COP26 For the Future of the Built Environment
10th Nov, 2021
Dominating every news outlet across the world, COP26 is throwing all sorts of possibilities into the public domain – and rightly so. Leaders across over 200 countries are thinking, talking, and listening to environmental issues which need to be acted upon. In an industry where we are quite literally building the future, our scope of work is on the edge of change.
At government level, the points raised in Glasgow demand a binding legal framework to accelerate action against carbon emissions. This includes the protection of communities and natural habitats. These are just grassroots of transformation in a neglected field needing immediate attention – or we face a future of scorched and flooded horizons.
For the construction industry, there are two key goals to take away from the conference. Carbon emissions should be reduced to Net Zero by 2050 and global mean temperature rise needs to be limited to 1.5°C above pre-industrial revolution levels. Essentially, it’s cause and effect. After the highest ever emissions from the UK construction industry in 2019, the International Energy Authority estimates direct building CO2 emissions need to fall by 50% by 2030, equating to 6% per year.
Carbon negativity can help; and is something to aspire to. SDS is already carbon neutral by offsetting remaining carbon emissions and adopting a green travel policy. We will continue to protect and conserve our communities by maintaining our active involvement in litter picking, beach cleaning, and volunteering.
With our industry responsible for around 40% of CO2 emissions every year, there are several opportunities for decarbonisation:
· Reduction of primary energy use of new and existing buildings
· Associated reduction of CO2 emissions by systems
· Improvement of new or existing construction fabric and junction thermal efficiency
· Addition of zero carbon technologies
· Reduction in air permeability of new or existing building services systems
New Building Strategies
The ethos of sustainability and a fabric first approach is vital in meeting construction-related targets. Fabric first means integrating thermal insulation, natural ventilation, and air-tightness into a building’s design. Instead of installing energy-saving technology like solar panels after it’s built, fabric first future-proofs performance and durability.
To improve, several existing standards will require special consideration:
Overheating risks
Domestic new build properties are far less leaky than existing buildings. Designs must determine how big the risk of overheating is during the summer using factors like window-openings.
Indoor air quality
Our challenge is to make sure less permeable buildings are healthy by diluting air pollutants to mitigate the risk of Building Syndrome.
Airborne infection
Now more than ever, managing air change rates so they are acceptable should be a key consideration to minimise the risk of coronavirus transmission.
Existing Building Strategies
Because 80% of the buildings which will be around in 2050 have already been built, there is a huge benefit of working to improve existing building stock. It is far more efficient to enhance buildings rather than expend energy and embedded carbon emissions to develop new ones.
Despite government policies surrounding existing properties taking a back seat, we need to drive work in this direction. Every solution is bespoke to the project but things to consider are:
· Thermal fabric efficiency and air permeability improvements
· Retro-fit ASHP, or blended boiler replacement, leading onto;
· Hydrogen use
Refurbishments can reduce the carbon impact in the ongoing operation of the building; improving building fabric and infiltration minimises heat lost.
The integration of renewable technologies is a consideration with photovoltaic arrays, battery storage, and solar thermal.
Older lighting points can also be inefficient, poorly controlled and unhospitable. By reviewing lighting installations and methods of control, energy use can be cut significantly.
Most existing properties utilise traditional gas boilers. However, an air source heat pump (ASHP) uses latent heat from air outside to increase temperature, using a liquid refrigerant. The government is keen to implement ASHPs – promising 600,000 installations per year by 2028. However, these pumps need to be part of a package of measures due to their difference in output. Unless the thermal efficiency of the building fabric is improved, chances are you will need a larger radiator to meet the same temperatures.
A new contender in the energy source market is green hydrogen. Blending this at 20% with traditional gas will initiate gradual decarbonisation of the National Grid. Using infrastructure already in buildings utilises embodied carbon and alleviate the need for replacement, as well as lessening demand for ASHPs.
Keep updated on COP26 here.
