That's odd... I edited this post some days ago, and it worked fine, but now it was changed to the origional post without the new image... Odd. Perhaps it's just me. Anyways, thanks for the critics guys, here's the render I've rendered at school using mesh-lights as sky, sun and interior-lamps. I'm gonna try to light it by a physical sky with a sun and with mesh-lights as lamps inside.

EDIT
Heya guys.
This is a little project I started yesterday because I will need to do an architectural project soon and need to practice. I have some questions so please help me out

The building is created in Blender in about two hours and is based on a building in Purmerend, the Netherlands. I've rendered this night-version for 6,5 hours on my AMD Sempron 3000 with 1 GB of sloow memory. The scene is lit by several tiny mesh-lights. (I couldn't get a nice render out of it until I discovered the Linear/Reinhard button (now turned to Linear) and finally was able to modify the power of the mesh-lights. (Probebly not, but that was what it seemed like.)
Origional render:

Over-exposed with PS for fun:

I've rendered a day-light render at school, but since I wanted a sun and physical sky AND some mesh-lights, I couldn't for some reason. Therefor I chose to lit the scenes just by mesh-lights (bigger ones for sky, smaller one for sun and some tiny ones as lamps in the building). But is there a better way to render a scene quickly (as in not too much render time) looking very pretty and convincing as a daylight scene but also with some mesh-lights? Please help me out. Also, is it faster to render a scene with a sun and physical sky or with mesh-lights around it?
The daylight render (from school) will be posted on monday since it's weekend now and it is rendering during the weekend.
Ow, and is it possible to render a scene with a picture like below (but than high-res) as a correct background, perhaps even liching the scene? That'd be cool!

Cheers
Sander