A pre-inspection is done by the sellers before they list their home for sale. It is usually the same as a buyers inspection with regard to the price and time frame to carry out the inspection. So for a typical 3 or 4 bed home is can cost approx $500-$600 and takes 3-4 hours.
Different areas do seem to have different recommendations as to whether to have your home pre-inspected. In larger/busier markets, such as Vancouver/Toronto they have been popular as in these markets there have been a larger number of multiple, subject free, offers and this allows buyers to have more information prior to putting in an offer, especially if they have not had time to do their own inspection.
Here in the mid Vancouver Island region they are not as popular, although they are still carried out.
The advantages of doing one are:
1 - As a home owner you know if there are any issues to be addressed prior to listing your home for sale. This allows you to either price you home according to these issues or rectify them - although it is better to rectify them as buyers may well have a different idea as to how the issues discovered might impact the price of the home!
2 - This can help to avoid price re-negotiations after an offer has been accepted and before subjects are removed as the issues have already been rectified.
3 - Here in BC it is very important for sellers to disclose anything that they are aware of that is wrong with the home. This can help with showing that the seller has done their due diligence with regard to what they knew or did not know about the house. However, this also means that if the inspection does pick up a defect in the home the owner is now legally bound to disclose it, even if they were not aware of it prior to the inspection.
4 - It can encourage fewer subject clauses which are beneficial in a multiple offer situation and also mean there could be one less subject clause that could cause the deal to collapse.
However, as I mentioned, in this area they are not as common and it is more normal for the buyer to arrange for a home inspection and to have this as one of their subject clauses. In fact it is not unusual for the buyer to do a home inspection even when there is already a pre-inspection available as at the end of the day it is also the responsibility of the buyer to do their own due diligence when purchasing.