Understanding low carbon and net zero construction

What is a Standard Low Carbon and Net Zero Building?

The UK government has set an ambitious target to achieve net-zero carbon in housing by 2050. This commitment involves transforming the way homes are built, renovated, and powered in a way that can significantly reduce the carbon footprint of housing stock. Through innovative policies and technologies, the goal is to create sustainable homes that contribute to the country’s broader climate change efforts. This means more energy-efficient buildings with renewable energies such as solar panel installations that help to reduce a property’s carbon footprint.

While low carbon and net zero carbon buildings represent the pinnacle of sustainable construction, they are designed to minimise and ultimately eliminate carbon emissions throughout their lifecycle. The measurable concepts of low carbon and net zero in sustainable construction, although interchangeable, have two distinct meanings. Carbon neutrality is achieved by reducing emissions to zero, while net zero is achieved by reducing emissions as much as possible and offsetting the remaining emissions.

However, the Net Zero Carbon Buildings Standard provides a comprehensive framework for achieving net zero carbon buildings and outlines clear criteria for energy efficiency, renewable energy use, and carbon neutrality. The Standard also helps the housing sector to show when any buildings have reached net zero carbon and are in line with the UK’s climate targets. The key principles of net zero carbon buildings include:

• Dramatically reducing energy consumption
• Maximising on-site renewable energy generation
• Offsetting any remaining carbon emissions
• Implementing rigorous performance monitoring and verification

What is Zero Carbon Construction?

Zero carbon construction represents a comprehensive approach to creating buildings that have minimal carbon impact. At the planning stages, architects and builders will work together to conduct detailed carbon impact assessments and set clear carbon reduction targets. This is done by engaging with sustainability consultants, manufacturers, and suppliers. To help achieve net zero carbon construction, the material selection on a project is important and architects and builders will work together to plan, design, and build a sustainable property.

Zero carbon property development represents a comprehensive approach to creating buildings that have minimal carbon impact throughout every developmental phase of a building’s construction. At the earliest stages of sustainable building, architects, designers, and builders will prioritise their low-carbon selection of eco-friendly methods and materials, using carbon-negative materials or those with transparent carbon footprints. In turn, they might install on-site renewable energy systems to maximise energy storage and create grid-interactive designs across the building.

How to Achieve a Net Zero Construction?

Net zero construction goes beyond traditional building practices, integrating sustainability at every stage of a building project, from the concept and feasibility stage, and through the entire design phase. At the earliest approach, achieving net zero construction will encompass creating passive design strategies that minimise the demand for energy usage across the home.

Key passive design strategies are known as ‘Passivhaus Design’ that architects, designers and builders will use to minimise energy demand across all types of properties. Passive Design Strategies include optimising solar orientation by positioning main living spaces and windows at south-facing elevations to maximise how much natural heat the areas absorb from the sun. Designs can have strategic window sizes that will help to capture even more solar heat during the coldest months of the year and with deeper window reveals to prevent overheating in the summer.

What is the Net Zero Fabric of a Building?

Thermal envelope design or its ‘building envelope’ are all the components of a home that separate the home’s interior from the exterior. To create a net zero carbon building that is in line with the Government’s decarbonisation standards, the fabric of a property should be well insulated to prevent heat being lost through air leakages and poor ventilation.

Known as a ‘fabric first approach’ to net-zero construction, this will involve retrofitting or planning improvements to a building’s energy performance through modifications to its physical fabric, rather than just relying on advanced technologies and renewable energy systems. This fabric first approach focuses on minimising energy demand by enhancing a building’s envelope and employing passive design strategies, such as:

• Optimising Insulation: enhancing insulation in walls, roofs, and floors. High-quality insulation materials and techniques are used to prevent heat loss during winters and heat gain during summers.
• Reducing Thermal Bridging: Thermal bridging occurs when heat easily escapes through areas with poor insulation, such as gaps around windows and doors.
• Air-Tightness: Preventing unwanted air leakage is crucial for energy efficiency. By sealing gaps, cracks, and joints, the building’s air-tightness is improved, reducing the need for excessive heating or cooling.
• Balanced Ventilation: While ensuring air-tightness, having a balanced ventilation system can help to maintain indoor air quality without compromising energy efficiency.

Therefore, as well as maintaining a building during winter to prevent heat loss through cracks or poorly-insulated spaces, architects can plan to optimise energy efficiency early on in the feasibility and concept stages. Enhanced insulation in a low carbon and net zero construction means prioritising insulation in the walls, the roof, and the floors of a property. It might also mean opting for high-performance triple-glazed windows and airtight construction techniques, such as building with concrete or stone to regulate temperatures.

Landscaping in the Net Zero Housing Sector

Achieving a net-zero building involves boosting natural ventilation to regulate temperature inside a property and, according to a recent Landscape and Carbon Report, more collaboration, education, and solutions are being put in place to achieve carbon-neutral buildings via intelligent landscaping schemes. In net zero construction, architects, designers, and builders use landscaping to boost natural insulation. For example, trees in a building’s natural setting can be harnessed for natural shading while biochar treatments can maximise carbon sequestration.

Plants and hedges can also be planted to create natural windbreaks to reduce heat loss while other designers will consider different landscaping options in external spaces that support the thermal regulation, such as green roofs, living walls, and vertical gardens which all absorb more CO2. Alongside biophilic designs that merge outdoor/living spaces in homes, these natural strategies can be integrated alongside a building’s renewable energy features to achieve a more carbon-neutral building.

What is Embodied Carbon in Construction?

Embodied carbon represents the total carbon emissions associated with a building’s materials and construction process. Reports suggest that embodied carbon from the construction or refurbishment of buildings makes up 20% of the UK’s built environment emissions. Unlike operational carbon, which occurs during a building’s use, embodied carbon is ‘locked in’ from the moment of construction, and sources of embodied carbon in construction may come from:

• Raw material extraction
• Manufacturing of building components
• Transportation of materials
• Construction processes
• Demolition and waste disposal

However, understanding what constitutes sustainable architecture and the construction strategies that can reduce embodied carbon construction are key. This means using low-carbon and recycled materials as well as opting for building products that are used in carbon neutral construction and accredited with environmental product declarations (EPDs).

Architects, developers, and homeowners can embrace the net zero carbon approach to combat climate change and create sustainable and resilient properties. By understanding and implementing low carbon strategies, it’s possible to reduce the environmental impact of your home and create healthier, efficient spaces for generations to come.

With the demand for greener homes never higher, sustainable architecture is what we specialise in and are passionate about. To speak to WindsorPatania about your own project, contact us today.