  Energy efficient technologies are particularly important for social housing
settings: they offer the potential to improve tenants' wellbeing through
monetary savings and comfort, while reducing emissions of entire communities.
Slow uptake of innovative energy technology in social housing has been
associated with a lack of trust and the perceived risks of adoption. To
counteract both, we designed a communication campaign for a retrofit technology
for heating including social norms for technology adoption and concretely
experienced benefits. We report two randomized controlled trials (RCT) in two
different social housing communities in Belgium. In the first study,
randomization was on housing block level: the communication led to significant
higher uptake rates compared to the control group, (b = 1.7, p = .024). In the
second study randomization occurred on apartment level, again yielding a
significant increase (b = 1.62, p = 0.02), when an interaction with housing
blocks was considered. We discuss challenges of conducting randomized
controlled trials in social housing communities.
