Can a construction company owners son act as realtor and represent both the seller(his father) and a buyer ?

A person's son is permitted to act as a realtor and represent both sides.

As long as the son is licensed and both parties consent to the dual agency, it is legal and very common. The fact that he is the son of the seller has nothing really to do with it.

While it is true that this is generally accepted practice despite the nepotism, there is a greater likelihood of a conflict issue arising. The fact is the broker/son is a fiduciary for both parties when he enters into a dual agency situation. He must have a written consent to act in this manner. Any party signing one of these should make sure they read the dual agency consent form carefully as some rights are given up with respect to the agent's duties. Regardless, dual agency does not provide a license to fail to properly advise either of the parties in order to further the interests of the other party to the transaction. In other words the broker can't just favor his father to the detriment of his other client, he must disclose any real conflicts to both parties. On another note, the reason the broker can offer a better deal is because he is handling both parties and so, although each side pays less commission, he gets both halves and so still makes a tidy profit. The reason the parties' agree to the dual agency is to get the better deal, less commission paid. So the parties receive something in return for agreeing to the dual agency. It actually makes sense.