The purpose of this article is to explore what kind of (land-use) regulation is more compatible with a radical acceptance of the idea of the complexity of socio-spatial systems and of the intrinsic limits of explanation and prediction. The article applies insights from complexity sciences to planning practice, critically comparing different land-use regulatory instruments (in particular, patterning-instruments and framework-instruments). The main result and conclusion is that it is necessary to embrace the challenge of complexity and self-organisation, and consequently to start profound revision of regulatory instruments.

In the fields of planning theory and human geography, there is a growing discussion of the just city. The impression is that in order to continue the discussion of the crucial issue of the just city, certain methodological considerations and precautions are necessary. The article is focused on three in particular: (a) (urban) institutions as the first subject of justice, (b) the incomplete overlap between social justice and distributive justice, (c) the distinction between the concept and the conceptions of social justice. The impression is that these three issues are not always recognised, or at least not always to the fullest extent, in the current debate in planning theory.

In the course of the nineteenth century, many countries attempted to simplify their regulatory systems; since then, however, the entire legal apparatus has become ever more complex, being based on the (debatable) notion that law must mirror the growing complexity of society. Owing to this presumption, complex land-use and building issues have rapidly generated a host of equally intricate rules. However, some critics have argued that complex systems require exactly the opposite treatment, that is, simple rather than complex legal rules. This article explores the concept of simple rules for urban development, investigating what they are, why they are superior, and how they can be achieved.

In the early part of the twentieth century, planning theory and practice always voiced strong opposition to density. The error of this insistence was persuasively argued by Jane Jacobs in the 1960s. Subsequently, planning theory and practice came to recognise the importance of density, but this return to favour requires remaining constantly alert to the possible dangers and pitfalls. Critically considering the traditional and contemporary urban planning literature and the empirical evidence in the recent economic and geographical research, this article investigates the whys and wherefores of density in urban planning. It addresses two main questions: Is urban density really desirable (and why)? Is it effectively manageable (and how)? Density per se is meaningless unless it is a tool or condition for achieving something further. And even if the instrumental function of density were to be acknowledged, it is crucial to take into account that density is not solely (or merely) a tool which—in certain conditions—can be useful in reducing commute times and minimising the encroachment on undeveloped land. Its primary advantage concerns favouring the concentrated diverse admix of human preferences, tastes, abilities, know-how, uses, activities, and so forth. After having expressly laboured to avoid it for so long, the aim is not to create density directly, but to open the door and allow density to happen in our cities, thanks to more abstract and general planning rules.

Although a certain degree of consensus seems to pervade the ideas of “distributed energy systems” and “energy communities”, in truth, diverse views are involved. This article aims to shed light on the variety of interpretations of these two concepts. In particular, the article critically considers the answers to the following four questions: What exactly is meant by “distributed” in the expression “distributed energy generation”? Why is distributed generation (ethically) desirable? Why should people consider it a positive idea that “communities”—and not individuals or families—are invited to manage distributed generation systems? Lastly, can energy communities be considered different from standard state intervention and from market systems? Clearly defining these questions helps in emphasising crucial differences, and it is an important step toward achieving a critical understanding. The conclusion is that there is no single interpretation for either the idea of distributed energy or that of energy communities. Shifting emphasis from one feature to another can drastically affect what policies are required to foster the creation of such communities and of a distributed energy production scenario.