Last edited 26 Aug 2019

Main author

Tom Blois-Brooke Engineer Website

BREEAM Testing and inspecting building fabric

Contents

[edit] Background

The requirements for air tightness testing and thermographic surveys stem from criterion 4 of Approved Document L2A – Conservation of Fuel and Power in New Buildings other than Dwellings. Criterion 4 falls under Section 3 which looks at the Quality of Construction and Commissioning, a key element of which is the building fabric.

The Approved Document states the following with regards to building fabric performance:

3.2 The building fabric should be constructed to a reasonable quality so that:

Compliance with the above can be demonstrated as follows:

Continuity of Insulation:

Air Permeability and Pressure Testing:

BREEAM and Airtightness Testing / Thermographic Surveys

The requirements of this issue, as is common with BREEAM, go above and beyond the standard requirements to promote best practice through the industry through the use of airtightness testing (as set out in the Approved Document) and also thermographic surveys to quality-assure the integrity of the building fabric. This includes continuity of insulation, avoidance of thermal bridging and air leakage paths.

The credit also requires that the main contractor rectifies any defects identified in the thermographic survey prior to building handover.

[edit] Aim and benefits

BRE Report 176 (A Practical Guide to Infra-Red Thermography for Building Surveys) states that thermographic surveys can be used to demonstrate performance of a building and its components and services including:

  1. Insulation defect detection.
  2. Air leakage detection.
  3. Heat loss through window frames.
  4. Dampness detection.
  5. Examination of heating systems (e.g. damage to insulation).
  6. Preventative maintenance.
  7. Electrical defect detection.

Many of the above are not applicable to the BREEAM scope so the key benefits are stated below:

[edit] When to consider

[edit] Step-by-step guidance

There are two approaches that can be adopted for carrying out thermographic inspections:

  • Qualitative approach: a straightforward approach that can be used to identify items such as missing or defective insulation without the need for measurement detail. The images generated from this type of survey require interpretation by a skilled operator through examination of the thermographic images and the building structure.
  • Quantitative approach: a more detailed and stringent survey that requires analysis by a software package and produces a more comprehensive analysis of the building performance.

The operator will use their expertise to assess the survey data to identify any defective areas that require remediation based on the building construction methods and specified design criteria.

The BREEAM criteria are not prescriptive on the approach that should be adopted and advice should be sought from the project team on which is appropriate given the nature and complexity of the building being assessed. The wording of the criteria suggests that a qualitative assessment would be sufficient to meet the credit requirements but there are benefits in undertaking a quantitative approach for more complex buildings that may justify the increased expenditure. It should be noted that, having completed a qualitative level survey, if a decision is subsequently made to follow the quantitative approach it is likely that the surveys would need to be redone as the level of detail required is increased.

[edit] Tools and resources

[edit] Tips and best practice

[edit] Typical evidence

[edit] Applicable schemes

The guidelines collated in this ISD aim to support sustainable best practice in the topic described. This issue may apply in multiple BREEAM schemes covering different stages in the life of a building, different building types and different year versions. Some content may be generic but scheme nuances should also be taken into account. Refer to the comments below and related articles to this one to understand these nuances. See this document for further guidelines.

  • BREEAM UK New Construction: 2011, 2014 and 2018

BRE Global does not endorse any of the content posted and use of the content will not guarantee the meeting of certification criteria.

Authors:

--Tom Blois-Brooke 09:20, 04 Dec 2018 (BST)

[edit] Related articles on Designing Buildings Wiki