Replace the commons with PR (STV on constituencies c. 6 times the size), replace the lords with people who have been in the commons for 20 years. Ensures fresh blood in the commons and removes the need to pander to the short term elections in the lords.
I think there's value in having an unelected second chamber, because the lords are freer to broach unpopular but important subjects. Nevertheless imo it would be much better to have them randomly chosen from society.