A true CAD laptop is in the $2500+ range. Just bought one for my graduate architecture student daughter this past July. Core i7, 2TB drives, 32gb, nVidia K4000… But it’s the size of a mattress… With a serious graphic card (discrete graphics) you should be OK. My daughter used a Lenovo Thinkpad 420 with discrete graphics for 4 years for undergrad Architecture and OK, it got slow at the end and you won’t render the Burj anytime soon on it but for CAD a basic discrete graphics and core i7 should be fine. Don’t get anything more than 14" tho but get a good display, not the pitiful ones.
Or get a Surface Book 