Systems & Envelope Performance Verification

Clock icon Created: December 15, 2021

Estidama PVRS Section IDP-R2:

In the Emirate of Abu Dhabi of the United Arab Emirates, there is a green building rating system called “Estidama”, which means “Sustainability” in Arabic. It is the initiative which has been transforming Abu Dhabi into a model of sustainable urbanization since 2010. Its aim is to create more sustainable communities, cities, and global enterprises and to balance the four pillars of Estidama: environmental, economic, cultural, and social.

Estidama sustainability guideline is divided into sections pertaining to different aspects of building requirements, one of these sections is our subject in this article, which is section IDP-R2: Systems & Envelope Performance Verification.

From our experience in the market, the people involved in construction of buildings and villas would always come across these requirements and ask the following questions:

  • How to comply with Estidama PVRS section IDP-R2: Systems & Envelope Performance Verification?
  • What is the pressure differential at which the allowable air leakage rate of 0.35ACH is given in credit RE-R1: Minimum Energy Performance?

To answer the first question, you will need to employ ATTMA-certified air leakage test engineers, such as Salimus team, who are trained, audited by ATTMA, and experienced in their field for more than 10 years, to plan and perform the test, and to troubleshoot the building in case it doesn’t meet the allowable air leakage requirements.

Regarding the second question, Estidama guideline does not mention the pressure differential at which the maximum allowable air leakage rate is given; therefore, we calculated it by comparing this leakage to the maximum allowable air leakage rate as per LEED Homes guideline, credit section EA: Air Infiltration, which awards 2 points (max) for projects located in IECC Climate Zone 1-2 if the building air barrier achieves 3.0 ACH at 50 Pa pressure differential across the envelope. Then by using air leakage formulas, we concluded that in order to make Estidama’s 0.35 ACH requirement as stringent as the best practice performance as per LEED guideline, the pressure for the 0.35 ACH shall be 1.8 Pa, considering that the power (n) of the air leakage formula is 0.65 based on our experience and on a study carried out in the US for a large sample of homes.

This highlights the importance of conducting residential investigations, carried by professional inspectors, such as Propetus team, of which air tightness tests, fog tests and infrared thermography tests are conducted; in order to ensure that there are no significant air leakages in the envelope, and to uncover any potential defects that negatively impact the energy performance of the building, such as missing insulation or thermal bridging.