When buying new construction your agent can:
Assist in finding a respectable builder
Stand up for your interests with the site agent & builder
Review your contract & provide expert advice
Negotiate upgrades & pricing with your best interest
Review upgrade choices & analyzing pros / cons
Recommend the best financing options
Oversee a home inspection

If you are thinking about purchasing new construction but think you do not need a real estate agent to represent you, consider the points above. When you visit a new construction site, there will be an agent on site. That agent represents the builder, who in this type of transaction is the seller. So even though their agent will offer to work for you, consider first that this is like having the seller’s agent be the buyer’s agent too. Being that they work for the builder they will have the builder’s best interest in mind, not yours. 

By hiring your own agent, you will have someone to stand up for you in negotiations for upgrades, pricing, timelines and etc. In addition, all the nuances that apply to new construction in the form of paperwork and inspections that are less familiar will be handled by your agent. In many cases, you will need to bring your agent with you to the first meeting on a new construction site, as some sites will have you sign paperwork stating you don’t have an agent or even will not allow you to have your own agent past your first visit to the site.