just a few minutes ago i saw a documentation about skyscrapers on tv.
they said, that the taipeh 101 skyscraper was built as a megastructure, meaning that several big steel girders form a cagelike skelleton called megastructure.
interesting fact, considering that nihei studied architecture...

now is the question: who used it first? nihei or the skyscraper-builders?

or was it a concept that existed for a long time

more interesting would be the dyson sphere issue..

i don't believe that the complete megastructure is a dyson sphere, symply because there isn't enough materia on earth to build such an enourmous construction.
also the builders don't really work together, they just build whatever comes to their "minds".

sorry, but..... dyson sphere?? oO
befor the chaos, the builders were under control, i think. but who controlled them?

i think that tsutomu read or hear about this subject in any books, magazines, channel of radio or inclusive in architecture. And he keep this concept in his mind until he decides make a history of sci-fi based in this idea of the Megaestructures: Blame!
During Blame! he, and the Studio Voice, makes Megalomania with the same idea applied to the reality.
The world of Blame! its imposible to realize, for this reason he invented the Builders and put that machines in the story.

P.D after read the others replies: Can be that the builder use technology more advanced from another world? In Noise Nihei write that the metal paste used to make the estructure was import from a place of beyond the orbit of the solar system.

Maybe it's just me but dosen't a dyson sphere eventually become extremly hot and that life wouldn't be really sustaniable e.g. all the fishermen would fry in hell!!!

I'm taking stuff from the 'Dyson Sphere FAQ' http://www.nada.kth.se/~asa/dysonFAQ.html#HEAT

'Even if the civilisation living in the Dyson sphere did its best to store available energy, thermodynamics eventually wins and the sphere begins to radiate away energy until equilibrium is reached.

Its temperature becomes
T=[E/(4 pi eta sigma r^2)]^(1/4)

where eta is the emissivity (=1 for a blackbody), sigma the constant of Stefan-Bolzman's law (5.67032e-8 Wm^2K^-4)and E the total energy output of the star measured in watts. '