The building, owned by the Fforestfach Trust, allows the group to offer support to children and young people in care or leaving care.
The DIY SOS team had just 11 days to build a brand new support centre.
J Randall Roofing completed the flat roof, it was hands on deck for 3 days to complete the roof in time for the big build.
You can watch the project by clicking here
— BBC Children in Need (@BBCCiN) September 7, 2017