That was my design philosophy "look" like a light switch but with a lot of hidden functionality.
I settled on a page per room, for basic functions, but then any number of tabs on each page for extra functions. Also I use the first tab name as a label for the page, as it saves some more screen space 
The visible tab is highlighted in bright white. Clicking the scene tab name then slides in another set of controls.
As you can see from earlier posts, any extra requirements are being done via popups. These are triggered without the need of extra buttons where possible, by using e.g. a long press.
For example, a long press on a colour capable light shows the colour slider popup.
I plan to have a detail weather page triggered by pressing the weather icon, maybe even the clock etc...
I added 4 buttons at the bottom as place holders right at the start, but have only used 2 so far
And I might even get rid of them altogether, which would recover some valuable screen space
