....trying to rank for some very competitive local terms... rank better without building out an entire site.
You have a "fighter wannabe" who is skinny, untrained, smokes, weak,.... and he wants to fight the heavyweight champ.
You can give him pep talks and send him into the fight or you can delay the fight and get him ready.
For this client I would explain that fighting on the web is a battle of resources. He ain't got much right now, so don't expect much.
But, you can point out some ways to get some resources and suggest what those resources might be. This company is building lots of attractive homes. Each of them can be a marketing message for the community where it is located and a marketing message for the style of home. Both of those are optimization keywords.
Getting a photographer to visit the homes, take lots of photos then someone at the company who knows about the homes can dictate some information about each photo. Get that together in an optimized page for "Custom Home in East Arlington - Split Level".
These pages serve many purposes. They can be used to market the home. They can be used to showcase great work and demonstrate the range of homes that this company builds. They can be used to showcase a presence in many neighborhoods. They will collect traffic for their keywords. People will pin them on Pintrest, People will share them on Facebook... We like this!... We bought this!.. Yay!... This is beautiful! Subcontractors might refer to them, real estate agents might refer to them. Any builder who does not want that is nuts.... dumb even.
Tell this client. YOU NEED TO DO THIS! If this small investment sells ONE HOME you got your money back many times over.
I put more effort into sellin' stuff for $5 than they are spending trying to sell $500,000 homes. Duh?