Sounds as if you are after a CAD programme. Having said that there is nothing wrong with your request as AI has a measurement tool although it does not work quite the way you want it to. To that end Illy has a plugin called CAdtools which does this job and more the only thing it adds $200 to the price of Illy making this programme really expensive while they are many free CAD drawing programmes around and one of the better ones is Siemens http://www.plm.automation.siemens.co...idedge/free2d/

I do all my woodwork drawings using this programme but it is only 2D but it does me. Like most CAD programmes it runs from a command box which for a little while seems strange but a fter following their vid. tutorials you will easily get the hang of it. You can bring your files into Xara for rendering to improve your overall look but it is not the place for editing the file.