Guidelines to protect Guernsey's environment from large-scale building have only been used once in 10 years. Politicians voted in favour of using Environmental Impact Assessments more than a decade ago.
The assessments are supposed to make it compulsory to fully measure the effects of any large project on traffic, air pollution and nearby homes.
The planned waste facility at Longue Hougue is the only project to have been subjected to such an assessment.
Environment Minister Bernard Flouquet said he was confident more will be carried out in future.
President of Guernsey's National Trust Roland Ogier said he believed all building projects should be subjected to a basic environmental checklist.
He added that he was also worried that while large sums of money could be spent on assessing high-profile schemes, the impact of smaller projects could be overlooked.