First cut out the tall Secretariat building. Fold and glue the main part of the building into a rectangular box.

Cut out the roof of the Secretariat. Fold the tabs down and glue the roof into the top of the rectangular box. The roof is not at the top of the walls but is recessed slightly. Push the roof down until the tabs of the roof meet the tab of the walls. Use a stick or blunt pencil inside the walls to push the roof upwards if necessary to make it level.

Cut out the glass south wall at the end of the General Assembly. Score the side tabs on the back side of the paper and fold them forward. Score the top tab on the fron of the paper and fold backward.

Glue the south wall inside the walls of the General Assembly. Match the side tabs inside the end of the walls.

You can add more detail to your model by adding the dome of the General Assembly building. Curl the side walls of the dome against a round dowel or pencil then glue the tab of one end inside the other to make a round cone shape. After the glue dries, fold down the round top of the dome and glue to the walls of the dome.

Glue the dome in place on the rooftop with the seam facing the south end of the building.

Cut out and assemble the rectangular box of the Dag Hammerskjöld Library building. If you'd like to add more detail to your model, you can cut out the thin upper level of the library. Note that the two long sides of the piece have a slight concave curve. Fold the upper level into a rectangle and glue in place on the rooftop of the library.

Cut out the rectangular roof piece and roll it against a round pencil to give it a slight concave curve. Then glue it in place on top of the upper level walls.