Surface-initiated Atom Transfer Radical Polymerization is an established technique for synthesis of polymer brushes via "grafting from" method. However, dynamic behavior of surface-tethered macromolecules during their growth requires more detailed studies to obtain uniform polymer brush films. It was addressed here by varying solvent composition in grafting of poly(N-isopropylacrylamide) brushes. Complementary in situ (quartz crystal microbalance) and ex situ (atomic force microscope, spectroscopic ellipsometry) techniques were employed to investigate the influence of methanol molar fraction (x(Me)) in methanol/water polymerization mixture on the brush growth. Grazing-angle polarized FT-IR spectroscopy was used to monitor macromolecular arrangement in the brushes. While achieving controlled, uniform and relatively fast growth of macromolecules is challenging a compromise may be reached by tuning solvent composition. The most balanced conditions with this respect were found in a narrow solvent composition window at ca. x(Me) approximate to 0.16 and below 0.31. The results may be applied for tailoring polymerization conditions of other polymer brush systems. (C) 2016 Elsevier Ltd. All rights reserved.