Table 1.

The definition of “wicked problem” related to the provision of accessible housing.

Definition of Wicked Problem 1	Example from the Provision of Accessible Housing
1. There is no definitive formulation of a wicked problem.	The formulation of accessible housing is the problem. The information used to define the problem depends upon a variety of non-academic actors’ and institutions’ idea for solving it.
2. Wicked problems have no stopping rule.	What is considered a “good enough” provision of accessible housing is situational and continuously transforming.
3. Solutions to wicked problems are not true-or-false, but good-or-bad.	Solutions are likely to be differently judged, depending on the special value-sets and ideological predilections of actor and institution groups or their personal interests.
4. There is no immediate and no ultimate test of a solution to a wicked problem.	The full consequences of plans aimed at improving housing accessibility cannot be appraised until the waves of repercussions have completely run out.
5 Every solution to a wicked problem is a “one-shot operation”; because there is no opportunity to learn by trial-and-error, every attempt counts significantly.	Every action taken to improve housing accessibility is consequential for other household members, residents, or visitor. Major retrofit actions to improve housing accessibility affect the residents during the construction process, are expensive, and leave long-standing and irreversible traces.
6. Wicked problems do not have an enumerable (or an exhaustively describable) set of potential solutions, nor is there a well-described set of permissible operations that may be incorporated into the plan.	Many new ideas or efforts to provide accessible housing for the ageing population may become relevant as a resolution. For example, refined grant mechanisms for individual housing adaptations or assistive devices, supports for the housing sector, changes in building regulations or human right laws, or incentives for relocations. However, despite a set of possible candidates the problems could persist. Enlarging the set of solutions as well as choosing which solution to pursue and implement is a matter of judgement.
7. Every wicked problem is essentially unique.	The basis for decision-making related to the provision of accessible housing needs to be local, timely, and put into the context of available resources (e.g., technological, financial) and the specific real-world situation (e.g., social, cultural).
8. Every wicked problem can be considered to be a symptom of another problem.	The level at which problems are settled depend upon the various decision-makers. “Higher-level” problem formulations becomes broad and general, but less operationalizable. On the other hand, solely addressing the problems of providing accessible housing on a too low level and cure symptoms (e.g., individual housing adaptions, assistive devices) can create negative effects on several other variables and making it more difficult to deal with higher level problems.
9. The existence of a discrepancy representing a wicked problem can be explained in numerous ways. The choice of explanation determines the nature of the problem’s resolution.	Diverse worldviews and intentions (e.g., self-interest, profitability, cost-efficiency, health prevention, human rights) are strong determining factors for the various decision-makers. There are no optimal solutions or agreed upon ways to evaluate provision of accessible housing.
10. The planner has no right to be wrong.	Decision-makers become responsible for all the consequences of the actions taken to improve the provision of accessible housing. The increasing pluralism of the contemporary public, who use different and contradicting definitions and scales to assess and judge the consequences of the solutions increases the wickedness of the problem and related dilemmas.

¹ Rittel and Webber’s ten properties [15].