New IEA web portal reveals gaps and solutions in buildings efficiency

The International Energy Agency (IEA) has created an important new web portal to make innovative technical and market information available to energy and construction professionals.

The IEA, perhaps better known as a tracker of energy trends, has, for decades, fostered cutting edge research of new and low carbon technologies through its Technology Collaboration Programmes. But the extremely valuable results were buried in obscure areas of its website and R&D communities.

Now, at last, the best of this has been brought into the light and made fully searchable.

The technologies covered are grouped under power, buildings, transport, industry and energy integration. The content reveals the IEA’s estimates of the market readiness of each one in terms of their ability to support the zero-carbon energy revolution.

In the category of buildings, only lighting and data centre networks are judged to be “on track”. Building envelopes and heating are “not on track”. Cooling, appliances and equipment are labelled “more efforts needed”.

In the industry and energy integration categories, no technologies are “on track”, and in transport and power, only electric vehicles and solar PV are.

For the IEA, there is a great deal of work to be done around the world to bring about the energy transformation, and it sees public innovation investment as absolutely vital in partnering with the private sector to make the transformation happen.

The problem of building envelopes

In looking at the problem of building envelopes you can see why – in the most recent survey, in 2017, two-thirds of the world’s countries had no mandatory building energy codes in place. This will lead to the equivalent of the current floor area of buildings in the United States being built in the coming decade with inefficient technologies. These are buildings that could stay functional for another fifty years.

There is some progress: China’s Standard for Energy Consumption of Buildings, published at the end of 2016, does include prescriptive indicators of actual energy use for various types of buildings. And Nigeria, which contains the world’s fastest growing city, Lagos, launched its first building energy code in September 2017.

The IEA believes that high performance envelopes must become the construction standard. But less than a third of countries had building energy certifications in 2017. In Australia, it’s only partially mandatory – with widespread voluntary certification – and in New Zealand it’s not at all mandatory for the performance of buildings to be certified.

Even where they are mandatory, all building energy certifications frequently fall short of promoting the major improvements in construction practice, and often only cover a certain type, or number, of buildings.

The International Organization for Standardization’s (ISO) 52000-1 standard for energy performance of buildings establishes a systematic and comprehensive structure for assessing building energy performance that all countries should follow.

Building technologies explored

And why not? It makes everyone winner. New technologies mean new jobs, reduced costs, and improved environments. The IEA’s portal dives deep into the most exciting new technologies at the cutting-edge of the potential transformation, where buildings could become zero or even negative carbon.

New super-insulating materials that reduce heat losses and gains and reduce thermal bridges, such as vacuum insulated panels, and gas-filled and Aerogel products, are lurking on the horizon and can have a thermal conductivity as low as 0.003W/m2K. They’re currently mainly used in refrigeration – but costs need to be brought down before they can be applied to buildings.

Also exciting is the prospect of integrated thermal storage in buildings, using sensible, latent and thermochemical storage media, such as phase change materials. This will help with the decarbonisation of heating buildings. The IEA sees thermal storage materials of the future including more fluids that can function as heat transfer and storage at the same time.

If they are coupled with renewable energy generation, this thermal storage could see these buildings linked to more building-integrated photovoltaics, wind turbines, hybrid solar-wind, adaptive solar façades and solar roof tiles. 

And what about spray-on draughtproofing? Because draughts contribute to a significant part of buildings’ thermal losses, it must be made easier to retrofit buildings to remove unwanted air infiltration than it is at the moment. The IEA highlights a key new technology, called Envelope Aerosol Sealing, which could help. This uses advanced foam and aerosol products, such as a synthetic acryl sealant, that can be sprayed or rolled on to building façades and automatically finds and seals cracks.

With five to ten per cent of total energy consumed in OECD countries leaving buildings through leaky windows, replacing old ones with highly insulated models could also seriously reduce energy consumption.

At the same time, using coatings on window glass can help to maximise or minimise solar gains (depending on the climate) to reduce heating/cooling demand, especially for buildings with a lot of glass. The simultaneous application of the technique of optimising visible light transmittance using glass coatings can also reduce the energy demand for lighting.

In practice this would translate to windows with U-values as low as 0.6 W/m2K (Energy Star recommends 0.25 W/m2K, so 0.6 is only a current average), cost-effective installation techniques, and dynamic glazing with variable Solar Heat Gain Coefficients (SHGC) of 0.08 to 0.65. Energy Star currently recommends, if air conditioning is not a concern, a high SHGC (0.35-0.60) to take advantage of winter solar heat gains. At the other end of the scale, and if no shading is available, it recommends a SHGC below 0.32. 0.08. 


Improving air-conditioning equipment performance is another vital area for action, to curb the growing energy demand for cooling. In Australia the efficiency of air conditioning lags behind many other countries with 3.5 being the average energy efficiency ratio, compared to 5.3 in Europe and 4.6 in Korea.

But there are exciting new developments here too, in a technology with the far-too-long name of “desiccant wheel assisted separate sensible and latent cooling system”. In simple language this means that because humidity, or rather the latent heat that it contains, is responsible for a large share of the cooling demand in many locations, a simple system that addresses this efficiently, and adjusts according to the season, is being developed.

Another technology, liquid desiccant cooling, could also help achieve higher air dehumidification, and can work well with solar-powered cooling, since it can operate at low temperatures.

A prototype “Climate Comfort Box” that would deliver high efficiencies with flexible storage for heating and cooling at affordable prices is being developed by the IEA’s Technology Collaboration Programmes for Heat Pumping Technologies and Energy Storage through Energy Conservation.


The share of heat pumps and solar thermal heating needs to triple to more than one-third of new heating equipment sales by 2030, the IEA say. It would be perfect for much of Australia. 

District heating is a promising technology too, but its carbon intensity needs to improve by using more low-carbon generation technologies, better management of heat demand (like heat meters and insulation) and greater flexibility (like allowing variable renewable energy to be used as heat, and excess heat from industry).

Germany, as part of its energy transition, is pioneering the use of deep and medium-deep geothermal energy, where in 2017, 24 deep geothermal plants in Germany produced around 895 GWh of heat for local and district heating systems.

In summing up the impact of all these innovations, Dr Fatih Birol, the IEA’s Executive Director, said. “These breakthroughs are helping drive down costs, increase efficiencies and boost deployment. But much more needs to be done… and in a wider variety of clean energy technologies.”

Meanwhile, the IEA is looking forward to 24 June 2019, when Dublin, Ireland, will be hosting the 4th Annual Global Conference on Energy Efficiency, where these and many more innovations, particularly in the area of financing, will be highlighted.

David Thorpe is the author of Passive Solar Architecture Pocket Reference, Energy Management in Buildings, and Sustainable Home Refurbishment

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