Todmorden-based Straw Works were chosen to demonstrate their skills at Grand Designs Live with Kevin McCloud at the London Excel exhibition Centre.
Straw Works built a multi-purpose office building from straw during the show, whic h ran from May 3-11, and which is now for sale.
The firm also ran workshops on building with bales, clay plastering and working with lime and encouraged the public to join in and discover the benefits of building with straw.
Director Barbara Jones said: “It was absolutely brilliant, we were very popular and really drew the crowds.
“Everybody loved what we were doing. They’d never seen a building made of straw before so they didn’t know what to expect.
“But some people came back day after day to see the build progressing and people were watching it on Facebook.
“It’s quite an accolade (to be chosen) and a testament to how we’re doing.
“They’ve asked us if we’ll do the show in Birmingham in October too.
“It will definitely result in more business for us.”