Possible Clues:

• Insulating layer perhaps seals edges of glasshouse
• Hull is supported by good English fat
• One with pounds to spare, say, turning back on school
• "Hodge" follower
• School gate disheartened fat kid?
• See 19-Across
• Squat, fat and flabby person
• Fat chap from school, say, retired
• ''Hodge'' follower
• He needs exercise after eating hot dogs regularly?