The short answer is yes. Most buyers wouldn't think of buying a resale home without an agent. A brand new house is similar, but depending on your state, things could be vastly different and a buyer would be smart to hire a professional.
In Colorado, for example, builders are not governed by the Department of Regulatory Agencies. When it comes to new homes, the builders rule. A buyer should remember that no matter how nice and persuasive the builder's sales person is, he/she works FOR the builder, NOT the buyer. The salesperson may very well not mention that you could have received a design allowance or that you could have had the lot premium reduced. The typical builder contract in Colorado is also heavily favoring the builder.
What if there is a problem during the building phase? Are you ready to go to battle with the builder? A good agent will represent you and take care of any issues that arise.
A builder also will probably not suggest having an inspection performed on the home. It's brand new so what could go wrong, right? Unfortunately, builders and subcontractors are only human and mistakes will be made. A builder will try to tell a buyer that you can let the builder know of any issues after the sale and they will take care of them. However, will you be able to tell if the insulation is installed correctly in the attic? This is just one example of something that a typical buyer will never check on, but a good inspector will do so prior to your purchase.
A builder also will probably not suggest having an inspection performed on the home. It's brand new so what could go wrong, right? Unfortunately, builders and subcontractors are only human and mistakes will be made. A builder will try to tell a buyer that you can let the builder know of any issues after the sale and they will take care of them. However, will you be able to tell if the insulation is installed correctly in the attic? This is just one example of something that a typical buyer will never check on, but a good inspector will do so prior to your purchase.
Last, but not least, a common misconception is that the buyer is going to get a dramatic "deal" on the price of the house by not using an agent. All builders build that commission into their marketing expenses. In other words, you will not see a "deal" come your way without an agent and in fact, you may end up paying more than you need to!
The key with new construction is to make sure that you know which agent will be representing you before you visit the model homes. The builder will require you to sign in and indicate if you are using an agent. Many times if you don't do so and want to write an offer on a home at a later time with your agent, the builder will not allow the agent to represent you.