First ask the cubs as sixes to come up with ideas of what they would like in their ideal meeting place. Then build using junk modeling materials available. Allow the cubs time at the end to view each others model and to allow them to talk about theirs.
Recycling - cardboard boxes, plastic trays, foil, paper - anything that can be used for modeling
Sellotape, paint, glue
Scissors, table covers, paint brushes and paint pot.
Paper & pencil to make note of their ideas
Ask the cubs to bring an old t-shirt to wear during the activity.
First ask the Cubs as sixes to come up with ideas of what they would like at their ideal meeting place. Write these down so that they can refer back to them while building. It doesn't need to be a building, you may want of think of different spaces - adventure, activity, relaxing, to help them focus their ideas. Make sure every Cub gets chance to have a say. Should take around 5 to 10 minutes.
Using the junk modeling resources build their ideal meeting place. Will need to remind them of their initial ideas as once they get building they tend to forget.
Spend 10 minutes at the end going round as a group to look at each others models and ask someone from each six to tell you a bit about it.