The Importance of Setting
Settings are very important in works of drama, and playwrights choose them carefully. Tennessee Williams chose a run-down building in New Orleans for his 1947 play, A Streetcar Named Desire, because The Big Easy is such a contrast to Blanche DuBois' genteel upbringing in Belle Reeve. Samuel Beckett set Waiting for Godot on a desolate country road near a tree because it helped emphasize the play's existential nature. Henrik Ibsen chose to set his 1879 play, A Doll's House, only in the Helmer household for specific reasons, as well.
By setting A Doll's House only in the "doll's house," Ibsen gives the audience a sense of Nora's reality. Her only concerns are her house and her family. The outside world, including its laws, is of no importance to her. Therefore, the audience is not shown the outside world, just the confinement and restrictions of Nora's world as represented by the house.
Also, setting the play only in the Helmer household keeps the play's focus on Nora. It wold be easy to get distracted by the subplot about Christine's and Krogstad's relationship or about Torvald's new job as bank manager. Ibsen, however, keeps scenes involving these aspects and not Nora off-stage. The audience is told what happens only through the dialogue between Nora and the other characters. The play remains about Nora because of this focus on her.
When Patrick Garland and Joseph Losey made their film versions of A Doll's House in 1973, they lost this focus. Instead of limiting the play to the house as Ibsen did, they showed all the action that occurred off-stage, and even invented some new action. The audience sees everything that happens, and that takes the focus off of Nora (Jane Fonda/Claire Bloom) and makes the films about everyone involved. The films are not about a woman's self-discovery but about how one woman's actions affect the others around her.
I do not think Ibsen would have liked the films for just that reason. By expanding the setting from the Helmer's house to the entire city, Garland and Losey destroy the message contained within A Doll's House. Even though setting can seem like such a small detail, it really is a crucial element in a drama and film.