Recent green building certification programs have put a strong emphasis on occupant health and well-being. For recently emerged WELL certification, we lack evidence about its effectiveness in relation to occupant satisfaction, productivity and health. Here, we compared the results of occupant satisfaction with the indoor environmental quality (IEQ) obtained from the same cohort of employees who transitioned from three non-WELL (two BREEAM and one conventional) to three WELL-certified office buildings. For two out of three building pairs, we found a statistically significant increase in building and workspace satisfaction after relocation to WELL buildings. However, for 55 % of compared cases, there was insignificant difference as the result of relocation. The positive effect of WELL certification was evident for parameters such as building cleanliness and furniture, but there was no difference in satisfaction with noise and visual comfort. Relocation from BREEAM to WELL buildings had insignificant effect on satisfaction with IEQ, except for air quality in one case. Regardless of the certification label, buildings usually did not attain the 80 % standard satisfaction threshold. The satisfaction scores did not alter during the first year of working in WELL buildings. We also observed that the level of certification did not scale with the overall building satisfaction scores. Comparisons between the occurrence of Sick Building Syndrome (SBS) symptoms and self-reported productivity scores revealed insignificant differences between WELL and non-WELL buildings, except for symptom of tiredness that was lower in WELL buildings. The effect of Covid-19 measures interfered with the self-reported work abilities of 78 % of occupants.