This paper explores the technical challenges and solutions in 3D concrete printing (3DCP), focusing on the relationship between the fresh and hardened properties of concrete materials and their impact on the geometry of printed objects. It classifies these issues based on construction applications to create a matrix of research and development challenges in this emerging field. The paper discusses key technical issues, including the properties of fresh materials, the challenges of achieving geometric conformity, and the factors influenced by application. It also highlights the importance of rheological properties, hardened material properties, and the ability to design structures that can be manufactured using printed materials. The paper provides a structured insight into the technical issues and solutions surrounding 3DCP, discussing the properties of wet materials used in 3DCP prior to solidification, the hardened properties of 3DCP materials, achieving geometric conformity, and factors affected by application. It also discusses the measurement of properties, the challenges of layer adhesion, bulk density and under-filling, tensile reinforcement, shrinkage and durability, and the measurement of hardened properties. The paper also addresses the issues of geometric conformity, including minimum feature size and tolerances, hatching and creating fully dense components, material and process modelling and simulation, and creating overhangs. The paper concludes with a vision statement describing the anticipated features and capabilities of design through manufacture using 3DCP processes in order to inspire creative thinking around the research issues. The paper identifies the interdependent factors affecting, and effected by, the component design and the mechanics and control of the process, and collates these issues to create a matrix of research and development issues that are dependent on the manufacturing application. This matrix is offered to bring insight and structure to help frame and direct future research and the developing discourse around the technology. The paper concludes with a vision statement describing the anticipated features and capabilities of design through manufacture using 3DCP processes in order to inspire creative thinking around the research issues.This paper explores the technical challenges and solutions in 3D concrete printing (3DCP), focusing on the relationship between the fresh and hardened properties of concrete materials and their impact on the geometry of printed objects. It classifies these issues based on construction applications to create a matrix of research and development challenges in this emerging field. The paper discusses key technical issues, including the properties of fresh materials, the challenges of achieving geometric conformity, and the factors influenced by application. It also highlights the importance of rheological properties, hardened material properties, and the ability to design structures that can be manufactured using printed materials. The paper provides a structured insight into the technical issues and solutions surrounding 3DCP, discussing the properties of wet materials used in 3DCP prior to solidification, the hardened properties of 3DCP materials, achieving geometric conformity, and factors affected by application. It also discusses the measurement of properties, the challenges of layer adhesion, bulk density and under-filling, tensile reinforcement, shrinkage and durability, and the measurement of hardened properties. The paper also addresses the issues of geometric conformity, including minimum feature size and tolerances, hatching and creating fully dense components, material and process modelling and simulation, and creating overhangs. The paper concludes with a vision statement describing the anticipated features and capabilities of design through manufacture using 3DCP processes in order to inspire creative thinking around the research issues. The paper identifies the interdependent factors affecting, and effected by, the component design and the mechanics and control of the process, and collates these issues to create a matrix of research and development issues that are dependent on the manufacturing application. This matrix is offered to bring insight and structure to help frame and direct future research and the developing discourse around the technology. The paper concludes with a vision statement describing the anticipated features and capabilities of design through manufacture using 3DCP processes in order to inspire creative thinking around the research issues.