Offline Architectural Tool just to figure the Math and Planning

Are there any good CAD tools that can be used to create by-the-numbers type blueprints while offline? I'd like to figure out my dimensions and math without logging into SL, then create the component objects and precision build by punching the numbers in once I'm logged in. Please include URL's to product home pages. I even like to go so far as using scripts to just rezz the objects with their shapes, dimensions, rotation, and position already precalculated from the blueprints to do the precision building.

I did run a search on the forums for this information before posting this request. People mentioned 3D MAX and Maya. Google search for those turns up thousands of matches and is pretty much useless. From what I can gather tho, that's not the kind of tools I'm looking for.

I know of something that meets NONE of your requirements, but thats fun to try without needing to be a rocket scientist. I use it for planning and visualizing developments quickly in RL.

SketchUp - www.sketchup.com

Halbert, there are many CAD systems available for casual residential work. Your emphasis on accuracy is crucial, but I don't recommend a CAD system as a toolset for SL. When I started learning how to design structures using prims I had to set aside 'CAD thinking'. This was hard, because I'd spent considerable time learning CAD thinking for RL projects.

When people make design decisions, they are sometimes subconsiously influenced by their tools. For example, in RL a homeowner thinking about hiring an architect for his new residence might use a simple CAD system to make a floorplan. CAD systems make floorplans easy. People love to tinker with ideal floorplans that have no allowance for thickness of walls, no provision for the mechanical systems of a house, and no sensitivity to cost savings inherent in standard versus non-standard dimensions of construction materials. They present their ideal floorplan to the architect, and point at an image of a built house to *handwave* indicate that this is what it should look like on the exterior.

In SL you see many many examples of box and pod construction. It's the obvious first step for beginners who are thinking in terms of our system of prims and prim limits. Beginners assemble a structure using the largest size of box prims and cylinders, often arriving at the same look: a box with round bays textured as bow windows. People often make the upper stories of a building identical to the main level. Shift drag to copy a linked set makes that design decision very easy. Acquiring experience, people think more in terms of the platform, factoring in things like joint accuracy, rendering, camera angles and lag, but it's still thinking in terms of a toolset.