Oh no, you have some in the house? They would be much happier outside.
Okay, on collecting the seed, the seed is so tiny it is like dust. So wait until the blooms are all finished the the seed capsules (the the bloom petals where attached) turn brown and almost crispy. Carefully cut the bloom stalk making sure to hold it upright. Place a paper bag over the top and quickly turn the whole thing (bag and bloomstalk) upside down, so the bloomstalk is now upside down in the bag. Fold the top over and place in a cool dry place in your garage or house. In a few weeks they should be finished drying. Once they are nice and crispy dry, gentle massage the sides of the bag so the tiny seeds will fall from the capsules. Open the bag and hold the end of the bloomstalk and gently shake it against the inside of the bag. Remove bloomstalk and throw it away.
Using a piece of white printer paper, folded in the middle, empty the bag of seeds very gently (remember the seed is like dust) onto the white paper. You should do this in the house where there is not breeze/fans going, or you will lose your seed.
You will need an air tight container (small envelop, small glasine envelop, or the tiny zip lock bags), gather the edges of the paper together using the fold down the center to pour your seeds into your container. If it is a paper envelop place it in a ziplock bag, seal and place in the frig until the end of winter. That is when you will plant the seed.
The winter sow method works very well for sempervivum seed.
https://garden.org/ideas/view/...
