The World Green Building Council (WorldGBC) has issued findings reporting that the number of organisations committed to net-zero energy buildings has doubled in one year. This is an incredible statistic and shows the combined global effort we are all making to combat climate change.
Creating a sustainable world involves creating buildings which are net-zero. In 2015, the United Nations set an Agenda for Sustainable Development for 2030, which included 17 Sustainable Development Goals (SDGs), one of which being climate action.
As a UN member state, The UK has taken urgent action to combat climate change through the significant objective of achieving net-zero carbon emissions by 2050. As part of this direction, the construction and building sector has been tasked with the aim of all new buildings to be net-zero carbon by 2030, and all existing ones by 2050.
The UK Green Building Council’s 2019 document delivered a framework for net zero carbon buildings and how construction businesses must measure, reduce and offset carbon emissions in the industry and reassess how buildings are designed and constructed.
A net-zero energy building is one which relies on renewable energy sources to produce as much energy as it uses over the period of a year. This means the building sources or provides as much energy as it consumes, equating to a net-zero carbon result.
We have developed this guide to net-zero buildings to help you develop an effective and attainable net-zero emissions approach and take a leading role in combatting climate change.
Why Are Net Zero Buildings Important?
Building and construction accounts for 39% of energy-related global greenhouse gas emissions. 28% of this is made up of operational emissions such as the energy used to heat, cool and light buildings.
The remaining 11% derives from embodied carbon emissions found in the material and construction processes across a building’s entire lifecycle. Moreover, traditional buildings are responsible for consuming upwards of 40% of fossil fuel energy.
Implementing measures to reduce the consumption of energy in the built environment is a critical path to generating carbon savings. Developing net-zero buildings reduces the annual volume of carbon emission being released into the environment, consistently helping reduce the impact on the earth’s atmosphere.
Finally, the reduced energy consumption means that the need to drill for more fossil fuels is diminished as renewable sources step in to replace them.
How to Create a Net Zero Building?
The first step for organisations towards creating net-zero buildings is to invest in renewable energy sources. This removes the carbon emissions generated from non-renewable energy sources but also can significantly decrease energy costs in the future from rising fossil fuel prices.
To integrate renewable energy, buildings must have access to an electrical grid on-site or nearby that stores energy from solar, wind and more. Organisations can experience ROI as soon as the energy storage is paid off.
In addition to using renewable energy, organisations should employ energy-efficient technologies such as LED lighting and efficient HVAC units to reduce the amount of energy that needs to be consumed.
The mission of creating net-zero buildings must be split into two key sections: the construction stage of a building project and the operational stage.
The Construction Stage
The carbon emissions produced and released from the construction of a new build includes the amount of carbon emissions yielded from the building’s products and the physical construction up to completion.
This includes the extraction of raw materials, manufacturing, transport, installation, waste, repair, refurbishment and end of life processing.
Significant ways architects and developers can achieve net zero carbon emissions in the construction stage starts with lowering the carbon emissions of the building products used, including their carbon footprint. This can be achieved by lowering the use of virgin materials and opting for recycled ones.
Reducing the use of energy needed for construction from fossil fuels also decreases the carbon emissions associated with the build. Incorporating the use of offsets or the net export of on-site renewable energy can also mean the building can benefit from reduced carbon consumption.
Thinking about long term impact, it is also important to increase the life-cycle of materials in order to avoid the need for replacements during the building’s life. Offsetting carbon emissions also can be done through reusing materials after the project is decommissioned.
If there is any possibility of sequestering carbon from the project, this is also a permanent way of offsetting carbon emissions.
The Operational Stage
Creating a net-zero carbon building in operation is a key challenge for the construction industry as it requires us to reassess the way buildings are designed, constructed, and run.
A net-zero building’s associated operational carbon emissions must be zero on an annual basis, or, even better, negative. This requires the building to be highly energy-efficient and powered through either on or off-site renewable energy sources, with any remaining carbon emissions being offset.
The operation of a building in the construction industry is classified as the operation of specific parts of a building or built asset such as the lighting, cooling, HVAC, etc. as well as its other facilities such as facilities, equipment, tools, machinery etc.
For buildings on the mission to achieving net-zero carbon, they will require outstanding levels of energy efficiency alongside zero-carbon electricity and heat supplies.
For a successful net-zero building to be designed and developed, both stages of the process (construction and operation) must be considered. This allows the project to keep energy efficiency in mind during construction, and therefore allow the operational phase to begin with lower carbon consumption to be generated through renewables or offset.
What Guidance is Available for Practices and Developers to Help Achieve Net Zero?
There are many frameworks and design approaches that architects can implement to help them achieve their sustainability goals for projects, including net zero. In this next section, we will cover key resources to refer to.
The UK Green Building Council Framework
The UK’s Green Building Council have been responsible for developing the UK’s net-zero carbon framework explaining how the industry will achieve net-zero carbon for new and existing buildings by 2050.
