Building envelopes

Tracking Clean Energy Progress

🕐 Last updated Wednesday, 23 May 2018

Not on track

Two-thirds of countries around the world lacked mandatory building energy codes in 2017, meaning that more than the current floor area in the US will be built using less efficient technologies over the coming decade. To meet the SDS target, the number of new high-efficiency buildings being built needs to increase from 75 million m2 today to more than 2 billion m2 by 2030. Deep energy renovation of existing stock also needs to more than double within the coming decade (with the current rate less than 1%).

Building energy codes and standards by country, 2017

Two out of three countries lacked mandatory building energy codes in 2017.

A wide range of building policy packages to improve building efficiency were introduced in 2016 and 2017, but those measures were not enough to keep up with rapid growth in global floor area.

A handful of countries introduced or updated building energy codes, and several countries implemented building energy certification or incentive programmes. For instance, China released a Standard for Energy Consumption of Buildings in December 2016 that includes prescriptive indicators of actual energy use for various types of buildings.

Nigeria launched its first building energy code in September 2017, and the 2007 Energy Conservation Building Code for commercial buildings in India was updated in 2017.

Progress on high-performance buildings construction, such as near-zero energy buildings (nZEBs), has picked up in a few countries, although it still represents a minor share of buildings construction.

France is a leader in the nZEB market, with a building code that requires all new construction to fall under its definition of an nZEB. In Austria, Belgium and Italy, more than 20% of residential new constructions in 2017 were nZEBs

On the renovation side, one notable development has been the expansion in 2017 of the Energiesprong programme, which is now present in four countries – France, Germany, the Netherlands and the United Kingdom. This innovative initiative seeks to achieve affordable zero-energy building retrofits.

Building energy certification efforts also picked up in several countries. Canada’s Green Building Council launched a dedicated Zero Carbon Building Standard in May 2017, making carbon emissions the key indicator for building performance. In Ghana, the Eco-Communities and Cities National Framework was launched in March 2017 to become an integral part of the National Housing Policy. Brazil’s Green Building Council also launched a Zero Energy Standard in 2017, and 11 pilot projects will evaluate the standard across five states.

Progress is being made on other fronts, such as the launch of the voluntary reporting framework levels initiated by the European Union in 2017.

A few countries are also working hard to deliver their first national building energy efficiency code, such as Mexico in collaboration with the International Code Council. Building energy codes upgrades also under way in South Africa include differentiation by climate zone.

Tracking progress

Building envelope performance improvement is not on track to meet the SDS. Building envelope improvements are critical to achieve the transition to sustainable buildings, but most countries have still not made them an explicit policy priority.

For instance, few countries mentioned specific projects or targets related to energy performance standards or efficient building envelopes in their Nationally Determined Contributions submitted as part of the Paris Agreement.

High-performance buildings such as nZEBs typically make up less than 5% of construction in most markets today, representing around 1% of global construction. Typical energy renovation rates are around 1% to 2% of the building stock per year, with average energy intensity improvements generally less than 15%.

Estimated global buildings construction to 2030

In order to meet SDS goals, high-performance envelopes need to become the construction standard

	Voluntary or without building energy code	Mandatory building energy code	nZEBs
2017	2853.275212	3524.27636	74.0571926
2025	630.068497	5152.670571	1218.02201
2030	338.5636455	4345.362224	2087.34704
"yAxis":{"min":0,"max":8000,"title":{"useHTML":true,"text":"million m2"}}

As of 2017, less than one-third of countries had a mandatory or voluntary building energy code, and only around 80 countries had building energy certifications, including 36 countries with mandatory building energy certification policies and another 20 countries with widespread voluntary building energy certification policies or programmes.

Building energy certification by country, 2017

Less than a third of countries had building energy certifications in 2017.

Building energy certifications also fall short of promoting major change in the buildings market, as they are typically voluntary or only cover a certain number of buildings.

In 2017 the International Organization for Standardization published its (ISO) 52000-1 standard for energy performance of buildings, which establishes a systematic and comprehensive structure for assessing building energy performance. But harmonisation is only one step towards the compulsory energy certification that is necessary.

