Sustainability has been defined with different perceptions and from diverse dimensions making it an ambiguous concept to objectively engineer and integrate into software development lifecycle. Although a large body of knowledge already exists on what sustainability is and isn’t, little research has explored how to quantify sustainability. How can the definitions and perceptions of sustainability from software engineering and other fields be turned into requirements, effective measures that quantify sustainability and most importantly can inform a “sustainability by design” approach? What are the measures and measurement scale of sustainability? Our long-term research goal is to answer such questions and similar ones. In this position paper, we summarize our investigations and pave the road for a theoretical ground of sustainability quantification in software development and measurement. The goal is to foster research and standardization initiatives on sustainability as a quality attribute and sustainability by design.