Radon testing for a Colorado real estate transaction is performed by placing a certified electronic testing device in an appropriate location in the sealed home for 48 hours.
If you want a radon test, the inspector can begin the test 48 hours prior to the inspection so that it will be completed on the day and time of the inspection. That will save you 2 days. Otherwise, the radon test can be started during the inspection and will be completed 48 hours later. A radon test can be requested or added to an inspection at any time before or during the inspection.
Once the radon test is completed, the inspector will provide a radon report - usually within 12 hours - identifying the level of radon detected and comparing that level to the EPA guidelines.
If the level is unacceptably high, It is up to you and your agent to decide if you wish to ask for the condition to be mitigated. Likewise, it is up to the seller whether he is willing to accede or not to your request if you ask for mitigation or compensation.
A good radon mitigation system is very effective and has a low operating cost. In general, it consists of a small vacuum system installed such that it removes air from beneath a basement slab or a rubber membrane installed in the crawlspace to exhaust radon gas to the exterior before it can enter the home. Installation cost can be as low as $1200 for a small home.