Thermal imaging of the building fabric in the net zero world

[edit] Introduction

The Sixth Carbon Budget, published by the Committee for Climate Change in 2019, requires that we need to reduce greenhouse gas emissions from buildings quickly and efficiently if we are to attain the necessary targets stipulated by the Government.

Buildings, and the built environment in general, use a significant amount of energy to provide heat to occupants. Therefore, reducing energy demand in the built environment means that we must take action to reduce the amount of heat necessary for the building to function while also maintaining acceptable levels of thermal comfort.

One function of the building fabric is to retain this heat. Verification of the thermal performance of the building fabric is a crucial element to reducing energy wastage in buildings

[edit] Surveying new and existing building stock

Thermal imaging of existing buildings can identify where new insulation needs to be installed. It can also show sources of major air leakage and thermal bridges. These areas are locations in the building fabric where relatively cheap and minor remedial work can create major improvements to thermal performance.

Thermal imaging is often used alongside air tightness and U-value testing to gather information about the need for new insulation in existing buildings. Measuring the energy loss from a building allows a designer, with existing knowledge about the designed energy demand, to do things like size a boiler or heat pump. The results are effective, and if performed multiple times throughout a retrofit project, can be used as a visual representation to show the real effects of the increased thermal performance as new elements are installed.

New buildings can be surveyed to ensure that the as-built construction meets the designed specification. Assessment methods (such as BREEAM) necessitate a thermal imaging survey to award the relevant classification. Information from thermal imaging reports allows designers and architects to modify designs and installations to improve overall thermal performance. This saves time, money and (most importantly for the net zero aspect) energy.

Thermography is a powerful tool used to verify and improve construction techniques in a bid to reduce the energy losses associated with buildings. It can also help to improve the thermal comfort of the occupants, following a ‘fabric first' approach.

With most buildings around in 2050 - the year the Government has set to achieve net zero energy targets - having been built already, we must give special focus to the technology and tools that will aid improvements to thermal performance in existing buildings. Thermal imaging is such a technology.

This article originally appeared on the BSRIA website. It was written by Joe Mazzon, Level 2 Thermographer, Building Performance Engineer and published in July 2021.

--BSRIA

[edit] Related articles on Designing Buildings Wiki

• Air tightness in buildings.
• BREEAM Testing and inspecting building fabric.
• BSRIA articles on Designing Buildings Wiki.
• Building fabric.
• Climate Change Act.
• Net zero carbon 2050.
• Thermal imaging to improve energy efficiency in building design.
• Thermographic survey of buildings.
• Thermography for traditional buildings.
• U-value.