Ottawa Real Estate Board – The Ottawa Real Estate Board (OREB) is a non-profit industry association representing REALTORS® in the greater Ottawa region since 1921. Our comprehensive site provides valuable market statistics and resources for homebuyers, home sellers, commercial properties, as well as real estate professionals. The Ottawa Real Estate Board (OREB) is a non-profit industry association representing REALTORS® in the greater Ottawa region since 1921. Our comprehensive site provides valuable market statistics and resources for homebuyers, home sellers, commercial properties, as well as real estate professionals.