You should have several professional deck companies come and look at it. Knowing the different options and their costs is going to help him make decisions. I recently built a deck over a concrete slab and there are A LOT of decisions to be made. With estimates from professionals (both wood and composite) it made it easier to know what I really wanted. I also got a good education on all the different materials.

Since it’s an elevated structure, there will be a staircase involved. Steps are surprisingly expensive. We have two small staircases at either end of our slightly elevated deck. They added more to the cost than I thought they would. Railing is another item that requires a few decisions.

The composites are pretty similar but color and cost will vary.

Thanks for your input! Very helpful.