Archtectural Visualization - Staircase

hi @all,

started this project several months ago, but was so unsatisfied with the first results that i stopped quite soon after starting.
after installing luxrender (thanks to jonathan williamson at blendercookie btw), i tried rendering it again and it turned out like what i wanted really fast.
inspired by one of the pictures in the gallery at blender.org. i tried to do a very simple scene in the style of an architectural visualization.
im looking for any criticism and for hints on the very bright light where the sun shines into the building (lower left side) and on the handrail: i wanted it to look like a metal rail with a black varnish which i obviously haven’t accomplished… how to do that best in luxrender? normalmap? just a special material setting? any hints?

modelled in 2.49, materials for luxblend in 2.5 beta, rendered with luxrender 0.7.1