British construction firms are seeing their businesses benefit from using sustainable design practices and more environmentally friendly building materials, and they expect the value will continue to grow, says a recent survey of U.K. construction firm executives.

The January analysis of 100 senior executives at U.K. companies with more than 100 employees done for engineering firm Patrick Parsons, found that 83% of respondents say “green credentials” had provided them a competitive advantage.

Two-thirds of the respondents said sustainable design is adding value to current projects, with 68% expecting that value to increase10% to 20% over the next three years, and 18% saying they expect as much as a 50% boost in the same period.

While the survey only questioned U.K. industry executives, it dealt with many of the same sustainability issues elsewhere, including the U.S. market.

When asked to pick the two most important aspects of sustainable developments, the most popular answer was that projects need to be built with flexibility to accommodate future changes after initial construction, through a building’s lifetime and demolition. 

However, more than 60% of respondents pointed to challenges such as material supply chain issues, a lack of materials with a lower carbon footprint and not enough government support as hurdles now hampering efforts to achieve net-zero carbon. 

“There must be a development in the materials used and planning rules must change if we are to decarbonize legacy buildings and improve their performance,” Conor Murphy, senior partner of structural engineering at Patrick Parsons, said in a statement. 

The survey comes after the U.K. hosted the United Nations Climate Change Conference, COP26, in November in Glasgow, Scotland. In the survey, 86% of respondents said they believe COP26 will accelerate positive industry advances in sustainability this year.