Design activities typically need a range of skills that requires a multi disciplinary approach.  Therefore a team of people with a manager or team leader/coordinator is required.  

Mono-disciplinary research questions or hypotheses can be successfully addressed by knowlegeable and skilful individual researchers. However, interdisciplinary, multi-disciplinary and trans-disciplinary research questions or hypotheses require collective research approaches. Although, collective research is often done in large scale international (such as EU and NSF funded) projects, there is no generic theory to explain multi-scale collaboration in a level- and context-independent manner. Current theories are not articulated enough with regard to various manifestations of collective research work. I differentiate between: (i) cooperation (involving information/knowledge/methods sharing and supporting organizational outcomes), (ii) coordination (harmonizing both explorative and confirmative research activities and instrumentations and support of mutual benefits), (iii) collaboration (giving up some degree of independence in research programs and efforts to realize a shared goal), and (iv) coadunation (achieving the state or condition of being united by gradual epistemological and methodological synergy forming and growth).

Formation of integration in collective research projects (from incidental partnership to strategic alliance) is a non-deterministic interest-driven process. Integration of collective research work is often emergent and volatile. As for the future, we need multiple theories to explain cognitive, behavioral, methodological, epistemological, procedural and praxiological issues and dependences.

The feasibility, significance, and relevance of your question depends on the context of the research project. Irrespective of whether or not a research is design by an individual or research team, the basic and most important issue is what is the objective of the research. It seems logical that a group of individuals (research team) may be better equipped given the context of the research prospectus to formulate and execute a cutting edge study design better than an individual researcher. This may not necessarily be true all the time. If the research implies the design, planning and execution ultilizing a diverse skillets, expertise and experiences than a team with the needed expertise and skills would be better situated to do the job. However, there are instances where you may have someone with all the relevant skills and expertise as the main architect of the research design. But having more brains a good than one. Again, it all depends on the funding agency, the research question, scope and the needed expertise.  

Thanks everybody for your answers. 

Generally speaking, by "design research", I mean:

https://en.wikipedia.org/wiki/Design_research

And in the case of my studies:

https://www.researchgate.net/publication/281906226_Integration_of_solar-climatic_vision_and_structural_design_in_architecture_of_tall_buildings

https://en.wikipedia.org/wiki/Design_research

Article Integration of solar-climatic vision and structural design i...

Dear Dr. Shahabian. Thank you for this clarification. Would you be kind enough to explain how your original question relates to the general overview of design research on Wikipedia and the nice research work presented in your paper? Thank you. Imre Horvath

How about supra-disciplinary research approaches?

Please consider: Supradisciplinary research practices: History, objectives and rationale, May 2004, Futures 36(4):407-421.

Design research usually afford many contributions and professional expertise.

I think collaborative design research is not only about affording or affordances. In certain cases, it is a must. If at least two non-overlapping disciplinary knowledge domains and research methodological resources (methodologies, methods, and means) should be involved in a research project, then it naturally calls for cooperative work. My very recent investigations cast light on the fact that, as we move from interdisciplinary research (IDR) through multidisciplinary research (MDR) to transdisciplinary and supradisciplinary research (TDR and SDR) there is a need to raise the knowledge, process, and method integration levels from low to high. More specifically it means:

IDR: typical form of co-working is cooperation that involves sharing knowledge/information and harmonizing (loosely orchestrating) research approaches

MDR: typical form of co-working is coordination that, besides the above, involves setting compatible research goals, harmonization of the research hypotheses, and specifying commons tasks in the exploration, (prototype) creation, and confirmation stages of research cycles

TDR: typical form of co-working is collaboration that, besides the above, includes a preliminary knowledge synthesis before the start of the project, combining research approaches, agreeing on collective purposes, and framing and operationalization of an integrated strategy (influencing both the research model and the research design)

SDR: typical form of co-working is coadunation that includes a comprehensive knowledge synthesis/fusion before the start of the project, a multifaceted knowledge consolidation at the end and, besides the above, interlacing research approaches on methods and techniques levels and complementing them with new dedicated ones, working in a unified reflection structure, and combining the research cultures.

These features can be recognized in funded applied and operative design research projects. Many call this trend as scientific or research convergence.