UK Building Stock Carbon Reduction Commitments

Keeran Jugdoyal
How much CO2 is emitted by the buildings in which you live and work? How about the buildings you develop, refurbish or operate?

Emissions from the UK’s 25 million dwellings and two million commercial and public buildings account for 17% of the country’s direct Green House Gas (GHG) emissions . These emissions are primarily due to fossil fuel use in space heating, but indirectly, buildings also account for two-thirds of the power sector’s emissions, mainly due to electricity demand from lighting and appliances.

Buildings have a crucial role to play in achieving the UK’s carbon targets and therefore contributing to the country’s pledge to the COP 21 global climate change agreement. The agreement is a legally-binding carbon reduction plan aiming to limit global warming to 1.5 oC, measured in relation to pre-industrial levels.

The Global Scene - How Does The UK Compare With Other Countries And Members Of The EU?

Looking at CO2 levels at a global level, the UK, as part of the EU, is currently amongst the three regions with the highest impact. Based on 2015 data , China was the single highest emitter, being responsible for circa 30% of total global emissions, with the US (15%) and the EU (10%) following suit.

Taking a closer look at CO2 emissions per inhabitant (2012 Eurostat data ), the UK ranked 16th amongst the 28 EU member countries, with 7.6 tonnes of CO2/ inhabitant, approximately 3% higher than the EU average and 2.6 times greater than the CO2 /inhabitant being emitted from developing countries (see Fig 1).

Fig 1

Source: Data from Eurostat (2012 data)

The UK Picture – What Is The UK Doing To Reduce Its Impact?

Through the Climate Change Act 2008, the UK has pledged to reduce CO2 emissions by at least 80% (in relation to 1990 levels) by 2050, thus contributing to global emissions reduction targets aiming to limit global warming. The implementation plan includes five-yearly carbon targets from 2008 until 2032, which restrict the amount of GHG the UK can legally emit in a five-year period.

In the latest data (2015), UK carbon emissions were 1,569 MtCO2e, with a 15% decrease recorded in the buildings sector (in 2014) due to reduced heating demand from warmer winters (climate change impact). According to the Committee on Climate Change (CCC) , this figure and the current CO2 emissions reduction rate, provide confidence that the UK is on track to meet and outperform (i.e. achieve greater reduction in CO2 to what was targeted) its short-term carbon budgets, i.e. the second period (2013 – 2017) and third period (2018 – 2022). However, to meet its long-term aspirational reduction targets, the UK will need to increase the annual rate at which CO2 emissions are being reduced by at least 3%, starting now. For the property sector, this could be translated into an acceleration of net zero carbon new buildings and refurbishments.

The UK Picture – Impact Of Policy Regulatory Framework

Several policies have attempted to reduce UK buildings-related CO 2 emissions. These policies range from corporate taxation directly linked to CO 2 emission generation for large organisations, to incentives to utilise low/zero carbon energy sources for heat/electricity, and implementation of minimum energy efficiency performance standards.

The latest UK direct building emissions trajectory to 2032 (see Fig 2) illustrates an improvement (in relation to the previous trajectory) in the residential sector, which could be an indicator of success for policies and initiatives around increased fabric performance, as well as wider deployment of energy efficient appliances and lighting.

In its latest progress report   presented to UK parliament, the CCC assesses the impact of all policies in relation to projected CO2 savings.  As an example, policies such as the Renewable Heat Incentive (RHI) and the Carbon Emissions Reduction Target (CERT) for energy companies, have performed well. Others have fared less well, with Part L of the Building Regulations, for example, undermined by the performance gap between design and post-construction CO 2 emissions.

Fig 2

Source: The Committee on Climate Change, Meeting Carbon Budgets – 2016 Progress Report to Parliament

Overcoming Challenges – The Importance Of Refurbishing The Existing Building Stock

Whilst great progress has been made in reducing the carbon footprint of new buildings, this is somewhat offset by the low retrofit and replacement rates (approximately 0.5% for domestic and 1% for non-domestic buildings per year) of the existing building stock . As 75 - 85% of the current UK building stock will still be in use by 2050, there is significant need for effective policy which will overcome the below technological, behavioural and managerial barriers  associated with low carbon and deep (i.e. net zero energy/carbon) retrofit:

  • Managerial – lack of initiatives to incentivise energy neutral refurbishments;
  • Behavioural– familiarising users with carbon reducing technologies and training them to use buildings in a CO2 responsible way;
  • Technological – minimising disruption to existing users and to the existing façade and introducing the right mix of intervention measures and low carbon technologies for the diverse nature of the existing building stock

Overcoming Challenges – Accuracy In Building Carbon Footprint Prediction At Design Stage

The property industry acknowledges the need for bridging the performance gap between actual metered energy consumption and figures predicted during the design stage. Recent research from the Carbon Trust  demonstrates that in-use energy consumption can be five times higher than what was estimated in the Building Regulations UK part L (BRUKL) output document (prediction of energy by end use and carbon footprint) produced at design stage.

The performance gap is a combination of poor assumptions when predicting energy consumption and carbon footprint at design stage (e.g. exclusion of unregulated loads, standardised assumptions for occupancy hours and controls), followed by a lack of monitoring post-occupation. In other words, current predictions tend to be unrealistically low whilst actual energy demand is typically unnecessarily high — but this is rarely flagged up due to lack of monitoring).

There is therefore work to be done in more realistically representing a building’s carbon footprint at design stage, aligned with a regulatory framework which will increase visibility and monitoring of operational performance.

Overcoming Challenges – Changes In The Political Landscape - Brexit

Brexit could imply a change to the cost-effective path to the UK’s 2050 target, with the long-term consequences dependent on the shape of the final relationship agreed with the EU. The potential negative shock to the economy over the medium and long-term, predicted by the Institute for Fiscal Studies and the Bank of England, could imply less energy use and a lower level of emissions, and a consequently lower carbon budget.

Besides GDP impacts, there could be changes in the structure of the economy, depending on the nature of trade deals that the UK secures, population projections could change with different migration rules, and interest rates and exchange rates could be affected. All these could affect the level of energy demand, manufacturing and agricultural production and the cost of both high-carbon and low-carbon options.

What Can The Property Industry Do?

The property industry has a vital role to play in helping the UK government meet its CO2 emissions targets. The good news is that the sector is rife with opportunities for both adaptation and mitigation, and there is great added value (higher asset value, future proofing against climate change impacts, enhanced occupant health and wellbeing) in pursuing carbon reduction targets which go above and beyond current building regulations compliance.

Creating, assessing and accelerating opportunities for deep retrofit of existing buildings is at least as important as maintaining high performance standards for new buildings. To further increase efficiency and trigger greater behavioural change for both new and existing buildings, the industry should start moving from design standards to performance verification standards, and increase public reporting on buildings’ GHG, energy, and water use.


RICS Property Journal (July 2017 edition)