@tommyk said: I do extensions and renovations using Sketchup and LayOut exclusively. I make the following models: survey model (of existing) - simply modelled. design model - for finishes, furniture layout, and discussions with client construction model - for technical putting together of buildings I have in the past tried to put all those models into one, using layers for demolished walls, etc, but it soon got tedious, and I work in the above way now. Keeping models separate also has the advantage of keeping model sizes down and therefore your modelling speed up. I don't use another 2D CAD program at all. I do my sketch plans on tracing paper, then go straight to Sketchup to get my accurate drawings. That's like the way I've outlined below. I do sometime split the model into different parts but I'm always afraid of not keeping the main information centalised as I can get mixed up between version changes. I might take particular sections of the build and show them separately but the central model is paramount.

Have you looked at the SketchUp model and the LO project on a different screen? It could be the screen you're working on is set such that it is skewing the way things making them appear brighter than they really are. Without seeing what you're seeing, it's difficult to tell for sure.