Credit 1.1-1.3- Building Reuse: Maintain 75%, 95% of Existing Walls, Floors & Roof, Building Reuse: Maintain 50% of Interior Non-Structural Elements
The defines the intent of MR1 as “extending the life cycle of existing building stock, conserve resources, retain cultural resources, reduce waste and reduce environmental impacts of new buildings as they relate to materials manufacturing and transport.” MR1.1 maintains 75% of existing walls, floors and roof while MR1.2 maintains 95%. When reusing the existing building structure, certain features must be removed from calculations. Windows, doors, non-structural roofing materials, and mechanical/electrical/plumbing equipment must be excluded. It is also important to note that if the addition to the existing building is more than 2 times the original, the credit cannot be achieved.
To receive points for MR1.3 you must maintain 50% of interior non-structural elements. Doors, floor coverings, interior walls, and ceiling systems are all applicable for this credit.
(Source: -NC 2. 2 Reference Guide)