The framework provides guidance that means architects can challenge climate change with support and direction. The document provides goals for a building’s carbon emissions, the options for offsetting carbon, either on or off-site and how renewable energy usage comes into play.
The framework also discusses how the ‘whole life’ of a building and its generated emissions, including explorations of embodied carbon depending on whether the building is commercial, residential, or a portfolio of building developments.
Passivhaus is a design and construction approach for the construction of buildings with the key principle being to deliver high levels of comfort whilst using very little energy.
According to its website, the definition of Passivhaus is driven by air quality and comfort: “A Passivhaus is a building in which thermal comfort can be achieved solely by post-heating or post-cooling the fresh air flow required for a good indoor air quality, without the need for additional recirculation of air.” – Passivhaus Institut (PHI)
Built with meticulous attention to detail and rigorous design and construction principles, Passivhaus buildings provide high levels of comfort for the occupant whilst focusing on minimising energy usage for heating and cooling. This means altering the design of a building to focus on using very little energy.
For example, net emissions can be reduced by using heat pumps which, given the increasing de-carbonisation of the electricity grid, now result in significantly fewer emissions than a gas boiler equivalent.
Fundamentally, Passivhaus standard buildings should involve the following within their construction:
- High levels of insulation
- High-performance windows with insulated frames
- Airtight building fabric
- Thermal bridge free construction
- A mechanical ventilation system with highly efficient heat recovery
Assessments for Residential Buildings Aiming to Achieve Net Zero
Next, we will explore assessments you can implement to measure and accredit your sustainability goals, including net zero. These endorsements apply to residential buildings.
BREEAM In-Use (Building Research Establishment Environmental Assessment Method) is an assessment for building owners and occupiers to measure the environmental impact of their existing building. It can be used to benchmark and drive sustainable decisions for the improvement of the building’s operation.
BREEAM In-Use can help building decision-makers achieve net-zero carbon emissions by using the tool to measure the performance of the building. The tool uses an integrated energy approach which is world-leading in environmental assessments.
Home Quality Mark
The Home Quality Mark is an accreditation for building organisations to highlight the quality of their residential properties. It is an independent report, provided through experts on home quality and performance.
The Home Quality Mark reports on costs, health and wellbeing benefits, and environmental impact associated with a building, for buyers and renters. The Home Quality Mark attributes a home’s quality through a rating system, as well as a variety of indicators on individual aspects of quality and performance.
The Home Quality Mark can support the net-zero carbon buildings ambition for residential properties, through highlighting to the end customer the high quality of the build and the positive environmental impact the building has.
Assessments for Commercial Buildings Aiming to Achieve Net Zero
Next, we will explore assessments that apply to commercial buildings and their developers, helping towards the goal of achieving net-zero.
BREEAM NC (New Construction) is a sustainability assessment method that is used to plan new projects, infrastructure and buildings. It is a standard for new construction projects that can be achieved through meeting a set of criteria set by BREEAM.
The criteria assess the design, construction and the use of the building and how future-proofed the development is. This standard can be applied to all types of new construction including extensions to existing buildings.
From focussing on the process of new construction, from design to finished product, the assessment ensures all decisions agreed during the development of the building are carried out and meet the standard of the BREEAM assessment.
BREEAM NC can support net-zero carbon buildings ambitions on new developments through driving improvement in sustainable building approaches and technologies from start to finish of a project.
BREEAM Refurbishment and Fit Out (RFO) assessment is a standard for developers and building owners for projects that are refurbishments.
The criteria covers the sustainability impact of the development including the design and construction and how it performs before and after the refurbishment works are carried out. The assessment covers the external building, the structure, the services and the interior design of the building.
If the project meets the standard of the BREEAM assessment, then it will be certified as a high-quality refurbishment or fit-out.
BREEAM Refurb can support net-zero carbon buildings ambitions on refurb projects through planning and measuring carbon emissions allowing building developers to achieve net-zero while simultaneously achieving better performance on all aspects of the design and development.
What Should Construction Professionals Do to Achieve Net Zero Carbon Buildings?
It’s highly advisable that you seek consultancy from sustainability professionals to help you achieve the best possible outcomes for your new build project.
At Sustain Quality we provide the following services:
You can learn more about each of these services by clicking on each link above.
We have also released two educational guides for anyone involved in the construction of a commercial or residential property.
Depending on where you are in the construction process, Sustain Quality can provide you with the necessary strategies to help your building achieve fewer carbon emissions.
At Sustain Quality, we champion an integrated design and engagement process. This will lead to improved operational performance and greater time and cost-efficiency. With our team of highly-skilled engineers, we can deliver sustainability and compliance solutions, helping organisations maximise the environmental, social and governance value of their building.
To learn more about our unique energy reduction strategies, read our case study that we recently completed for a Business Centre Warehouse Extension in North-West London.