Overall, the buildings sector continues to lag behind on envelope performance and is still far from meeting SDS ambitions.


The IEA’s new Innovation Tracking Framework identifies key long-term “technology innovation gaps” across the energy mix that need to be filled in order to meet long-term clean energy transition goals. Each innovation gap highlights where R&D investment and other efforts need improvement.

Explore the technology innovation gaps identified for building envelopes below:

Why is this RD&D challenge critical?

  • Good thermal insulation significantly contributes to energy conservation.
  • Applying insulation to already existing buildings is one of the most cost and energy efficient retrofitting measures.

Key RD&D focus areas over the next 5 years

  • New Super Insulating Materials (SIMS).
  • Includes Vacuum insulation panels (VIPS), Gas filled panels (GFP) and Aerogel Products (ABP).
  • Thermal conductivity of between 0.003 and 0.008 W/(m*K). Currently mainly used in fridges and other appliances.
  • Further development of less+ or non+invasive materials to address historical buildings that are hard to retrofit.
  • The materials are vulnerable so R&D focus should be on adaptation to be able and work with SIMS on construction sites.
  • Material costs also need to be further reduced.

Key initiatives

There are few initiatives for this. Manufacturers stick with conventional insulation materials. Six out of the ten largest companies producing insulation products are European.

Why is this RD&D challenge critical?

  • Thermal energy storage (TES) can lower the cooling and heating demand of the building.
  • Storage is a key component of a future low carbon electricity grid as it allows a high penetration from intermittent renewable energy sources.
  • Buildings (with storage) connected to the smart grid would help balance and improve the flexibility of the grid.

Key RD&D focus areas over the next 5 years

  • Three types of TES: Sensible, Latent and thermochemical.
  • Phase Change Materials (PCMs), a key type of latent thermal storage.
  • Reduce costs, increase compactness of the system, increase thermal conductivity of the materials, develop new materials with focus on fluids that can function as heat transfer and storage simultaneously.

Why is this RD&D challenge critical?

  • Integrating renewable technologies in the facade would decrease the net energy consumption of the building as this allows the building to generate energy.
  • Integration of renewables in the walls offer great potential as the related area usually is much larger than the roof area.

Key RD&D focus areas over the next 5 years

Further development and commercialization of Building Integrated Photovoltaics (BIPVs), Building Integrated Wind Turbines (BIWTs), Hybrid Solar-Wind, Adaptive Solar Façade, Solar roof tiles.

Key initiatives

Climate-KIC - ETH Zurich - ETH House of Natural Resources, Copenhagen International School (CIS), Tesla solar roof.

Why is this RD&D challenge critical?

Infiltration through the building envelope accounts for a significant share of a building's thermal losses. Other than raising the energy demand it causes mould and rot i.e. impacting the lifetime of the building.

Key RD&D focus areas over the next 5 years

  • Envelope Aerosol Sealing for new and retrofit of old buildings.
  • Further development of advanced foam and aerosol products such as a synthetic acryl sealant that can be sprayed or rolled on and automatically finds and seals cracks.
  • Refine sealing techniques.
  • Impact on ventilation, find optimal combination with mechanical ventilation.
  • Implementation of building regulations and codes.
  • Further advancement and reduced costs of thermal detectors.

Why is this RD&D challenge critical?

  • Windows are estimated to be responsible for between 5 and 10% of total energy consumed in OECD countries.
  • Highly insulated windows have great potential to reduce energy consumption in new buildings and in both installation and structural retrofits.
  • Maximizing/minimizing solar gains (depending on region) can significantly reduce heating/cooling demand especially for buildings with a lot of glass.
  • Optimizing Visible Light Transmittance (VLT) can reduce energy demand related to lighting.

Key RD&D focus areas over the next 5 years

  • Development of low-cost advanced materials with U values down to 0.6 W/m2K.
  • Improved manufacturing processes and identification of cost-effective installation techniques.
  • Focus has in recent years also been on vacuum glazing technologies to enhance thermal performance.
  • Dynamic glazing with variable Solar Heat Gain Coefficients (SHGCs) of between 0.08 and 0.65.
  • Further development of electrochromic windows.

Explore all 100+ innovation gaps across 38 key technologies and sectors here.