Teaparty? =) You should activate shadows and some antialiasing. I think it will look much better if you do.

I take it you're new, so here are some quickfire tips to get your ball rolling. Make your main light 100% distant light, place behind houe pointing down. Make new area light at 60% place opposite main light. Turn off affect specualr. (light properties) Go to Global illumination, and turn ambient to 0% Make the grass (in modeler) a different surface to the concrete, and set saslite to use only named surfaces (grass) Turn off transparency for window, and turn reflection to 35% (surface editor) Turn on ray trace shadows, ray trace reflection, (render options) set camera AA to medium (camera properties), and re-render. Best of luck. Post agiain after trying to let us see how you get on. If you really wanna go nuts, run all lights to 0%, in global illumination turn on radiosity, set to interpolated, 4X12 or 5X15 if you think you comp can do it, and tolerance 0.0 have a good one.

nice modeling on the chairs and i like the texture on the walls. i agree with pentamiter...try using global illumunation

Looks like you've gotten some great rendering tips already. My two cents would be on the modeling bit... try keeping a tape measure by your side. As a general rule of thumb model everything to real scale. There's always going to be exceptions of course, but it's a good way to build up a library.