The ideal features of zero-carbon, solar buildings.

Such a building could, over its lifetime, become zero carbon, or even negative carbon by generating enough power to more than make up for the fossil fuels it has used and storing atmospheric carbon in its structure.

Neighbourhood design

From a planning angle, different neighbourhood layouts for developments are appropriate depending on the regional climate as shown in these figures:

 Hot climates: inappropriate (left) and appropriate (right) spatial layouts for settlements. Organic, non-grid layouts provide shade and can be designed to block winds, preventing issues with wind funnelling. Grid layouts borrowed from other climates, and wide spacing of buildings, do not provide shade or wind shelter.

Higher latitudes: in this housing estate each property has both privacy and an equator-facing aspect and roof to maximise the potential for the use of solar energy. Grey circles are trees, grey lines are hedges (preferably) or walls.

Carbon intensity

On average the carbon impact of the construction of conventional buildings is between 10 and 20% of their use during their lifetime. But it is self-defeating to construct a zero carbon building with materials that cause high carbon emissions in their manufacture.

Conversely it is ideal to use materials which lock up atmospheric carbon, for situations where well-performing and suitable alternatives exist, usually made from natural cellulose-based materials. (Plants absorb atmospheric carbon while growing and 'lock it up' in their mass.)

Steel is a possible exception, despite its high embodied carbon, as it is long-lasting, but many large and high-rise structures are now being made using frames made of timber products.

‘Natural’, ‘green’, ‘bio’ or ‘renewable’ building materials can be classed together as ‘cellulose-based’. Amongst their benefits are that they:

• lock up atmospheric carbon in the building;
• have varying degrees of insulation ability;
• are easy to work with;
• make structures that are breathable.

They are also biodegradable or easily recycled at the end of the building's life and may support local agroforestry.

Wood has a greater tensile strength relative to steel – two times on a strength-to-weight basis – and has a greater compressive resistance strength than concrete.

Sustainably sourced timber and timber products specially designed for structural use must be specified. These include glued laminated timber ('glulam') and Cross-Laminated Timber (CLT).

The tallest building in the world made with timber frame is 14 storeys high and is in Bergen, Norway. It uses metre-thick columns of glulam and CLT, plus two concrete decks above the 5th and 10th floors. See the video below.


Glulam can produce columns, beams and curved, arched shapes and has a much lower embodied energy than reinforced concrete and steel, although higher than solid timber.

CLT is an engineered timber product with good structural properties and low environmental impact able to provide dry, fast onsite construction, with good potential for airtightness and a robust wall and floor structure suitable for most finishes internally and externally. It requires only limited new site skills and can be assembled without the use of adhesives using mechanical fixing. Its low weight means that a high degree of offsite manufacture is possible.

Other useful timber products include:

• Plywood, wood structural panel;
• Oriented strand board (OSB);
• Laminated veneer lumber (LVL);
• Parallel strand lumber (PSL);
• Laminated strand lumber (LSL);
• Finger-jointed lumber;
• I-joists and wood I-beams – "I"-shaped structural members designed for use in floor and roof construction;
• Roof trusses and floor trusses.

Other natural carbon- negative materials currently used in construction include:

Material	Application
Flax	Roofing insulation
Hemp fibres	Insulation
	Medium density fibre board
	Oriented strand board
Hemp shiv	Monolithic construction ofwalls, floors and roofs
	Insulation
	Panel construction
Jute	Carpet
	Plastering mesh
	Scrim
Paper	Recycled and shredded forinsulation
	Mixed with cement to formblocks
Reed	Thatching
Reed mats	Plastering base (like laths)
Sisal	Carpet (mixed with reinforcedcement in some countries)
Straw	Bales as building blocks
	Wall panels
	Thatching

For reporting purposes, it may be useful to report the carbon storage capacity of a building, to add to the carbon saved from using renewable energy to heat and power it. For buildings a web-based calculator like the one on this page may be used.

Phase shifting Phase shifting is another useful tool for building designers. It denotes the time taken for an extreme external temperature to reach the interior, travelling through the building envelope.

The aim of passive cooling in hot, non-humid areas is to have a phase shift of 12 hours, so that the midday heat only reaches the interior in the middle of the night. With good amplitude dampening, its effect will also be very much moderated.

Some of the stored energy in the fabric is thus automatically transferred back outside, ensuring that temperature fluctuations and extremes on the inside are much less than outdoors.

