03/06/2019

With the Extinction Rebellion demonstrations recently hitting the headlines, and Sir David Attenborough warning us of the unsettling reality of the danger our planet is in, the UK Green Building Council (“UKGBC”) has published a new framework for the construction industry for achieving net zero carbon across the whole life of buildings.

The framework, published on 30 April 2019, was created by a collaboration of businesses, trade associations and non-profit organisations to provide guidance on the definition of net zero carbon buildings and to set a path that industry professionals can follow to achieve net zero carbon status. The framework sets out 2 definitions for net zero carbon:

  1. Net zero carbon – construction (i.e. emissions from the construction process): “When the amount of carbon emissions associated with a building’s product and construction stages up to practical completion is zero or negative, through the use of offsets or the net export of on-site renewable energy.”

Typical carbon emissions during the construction phase can include, for example, the transport of waste, the use of temporary offices on site and the inefficient use of construction plant (for example using oversized machines and high carbon fuels).

The framework encourages the industry to: 

  • Undertake a whole life carbon assessment at the start of the project to disclose to other parties, with the aim of parties agreeing reductions; and
  • Measure the carbon emissions and offset at practical completion. The construction company would approach a carbon offset provider, such as carbonfootprint.com, use the online tools to calculate the emissions of the construction process, and then pay the offset company to reduce emissions elsewhere in the world by the same amount. Examples of projects run by carbonfootprint.com include UK Tree Planting and Wind Based Power Generation. 

2. Net zero carbon – operational energy (i.e. in-use operational energy): “When the amount of carbon emissions associated with the building’s operational energy on an annual basis is zero or negative. A net zero carbon building is highly energy efficient and powered from on-site and/or off-site renewable energy sources, with any remaining carbon balance offset.”

This relates to how the building consumes energy once built. Practical measures encouraged by the framework include: 

  • Prioritising on-site renewable energy sources, such as solar panelling; and
  • Calculating in-use energy consumption, to be published annually.

There is clearly some way to go: published statistics showed that the amount of carbon dioxide emissions attributable to the construction industry in the UK increased from 8.8 million metric tons in 1990 to 12 million metric tons in 2016. In a typical residential block, 51% of total carbon emissions are created in the lead up to practical completion, 18% are due to the use of the building, 24% comes from operational emissions that are regulated under Part L of the Building Regulations (such as heating, cooling, ventilation and lighting) and 7% comes from unregulated operations emissions (such as appliance use and power plug loads). In an office building, a significantly higher proportion of total emissions is due to the use of the building (32%), whilst 35% is emitted in the lead up to practical completion, 18% is due to regulated operational emissions and 15% is due to unregulated operational emissions.

The framework recognises the challenge the industry faces and the UKGBC is encouraging building developers, designers, owners and occupiers to apply the framework and share any knowledge and lessons learnt. This will go towards a catalogue compiled by UKGBC displaying projects that either achieve net zero carbon for construction or operational energy or involve approaches which align with the framework.

Challenges of using the framework

Although the framework is a significant step in providing direction as to how to achieve net zero carbon buildings in both construction and operation, it is merely intended to act as guidance on the definition of net zero carbon emission buildings and demonstrating how a building has achieved this.

The question remains as to the extent to which the industry will be in a position to move towards reducing carbon emissions when the framework is purely voluntary. Although the Zero Carbon Policy was first announced in 2006 by the then Chancellor Gordon Brown, and intended for full implementation by 2016, it was dropped by the Treasury in July 2015 in a bid to boost housebuilding.

In an economically turbulent and price-competitive market for contractors, there is certainly an argument that it is counter-intuitive for builders to adopt a zero carbon approach if it is not mandatory when that approach may well drive up costs and reduce their chances of winning the work in the first place.

The apparent lack of commitment by the UK government to reduce carbon emissions does not promote confidence in the framework’s aim. After all, if the government does not make it mandatory to follow certain guidelines relating to net zero carbon emissions, then why should industry professionals bother following a framework that will probably only create more challenges for them during the construction life cycle?

It may be, however, that changing technologies will assist in bringing down the construction industry’s carbon footprint. Modular construction is increasingly seen as a way of addressing the UK housing crisis, with homes potentially built in only 10 days rather than the traditional 10 weeks. Whilst cost is primarily the driver for the anticipated increase in modular construction, a major benefit is a significant reduction in waste.  

In 2014, the Environmental Protection Agency reported that building projects created roughly 165 million tons of construction and demolition debris. However, as modular homes are built in factories according to specific measurements, the amount of waste material is drastically reduced. A 2007 report by the U.K. Waste & Resources Action Programme found that up to a 90% reduction in waste could be achieved by using modular construction. Once occupied, energy consumption is also typically less due to the use, for example, of solar panels, meaning bills are significantly cheaper.

It is evident from the publication of the framework and the growing use of modular construction that those involved in the construction industry are starting to take the need to reduce carbon emissions and use sustainable sources seriously. Tackling these issues is one of the biggest challenges being faced by the industry and its professionals. The framework agreement, whilst a welcome statement of intention, is only a first step in achieving net zero carbon buildings.