Hi, congratulations for your first commercial Blender project! I spent so much more time understanding Blender until I was able to make anything worthwhile… but again, it was in the days of blender 2.4 so maybe the new UI is easyer (I’m just trying to make myself feel better)
Your first attempt looks very good. The wood and grass textures are nice and the image looks cheery and happy the way architect’s clients like to have them. As you know already the glass is the toughest to get right and is the first thing you notice in a project like this. It’s mainly about what it reflects. Transparency will improve it but also making it a bit darker and less blueish - in fact like the conservatory windows.
Now I’ll come to the constructive criticism
In the elevated view, I think the horizon line is to low, it should be at the point perspective lines are horizontal, about the top of the top floor windows. I like your background image though.
The white walls are a bit too bright and flat and some edges are not visible on my screen. The umbrella also.
The roof and floor textures have a good tiling but appear too perfect, you could try mixing some large scale noise or other types of textures to the main tile. The paving is a bit too gray, even if the actual material to be used is reffered to as “grey” it won’t necessarily look gray in sunlight - you can make it a bit warmer. The wood textures show bad tiling and look a bit overscaled as well. For the wood panelling for instance there is a vertical line and a dark dot that are too obvious and could be edited out in the texture file.
I am trying to develop a blog on architectural rendering with Blender, maybe you can find something helpful here: Blendermama
I would be glad for any suggestions on improving it from people interested in this particular subject.