The Asherverse consists of a series of constructs in which Asher spend his time or, more accurately, spends his mind and his being.
The Basis of Contructs
All space is constructed, apart from it being demonstrably 'real', because the boundaries of that space, it's operative use, and its relation to ourselves is constructed. Once we accept that all space is constructed, we can construe any coherent pattern of meaning that constitutes or symbolizes the locus of our thoughts at a given time as a construct of equal reality with any physical space. In this sense, there are no imaginary constructs, only inauthentic ones.
The Art of Building
A construct is a constructed space, person, cosmological reality, event, or other constructed reality. For example, any building is a construct.
Buildings are built on certain dimensions, defined by a certain architecture, and consist of certain rules, which are the basic mathematics of their existence.
Some constructs are merely physical places. Others are any combination of physical, temporal, virtual, intellectual, emotional, volitional, social, personal, consensual, mythic, literary, and artistic places.
Reality is Non-Local
The Arena, for instance, is obviously a virtual space, since it exists here on the web. It is also a social space, since it exists in certain social interactions, some of which are virtual and some of which are not. Written in a story or painting, it might also be an artistic space, involving an interaction between artist, art, and audience. It might, at the same time, if an actual building were purchased for it (e.g. The Office), be a physical space. It is, however, already physical in that you can find it physically on the web, or see it in physical interactions, or find it in physical art, or find it contained within a person.
Some Reality is Consensual
A construct is a consensual reality, requiring one or more persons to create or identify it. Constructs, then, are necessarily personal.
Constructs are given reality by their builders; they are created by the decision to build and treat them as real. They have the same kinds of impact upon persons as any other reality. They affect the mind, will, emotions, and body, just as the local coffee shop might. Constructs, then, are the intersection of what is commonly called reality and what is usually called perception. Again, they have the same kinds of effects (and usually some additional ones) on a person as anything else they take as real.