It was not possible to determine which design standard had the higher water retention, the conventional method or the design based on foreign standards. The sample size was too small to be able to determine which was better with statistical accuracy.
Það reyndist ekki mögulegt að sýna fram á hvaða hönnun grænna þaka hefði hærri vatnsheldni, hefðbundna aðferðin eða hönnun að erlendri fyrirmynd, þar sem úrtak mæligagna var of lítið.