Amplitude dampening and phase shifting should be particularly observed in roof areas. These may get very hot and so require large thicknesses of insulation with low thermal diffusivity. Aim for an amplitude dampening value of 10 (TAV 10%) and a minimum phase shift value of 10 hours.

There is now no excuse for building specifiers and designers not to give us at least zero carbon buildings.

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David Thorpe is the author of:

• Best Practices and Case Studies for Industrial Energy Efficiency Improvement (with Oung, K. and Fawkes, S. UNEP, 2016)
• A London Conversation: Business Briefing on Green Bonds (The Fifth Estate, 2015)
• The One Planet Life (Introduction: Jane Davidson. Routledge, 2015)
• Earthscan Expert Guide to Energy Management in Buildings (Earthscan, 2013)
• Earthscan Expert Guide to Energy Management in Industry (Earthscan, 2013)
• Earthscan Expert Guide to Solar Technology (Earthscan, 2011)
• Earthscan Expert Guide to Sustainable Home Refurbishment (Earthscan, 2010)

How Habitat III will kickstart a revolution in cities

Habitat III – the United Nations Conference on Housing and Sustainable Urban Development, which took place in Ecuador's capital, Quito, last week – solved the question of how cities can meet the needs of their expanding populations while at the same time being inclusive and sustainable.

The "New Urban Agenda", adopted at the event, will provide a road map for urban development over the next 20 years. It will help our expanding cities surmount the huge challenges they face in everything from health services and schools to public transport and energy.

Local government representatives including over 200 mayors and delegations from 500 cities met at the end of the previous week at the 5th UCLG Congress World Summit of local and regional leaders held in Columbia’s capital city, Bogotá, to prepare for this important event, moving on to the 2nd World Assembly of Local and Regional Governments on Sunday in Quito itself.

The Summit issued a demand for cities' role to be taken more seriously at national and international levels. United Cities and Local Government (UCLG) – the equivalent of the United Nations for cities and an umbrella body for local government around the world – sees from now on an unprecedented opportunity for cities' needs to be represented at the global level.

They released a manifesto called “A Seat at the Global Table: Local Governments as Decision-Makers in World Affairs,” which argues that, compared to national governments, municipalities are the closest to everyday citizens and know the needs of their cities more intimately than national-level bureaucrats.

They also released a more detailed document called “The Bogotá Commitment”, which further describes how local governments can contribute ideas and play a role in the global debate on a more sustainable urban future.

It states that “the answers generated within urban settlements and territories will pave the way for global solutions”.

Bogotá also saw the former Johannesburg mayor, Parks Tau, elected as president of UCLG. Tau's remit is to drive the global local government fraternity to achieve UCLG's key objectives, amongst which is implementing the Paris Accord on Climate Change and the New Urban Agenda.

Act locally, think globally

The consensus among urban leaders is that dealing with the world’s most complex issues, such as fighting climate change and poverty, requires coordinated solutions at the global and local levels.

The Bogotá Commitment calls therefore for local and regional leaders to lead the transition toward low carbon, resilient cities and regions, and to develop new capacities and modes of leadership to respond to and take advantage of the host of new opportunities that are opening up for the achievement of the Sustainable Development Goals (SDGs) and the New Urban Agenda.

The Commitment calls upon city leaders to harness integrated urban and territorial planning to shape the future of cities and territories and ensure equal access amongst their populations to quality and resilient infrastructures and basic services. This means putting the ‘Right to the City’ at the centre of urban and territorial governance.

This will be a powerful tool for citizens to hold local authorities to account.

The Commitment also says that "Local leadership will only flourish if there is a national enabling environment for local and regional governments with adequate legal frameworks and resources, as well as a transformation of top-down approaches. Moreover, it can only succeed if the uneven decentralization found in many countries and regions is urgently addressed".

This would imply that national governments will have to relinquish some of their power and devolve it to city and region level.

This will require not only finance, but for cities to have improved control of their finances.

The Commitment therefore calls for a global fund for infrastructures, basic services and housing to help access finance from banks and markets, particularly in low-income countries, and it calls for action to permit easier access by cities to climate finance for making their infrastructure more resilient to climate change.

At the same time it calls for the establishment of improved financing systems that can reconcile financing with sustainability. In other words, for national governments to share more of their resources at local level – the figure of at least 20% of the total public budget is mentioned – over the next decade.

The overriding feeling is that national governments are out of step with what is happening at the local level: cities are growing in both population and economic prosperity but in many cases national governments continue to hold power over key aspects of urban development.

