A lot depends on exactly what the substrate is. If it is above ground-storey level, the problem is simpler.
If it is on a ground-level storey, and if it is concrete,
and has been properly laid down with appropriate vapor barrier, not just plastic film, then you can use either wood or laminate.
But if there is any chance that moisture can be wicked up from the subsoil or concrete with no interleaving vapor barrier, then the intelligent choice would be either
(1) go with the option that would be cheapest to replace, should swelling, mold, warping or any other problem due to moisture wicking arise, or
(2) have the substrate reviewed before construction. It may be fine; or it may need to be dug up and replaced using approved procedures and materials, making very sure that you use a well-qualified contractor who
1. understands the principles involved, and
2. guarantees his/her work, and
3. agrees to municipal inspection before the last large payment is made on the project.
p.s. Please check into the latest alternatives to wood-look laminate. Some of the vinyl and laminate floor covering patterns are really lovely, and are considered a little more tasteful, because they are not imitating anything.
(It's like the difference between real mink and faux-fur mink: faux is tacky. Unless of course you are an animal-rights activist. In which case, why imitate real fur in the first place?)
A strong alternative I would look at is natural-fiber covers such as hemp. They go right over the floor or sub-floor, and they breathe. Unlike most commercial "carpeting",they are made of non-toxic fibers, and don't need a lot of chemicals to prevent them from changing color,molding, or degrading in sunlight. In fact they just need reasonable cleanliness, fresh air, and sunlight to be safe and hygenic.
Other natural fibers are made from corn leaves and stalks, sea grass, jute, and coir (coconut-husk fiber). They are washable, and when you discard them, they are bio-degradable: they can be thrown in the compost pile at the end of their useful life and will break down with little or no damage to the web of life.
So usually you can see your kids and grand-kids crawling on them, picking up toys and putting them into their tiny mouths, -- whatever - without well-grounded fear that they will be harmed.
You have not mentioned carpeting as an alternative. So I'm sure you're aware that almost all carpet is made from petroleum byproducts and synthetics such as polypropylene, nylon and acrylic. Also, it’s usually treated with stain or soil repellents, antistatic sprays, artificial dyes, antimicrobial treatments, that are toxic to humans, especially children. The backing could be made from vinyl or synthetic latex. Padding can contain PVC, urethane, and other suspect materials.
And as for 'nice cheap' products imported from third-world countries, which don't even protect their own workers from lead or other toxins, what do you expect?
A hard flooring material, with natural-fiber rugs, is healthier for people without allergies. And much healthier for people with allergies. But for people with allergies, no rugs is best.
p.s. I have laminate faux-wood in part of my living room.
