[Report] The GBPN Defines the Concept of Deep Renovation


The GBPN promotes a “deep” renovation of the existing building stock to help the building sector achieve significant global energy savings and plays its role in mitigating climate change. However, what does “deep” renovation mean? Do experts around the world use the same definition? This recent report “What is a Deep Renovation” seeks to harmonise and clarify a definition for deep renovation to help building a global knowledge dialogue and facilitate best practice sharing than can support better policy-making.

Minicover of DR Cover Report

The acronym “DR” can mean a deep renovation, a deep retrofit, a deep refurbishment, and to a lesser extent, a deep reduction. And these expressions mean different things to different analysts. A standard renovation or refurbishment will often achieve energy savings ranging between 20% and 30% and sometimes less. However, as the GBPN research shows with a “deep” renovation, it is possible to reduce a building’s energy use by more than 75%. Thus, there is a need to find a common understanding and developing as much as consensus as possible.
For this purpose, the GBPN gathered top global experts in the field of building renovation to reflect upon a common definition of DR through two webinars, a questionnaire and a review process.




Initially, the project collected current global and local definitions and conditions of a “deep” renovation (DR). These elements were then presented to thirty international experts in a webinar, during which participants tried to formulate a definition of a DR. These opinions and findings were later integrated into a questionnaire that was sent to the same group of experts, targeting a new level of harmonization and clarification.

What is a Deep Renovation?

Evidently, the reaction of the panel of expert underlined the absence of a common and pre-existing definition of DR. The definition of DR varies between regions.
According to this report, there is a clear and geographic distinction between the terms “deep renovation” and “deep retrofit”: European experts tend to use the expression renovation while American experts call them retrofits.

The report also shows that in Europe, “deep” renovation implies a minimum of 75% energy savings, whereas in the U.S. DR means improvements of 30%-50%. India and China, at this point, have no common definitions.

As outcome of the research, the GBPN and the experts that participated in the project are setting some commonly agreed definitions of deep renovation and retrofit.

The GBPN calls for further collaboration from different global and regional actors involved in deep renovation and is inviting them to participate in its knowledge platform through the “Laboratory” on “More and Deeper Renovation” to share knowledge and contribute their ideas. The GBPN is also working at the moment on further research on DR to develop criteria for selecting best practices for individual projects or groups of buildings that support the upscale of deep renovations globally.

What is a Deep Ronovation
Technical Report, GBPN, March 2013.

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