Vicky Penner from Save Lewisham Campaign said the group are delighted the decision has validated their campaign.
More top news
Arthur Simpson-Kent killed Sian Blake and their sons at their bungalow in Erith, south-east London.
Samples from 95 buildings in 32 local authority areas have failed fire safety tests - 100% of the cladding samples submitted.
The double zip line will allow riders to travel at high speed close to the capital's famous landmarks.