Major issues need to be overcome if the ultra lowenergy German Passivhaus is to take off in the UK, according to new research from the NHBC Foundation.<br> <br> The report, Lessons from Germany's Passivhaus experience, finds:<br> Building a Passivhaus is a major challenge to builder and designer, affecting its suitability to the volume market. <br> The cost of building a Passivhaus in Germany is 3% to 8% more than building to German Building Regulations. Reduced interest rate loans and grants in Germany help Passivhaus construction, but only one such loan scheme is available in the UK and no grants.<br> <br> Neil Smith, group research and innovation manager at NHBC, said: "Passivhaus is still in its infancy in the UK, but it is clear there are major issues that need to be overcome if the Passivhaus standard is to take off." He added that it is questionable whether Passivhaus is a realistic solution for the volume market at present.<br> <br> 165 Passivhaus buildings were completed or under construction in the UK last year. 37,000 have been built worldwide.