“The global governance system is no longer adequate to address the existing challenges the world is facing because these challenges are at the same time more global and local”, states A Seat at the Global Table, so it calls for a “paradigm shift in global governance”.

To help them achieve these goals, cities are therefore advised to make their international-relations capacity more professional, while national governments would become “allies” by passing legislation enabling them to do so.

“We’re asking for a true partnership,” said Denis Coderre, the Mayor of Montréal.

UN backing

The mayors’ call has the backing of Ban Ki-Moon, the UN Secretary-General. At the 2nd World Assembly of Local and Regional Governments, he spoke on Sunday of a “widely recognized need to support and empower local governments”.

“Decentralization and devolution of roles and responsibilities for local and regional authorities is an important trend,” he added, emphasizing to the mayors in attendance that “your role is growing by the year”.

This event brought together over 385 local and regional leaders, representing different global networks of local and regional governments, joined by representatives of local government organizations and partners, who came together to deliver the Second World Assembly’s statement to the Habitat III Conference and commit to contributing to the implementation of the New Urban Agenda.

They celebrated the inclusion in the New Urban Agenda of a reference to the Right to the City as part of a shared vision of “cities for all”; and UN Member States’ commitment to ensure many of the above demands, and more; for example to take measures to promote women’s full and effective participation at all levels of decision making in local governments.

They particularly see the New Urban Agenda as a tool to help implement in cities all of the Sustainable Development Goals (SDGs), not just the obvious one – SDG 11 – which is 'to make cities and human settlements inclusive, safe, resilient and sustainable'.

Two years' of hard work went into preparing for Habitat III. Hard on the heels of the Paris Agreement and the establishment of the UN Sustainable Development Goals, it promises to signal a step change in the way humanity responds to the twin challenges of planetary boundaries and social justice.

This is the first of two reports on Habitat III. The second will be posted soon.

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David Thorpe is the author of:

• Best Practices and Case Studies for Industrial Energy Efficiency Improvement (with Oung, K. and Fawkes, S. UNEP, 2016)
• A London Conversation: Business Briefing on Green Bonds (The Fifth Estate, 2015)
• The One Planet Life (Introduction: Jane Davidson. Routledge, 2015)
• Earthscan Expert Guide to Energy Management in Buildings (Earthscan, 2013)
• Earthscan Expert Guide to Energy Management in Industry (Earthscan, 2013)
• Earthscan Expert Guide to Solar Technology (Earthscan, 2011)
• Earthscan Expert Guide to Sustainable Home Refurbishment (Earthscan, 2010)

European Commission must be more ambitious in its energy efficiency targets says building sector

The European Commission should set a target for retrofitting all of the continent’s existing buildings to a “Nearly Zero Energy” standard by 2050. That is the request in a letter to the Commission signed by the chief executives of 42 major building firms and six industry trade associations.

The target would be enshrined in the upcoming revision of the Energy Performance of Building Directive and the Energy Efficiency Directive, which are currently under review.

Arguing that “businesses, investors, citizens, governments, all need a clear 2050 vision to put the ambition level of the Paris Agreement into practice”, they state that doing so would provide an opportunity to create jobs and economic growth.

The letter reads: “It is clear that the Paris commitment cannot be honoured without drastically reducing energy consumption in our buildings; the EU building stock emits over one-third of our CO2 emissions, three-quarters of our buildings are inefficient, and up to four-fifths will still be in use in 2050. We need EU wide action to drive the transformation of our inefficient building stock and make it a resilient component of the energy system of the 21st century.”

It continues: “EU wide leadership and action in the construction and building sector will spur European jobs and growth (in particular for SMEs, which make up 90 per cent of the construction sector). A high level political commitment for renovation will give industry the much needed signal and certainty to unlock investments, in turn removing some of the market failures.

“Most of all, making Europe’s buildings better through a mass EU-wide renovation movement will bring invaluable benefits to the whole of society by helping deliver something that every European citizen wants and deserves: a comfortable, safe and affordable home. This is a ‘win-win’ for Europe.”

This target is in line with the aims of the World Green Building Council’s Advancing Net Zero project to make all the world’s buildings ‘net zero’ of emissions by 2050. It builds on a push to double efficiency by 2030.

Launched in June, this program involves Green Building Councils from Australia, Brazil, Canada, Germany, India, Netherlands, South Africa and Sweden who will develop clear action plans, with an aim to launch a national net zero certification.

Energy efficiency package postponed

Despite the backing of the European Parliament, the European Commission appears reluctant to back energy efficiency.

