Today we bring you an old tale. It's the story of the three little pigs and the big bad wolf that blew down a house made of straw and one made of sticks. The only house left standing was the one made of bricks. Now there is new evidence to suggest that houses built with bales of straw can be very strong. They are also very environmental. Pete Walker is a professor at the University of Bath in Britain. He and a team of researchers there have built a house made out of straw bales and hemp material. During the next twelve months the team will study the effectiveness of these materials in home building. Professor Walker says there are many good reasons for using straw. Professor Walker: "One of the benefits is it's a relatively inexpensive renewable material that's readily available." He also agrees that straw takes in carbon dioxide as it grows and helps the environment in other ways. So it can be seen as having no harmful effects on the environment. Professor Walker: "The straw bale walls are relatively thick and so all that straw provides very good thermal insulation. So we make buildings that require very little heating in the winter or indeed very little cooling in the summer. So they require very little additional energy." Professor Walker says this reduces home operating expenses. It also reduces the effect on the environment. He says the current interest in straw bale houses is a direct response to the problem of climate change. David Lanfear owns an eco-friendly home building service in the United States called Bale on Bale Construction. He says he laughed when some friends first told him about houses built of straw. But after doing his own research, he learned that building with straw bales made a lot of sense. He has now helped to build more than ten straw bale houses and says the building material is becoming more widely accepted. To build the houses, he fills a wood frame with tightly packed bales of straw. Next he coats the walls inside and out with layers of clay plaster. He says the common ideas about straw houses continue, including stories about the threat of fire. Mr. Lanfear says straw bale houses have done well when tested for fire resistance. And he says his builders use the same building methods as traditional builders to keep out rain. David Lanfear: "We use what we call good shoes and a good hat, and that would be a solid foundation and a really good roof." According to the passage, we know that   _  .
there is some experience in building the straw houses the house made of straw bales is the same as the traditional one the house made of straw bales is still under research it's uncertain that the straw house can be very strong