Zero Carbon for Existing Buildings

06th January 2022
Zero Carbon for Existing Buildings

The world is currently in the middle of a climate crisis.

Countries around the world, including UK and Ireland are committing to Zero Carbon by 2050 or sooner. Construction developers and funders are understandably more focused than ever on Zero Carbon, as well as other ESG initiatives. The added pressure on developers and funders is due to fact that the energy used in buildings is responsible for 40-50% of annual carbon emissions (within the UK and Ireland.)

What is a Zero Carbon building?

A Zero Carbon (AKA Net Zero Carbon) building:

  • Does not use fossil fuels in operation
  • Has benchmarked low energy demand
  • Is 100% powered by renewable energy (generated on or off-site and with ‘offsetting’ as required)

Embodied carbon should also be considered, with priority given to reused and low carbon materials and following circular economy principles. When operational and embodied carbon are considered together, this is known as whole life carbon.

NZEB for existing buildings graphic4 NZEB for existing buildings graphic3

How to Achieve Zero Carbon

IN2 are highly experienced in developing and delivering low energy, low carbon buildings for the last 20 years.

IN2 follow and develop an industry recognized best practice approach to achieving and future proofing for Zero Carbon in operation for both new and existing buildings. Whether new or existing, our designs will seek to follow an energy strategy to reduce demand and consumption.

At IN2 we recognise each project requires a bespoke assessment to determine the optimum solution. This is because every project has its own unique set of characteristics and site-specific challenges (massing, orientation, form factor, construction type, use type, operational hours to name but a few).

NZEB for existing buildings graphic2

How does this work for Existing Buildings?

There are several tasks IN2 can execute to determine the optimum solution for Zero Carbon for an existing building:

  • Assess existing energy requirements and billing information
  • Assess existing as built information
  • Survey to validate existing information and servicing strategy
  • Develop an energy profile using dynamic thermal modelling software for the existing development
  • Calibrate the dynamic thermal model to accurately match the billing data, where possible and as required
  • Develop the best practice energy strategy principles that the development should follow / aim for, including benchmark energy targets
  • Test and report on a range of servicing strategy options (e.g. natural ventilation vs. MVHR)
  • Test and report on a range of fabric upgrade measures (e.g. cavity fill vs. external insulation)
  • Review options for centralized energy where applicable
  • Ultimately, report on the combined energy and cost savings for the optimised solution to get to Zero Carbon in operation

Best practice retrofit strategies will typically encourage a ‘deep retrofit’. Shallow retrofits should generally be avoided due to number disadvantages associated with suboptimal upgrade works. See image below on the example differences between deep retrofit vs. shallow retrofit.

NZEB for existing buildings graphic

Building User Benefits of Zero Carbon Retrofits

  • Healthy: Best practice retrofit can reduce NO emissions from buildings and improve internal air quality by filtering incoming air and tackling damp.
  • Resilient: Retrofit is an opportunity to mitigate flood risk to our homes, address overheating and become more resilient to storms and extreme cold weather.
  • Protecting Assets: Best practice retrofit can protect our heritage and improve building capital.
  • Comfortable: Best practice retrofit can make warm homes more affordable, whilst addressing the risk of overheating. Best practice retrofit can reduce noise ingress to healthy levels.

Financial Benefits of Zero Carbon Retrofits

  • Societal
  • Less fuel poverty because energy bills are lower.
  • Lower health-care costs because occupants live in healthier buildings with good air quality and thermal comfort.
  • Lower energy generation & infrastructure costs because energy demand and peak loads have been reduced.
  • More local jobs as retrofit is a labour intensive activity benefiting local economy.

Individual and Business

  • Lower energy bills if buildings are substantially more energy efficient
  • Reduced maintenance costs
  • Higher asset value because buildings are more energy efficient, comfortable & durable
  • Improved productivity as occupants live in healthier & more comfortable budlings
  • Reduced rent & void periods as tenants enjoy lower bills and pleasant buildings
  • Lower costs relating to carbon such as, offsetting, carbon taxes and carbon capture because energy demand and peaks loads have been reduced.

Want IN2 on your next project? Get in touch below.