At the beginning of this week it was slammed by the Coalition on Energy Savings for its announcement that the energy efficiency package will not be launched before the end of the year.

The package will define a target for energy efficiency for 2030 and extend the main elements of the Energy Efficiency Directive beyond 2020, as well as discuss buildings’ energy performance and financing.

“This delay undermines the credibility of the European Commission to drive forward the EU with big and compelling projects like energy efficiency, which delivers benefits for people and business and which is the EU’s first action to fight climate change,” secretary general of the Coalition for Energy Savings Stefan Scheuer said.

“[European Commission] president [Jean-Claude] Juncker must not hesitate to deliver on his promise to propose a more ambitious and binding energy efficiency target for 2030.”

The European Parliament has repeatedly called for a binding 40 per cent energy reduction target by 2030 in line with the already identified cost-effective potential for implementing energy saving measures. The target is currently set at a reduction of 20 per cent in energy use by 2020.

Energy efficiency mortgage scheme

Further backing the increasing desire for making European buildings more energy efficient, a new financing initiative, that would potentially offer better borrowing rates on mortgages for homebuyers purchasing more energy-efficient homes or carrying out energy-saving retrofits within properties, was presented by energy and building sector professionals from across Europe last week.

The European Energy Efficiency Mortgage was launched at the World Green Building Council’s “Build Upon” summit in Madrid by the European Mortgage Federation, which consists of the European Covered Bond Council with partners.

• See EU residents set to get cheaper home loans for energy efficient houses

The scheme effectively creates a “pan-European mortgage financing system” in order to make energy efficiency measures more accessible and affordable for home-buyers.

For banks and investors, the mortgage could allow for loans that represent a lower risk on the balance sheet and could therefore qualify for a better capital treatment.

It could also ensure that banks are able to recognise “energy-efficient” assets in their risk-profiling, which would begin to help the market price-in the added value of energy-efficient real estate.

The project is the first time a group of major banks and mortgage lenders have sat down with businesses and organisations from the building and energy industries to address the concept of energy efficient mortgages.

Creating a private bank financing mechanism to encourage the energy efficient improvement of households would be a key means of helping the EU to meet its energy saving targets.

Alongside the EMF-ECBC, the project partners are the Ca’Foscari University of Venice, RICS, European Regional Network of Green Building Councils, E.ON, and SAFE Goethe University Frankfurt.

Over the coming months, they will begin a mapping exercise in relation to existing or past financing initiatives, energy efficiency indicators and valuation practices, with a view to identifying best practices with which to move the project forward. It will explore the link between energy efficiency and borrower’s reduced probability of default and the increase in value of energy efficient properties.

The experts will meet again in Brussels in February 2017, followed by a public event at which the next stage will be decided.

Europeans can also generate half their energy at home

Continuing the news from Europe on energy and buildings, it also emerged last week that half of EU citizens – including local communities, schools and hospitals – could be producing their own renewable electricity by 2050.

A study by Dutch consultancy firm CE Delft that evaluated the potential of decentralised power generation across the continent found that 264 million people in Europe could be producing their own renewable electricity by 2050 and meet 45 per cent of the EU’s energy demand, provided the right regulatory framework is put in place.

Sweden looks like leading the way, with an estimated 79 per cent of the population being able to produce their own energy in 2050.

Germany and other EU countries like the Netherlands already champion energy production by households, which can sell surplus electricity back to the grid at a guaranteed price.

“But in Spain, there is a ‘sun tax’ which makes it very expensive to install solar panels on your roofs or have energy storage at home. And there is only a handful of cooperatives,” said Sebastian Mang, climate change and energy officer at Greenpeace EU, which is among the organisations behind the study. “Yet across Germany, you see solar panels on the roofs and hundreds of energy cooperatives flourishing.”

The organisations are calling for the European Commission to enshrine so-called “energy citizens” at the centre of the EU’s Energy Union initiative.

David Thorpe is the author of:

• Best Practices and Case Studies for Industrial Energy Efficiency Improvement (with Oung, K. and Fawkes, S. UNEP, 2016)
• A London Conversation: Business Briefing on Green Bonds (The Fifth Estate, 2015)
• The One Planet Life (Introduction: Jane Davidson. Routledge, 2015)
• Earthscan Expert Guide to Energy Management in Buildings (Earthscan, 2013)
• Earthscan Expert Guide to Energy Management in Industry (Earthscan, 2013)
• Earthscan Expert Guide to Solar Technology (Earthscan, 2011)
• Earthscan Expert Guide to Sustainable Home Refurbishment