In a pivotal announcement made last month, the Elmhurst Airtightness Scheme has clarified essential steps in the retrofit process concerning airtightness and background ventilation testing.

This guidance comes in response to recent discussions with Trustmark and aims to ensure that buildings adhere to stringent requirements for energy conservation and indoor air quality, two critical factors in the retrofit sector.

A critical aspect of the notice is the requirement that only lodged tests will be accepted as part of a retrofit project. By mandating that all tests be formally recorded and certified, it ensures that only trained and competent people are completing and providing data that forms part of important decision making. This offers stakeholders accountability, quality assurance and confidence in the testing process and resulting data.

Requirements of Airtightness Testing for Retrofit

Under the guidelines, all airtightness tests must be conducted by certified Level 1 or Level 2 testers who are registered with a Competent Person’s Scheme, such as The Elmhurst Airtightness Scheme- the fastest growing scheme for airtightness testers. This requirement ensures that only qualified professionals carry out airtightness tests, providing accurate measurements of a building’s air permeability at the time of testing.

These tests serve as a crucial tool for identifying leaks in the building fabric that can lead to energy loss, ultimately impacting building efficiency. Additionally, they help pinpoint buildings that may be excessively airtight, which can result in condensation issues and the accumulation of indoor pollutants.

The testing process must utilise appropriately calibrated equipment, adhering to the standards set forth in CIBSE TM23. The document outlines the necessary building preparation and testing procedures, ensuring consistency and accuracy in the testing process. Once the tests are completed, results must be lodged with the registered Competent Person’s Scheme, to produce a final certificate stating the air permeability of the building in cubic meters per hour per square meter (m³/h.m²). Only lodged air tests will be accepted as part of a retrofit project.

Requirements of Background Ventilation Testing

It has been clarified that background ventilation tests must be conducted by trained professionals who are registered with both a Competent Person’s Scheme, such as the Elmhurst Airtightness Scheme, as well as The Installation Assurance Authority’s (IAA) scheme for background ventilation testers. These professionals are required to adhere to the IAA’s Background Ventilation Assessment of Existing Buildings best practice guidance.

Background ventilation testing is essential for assessing the adequacy of ventilation within a building. This testing is particularly important in the context of energy efficiency upgrades, which can inadvertently reduce natural ventilation and impact indoor air quality. To ensure that buildings maintain a healthy environment, it is crucial that both pre and post-energy background ventilation tests are conducted and certified. This requirement has been emphasised in the recent posted notice.

The final certificate from these tests will indicate the air changes per hour (ACH), providing a clear measure of how effectively a building can exchange stale indoor air for fresh outdoor air at the time of testing. Only certificated tests will be accepted as part of a retrofit project. By following these guidelines stakeholders can ensure that retrofit projects not only enhance energy efficiency but also prioritise the health and comfort of occupants.

The Key Points:

• Only certified tests will be accepted for retrofit projects.
• All airtightness tests must be conducted by Level 1 or Level 2 airtightness testers who are registered with a Competent Person’s Scheme, such as Elmhurst.
• Background ventilation testers must be registered with both a Competent Person’s Scheme, such as Elmhurst, and the IAA’s background ventilation schemes.
• Both pre and post energy efficiency measure tests must be lodged to the registered Competent Person’s Scheme.

Final Thoughts:

As the retrofit industry continues to grow, adherence to these thorough requirements for airtightness and background ventilation testing is crucial for instilling confidence in the integrity of completed assessments. By ensuring that all tests are conducted by qualified professionals and that they follow established guidelines, stakeholders can trust that the results accurately reflect a building’s performance at the time of testing. This is a positive step towards achieving greater energy efficiency and improved indoor air quality.

If you would like to understand more about the difference between airtightness testing and background ventilation testing, please read our article: Air Permeability vs Background Ventilation – What’s the difference?