Whole-life carbon assessment

When talking about a building’s carbon emissions or carbon footprint, many people will be referring to the amount of carbon the building produces after its construction – in the form of fuel consumption, pollution and waste production. In terms of a circular economy, this is known as “operational carbon”.

However, there is another type of carbon emission that is often overlooked – “embodied carbon” (sometimes also referred to as “embodied energy”).

Operational carbon versus embodied carbon

Embodied carbon refers to the carbon footprint of the construction of the building, from the materials used to the impact of the processing, transport and energy consumption.

It also encompasses the maintenance of materials and should be accounted for in the “working life” of a building. The potential reuse, recycling and disposal methods of materials should also count towards embodied carbon as part of a building’s whole lifecycle.

Sustainable sourcing

Sourcing is one of the most crucial phases in a circular economy. Yet this initial phase has been largely neglected by targeted EU resource efficiency policies.

Worryingly, according to the World Wide Fund for Nature’s European Policy Office, Europe currently consumes the equivalent of 2.8 times more natural resources than is currently sustainable.

Utilising natural resources responsibly

Sustainable sourcing is about utilising our natural resources responsibly and with a view to the future. We can do this by:

• Ensuring resources are responsibly sourced, only using raw materials that are not endangered and can be replaced or regrown
• Reusing, recycling or repurposing already processed materials
• Supporting the businesses and communities taking care of these resources, by creating opportunities, fair trade and mutual benefit
• Utilising local materials to reduce transport use

Management and maintaining standards

The Wood Window Alliance (WWA) standards require members to be either FSC^® or PEFC^TM certified to ensure their windows and doors are made from wood sourced from sustainably managed forests.

Sustainable forest management also ensures more trees are planted than are chopped down, which in turn helps addresses deforestation, provides a protected habit for wildlife and creates a carbon sink.

Raw material processing

One of the most resource intensive and least eco-friendly stages of any production cycle is the processing of raw materials into usable parts and products. This often consumes a great deal of energy and resources and involves multiple processing stages, chemical additives and waste by-products.

Raw materials ideal for use as part of a circular economy production approach include those:

• Abundant in nature or can be regrown easily
• Requiring little processing
• Used to create multiple products
• Easily recovered, recycled or repurposed

Constructing truly green buildings

A truly green building is one that takes both embodied and operational carbon into consideration throughout the entire process – from initial design, through to the completion of the construction lifespan of the building in use. Unfortunately, few do.

Green building standards such as BREEAM, LEED v4, HQM and Ska help to assess operational carbon and are working towards including specific measures to regulate embodied carbon.

Barriers to building green

Perceived cost, lack of understanding, time constraints and a number of other barriers also stand in the way of creating truly green buildings.

However, more holistic schemes and regulations such as Cradle2Cradle and CEEQUAL v5 (a pilot project under BREEAM), as well as a greater understanding of whole-life carbon are working to change that.

The impact of nature

One global study found employee wellbeing was 15% higher in office spaces where greenery and sunlight were incorporated. The presence of natural elements also had a significant impact on the productivity of workers, with 36% feeling more productive.

What goes around, comes around

Every phase of a circular economy needs to be carefully planned and holistically designed to protect and enrich the framework of which it is a part.

From preserving natural resources to sustainable production practises and creating products that last well beyond their guaranteed lifespan – the circular economy is about taking what we already have and using it more wisely to build an economy that can regenerate itself over and over again.

A heritage of quality

Once only considered as part of a heritage planning requirement, wood windows and doors are increasingly being specified for their durability, performance and sustainability credentials.

Organisations like the Wood Window Alliance (WWA) are also helping to raise the standards and quality in the design and manufacture of both wood windows and doors – through independent verification and strict quality, performance and sustainability criteria.

Wood windows and doors are for life

Wood windows made to the Wood Window Alliance (WWA) standards have been shown to have negative Global Warming Potential over their estimated service life, according to independent research by Heriot Watt University.

Looking at wood casement windows made to WWA standards, they offer significant lifetime cost savings and longevity. The report found they had an expected average service life of 56 to 65 years depending on the level of exposure – double that of its PVCu equivalent, of between 26 to 35 years.

Carbon-negative wood windows

The findings of the report presents show that wood casement windows made to WWA standards offer significant lifetime cost savings and longevity of build for both the current and future building owner.

The report also asserted that each wood window frame made to WWA standards saved approximately 160kg CO² over its estimated lifecycle when compared to its PVCu equivalent, as well as being recyclable at the end of their useful life.