Hycrete, which makes a chemical additive that makes concrete waterproof, raised $15 million more to expand operations and in the process underscored how green building investments might be judged in the future.

First, the news. Mohr Davidow and others put in $15 million into the company so that it can begin to open factories in different parts of the world to sell more of its waterproof chemicals. Hycrete is already shipping product and its chemicals have been included in about 80 mega-construction projects around the world.

Erik Straser, a partner at Mohr Davidow, said that waterproofing concrete with Hycrete’s material is cheaper than traditional materials.

“It is 50 percent of the cost of waterproofing now,� he said. Currently, builders pour concrete, then wrap it in waterproofing material. With Hycrete, concrete makers pour the company’s secret liquid into concrete while they mix it. Builders don’t have to hire waterproofing subcontractors. Construction time is also cut, thereby saving money. The general contractor and building owner both save.

Some believe that green buildings will be one of the few markets that won’t require subsidies. So point one: green building material companies or contracting companies will be touting that they are cost-competitive now. If they can’t, it’s going to be a tough sell. They just won’t look as good as investments as others in the field.

Another interesting point is how Hycrete operates. It does not plan on licensing its technology. Instead, it will set up factories around the world and sell the liquid to contractors and concrete companies. Why? The formula is protected in part by patents and part by trade secrets. There is always a risk of being copied. Hence, point two: green building companies will own factories like solar and biofuel companies. But if they act as component supplier for larger products (i.e. making chemicals instead of making concrete) they can cut down their manufacturing footprint.

Hycrete CEO David Rosenberg by the way added that waterproofing concrete also makes it recyclable. On a side note, his grandfather invented the formula for Hycrete about 13 years ago.