This thesis proposes a redesign of the OptimFlush water-saving toilet. The aim is to create a product that is attractive for the Dutch residential market, particularly for use in existing homes, while maintaining the water-saving functionality of the OptimFlush system. In light of increasing water scarcity, the goal is to reduce drinking water consumption.

The project starts with comprehensive research into the current product, the sanitary market, different stakeholders and sustainability. Several key insights emerged, the most important being that the toilet should be a wall-hung version. Consumers perceive this type of toilet as more hygienic and modern, and it also solves a common issue with floor-mounted toilets for installers related to mismatched drainage pipe heights.

Based on these findings, three design concepts were developed. The most promising concept involved integrating the OptimFlush system into the wall. This configuration provides greater design freedom and future-proofs the system, allowing other bowl designs to be connected later. The concept was validated through user testing, cleaning tests, FEA simulations and consultation with an installer.

The final design is a wall-mounted toilet with the OptimFlush system built into a frame behind a false wall. A distinctive wave pattern on the toilet lid makes the product recognisable, while the visible logo builds trust with installers.

The redesigned system features a modern and distinctive look that sets it apart from other toilets. The toilet achieves at least 50% water savings, benefiting both the environment and consumers, especially in times of rising water prices.

The thesis concludes with recommendations to communicate the benefits of the toilet to consumers, including potential water savings. It also advises on technical improvements, such as rotating the two outlet hoses to one side to prevent them from protruding from the frame.

The Packaging and Packaging Waste Regulation (PPWR) 2030 and the EU Circular Economy agenda are set to significantly impact businesses, particularly within the Fast-Moving Consumer Goods (FMCG) packaging sector. This thesis explores how businesses can proactively adapt by integrating recyclability into packaging design, improving stakeholder alignment, and navigating compliance challenges.

A market analysis highlighted the need to combine sustainability goals with technological innovation. The literature review identified key enablers for a sustainable transition, such as bridging knowledge gaps, dynamic capabilities, and stakeholder coordination, forming the basis of an initial framework.

To refine this framework, the research focused on three packaging case studies—examining both paper and plastic recycling. The analysis identified sortability in recycling streams and material contamination as key factors affecting recycled plastic quality (PCR). The primary recommendation is to design for mono-materials or ensure components can be mechanically separated during recycling.

Insights from 13 stakeholder interviews uncovered challenges, including actual recyclability, economic viability, uncertainty, and trade-offs. The study emphasised the importance of designing for multiple recycling infrastructures and streamlining packaging formats. Furthermore, it highlighted the need for stronger cross-stakeholder alignment to create win-win solutions and improve efficiency. A major barrier identified was regulatory uncertainty and technical verification under PPWR, complicating long-term strategic planning. Addressing this requires clear priorities and an urgent, structured approach within companies.

To address these challenges, this research delivers four key design solutions:
A tactical and strategic roadmap: providing a long-term vision for PPWR-compliant packaging, guiding companies from documenting recyclability cases to implementing an automated decision-support tool that anticipates regulatory changes.
A design process template: outlining key steps, evaluations, and complexity factors, ensuring structured decision-making and cross-stakeholder alignment.
An accompanying handbook: offering practical guidance on packaging design for recyclability, tailored to FMCG needs.
A proposal for a data-driven decision tool: enabling real-time assessment of packaging against recyclability criteria and upcoming regulations.

These solutions were co-developed and validated through sessions with packaging designers, marketing, and supply chain experts, as well as a validation session with R&D, ensuring practical feasibility.

This research contributes to academic literature by establishing a strategic framework for PPWR compliance and a structured design process for recyclable packaging. For practitioners, it provides an actionable pathway to prepare for 2030 and beyond, supporting the shift towards a circular economy and a more sustainable future.