Our fence top cat barrier brackets could be the answer. (Although you could attach the brackets to wooden battens to extend the height of you fence, if below 6ft. CAT BARRIER BRACKETS. Brackets are made from strong, rust protected stainless steel. ).
eBay
Plastic mesh 19.6 inches x 16.4 feet - poultry garden fence, dog barrier, easy to cut and durable animal proof yard fence
Aliexpress UK
Thoughtful Design Features: The cover at the door for easy for access, allowing you to roll up the fabric conveniently. User-friendly Maintenance: Cleaning this cat house cover is a breeze—simply rinse it with water or wipe it down with a damp cloth.
eBay
WPC Privacy Fence Panel 6x80 Inch Salt Spray & UV Proof 3000Hrs, Heavy Duty 250kg/m² with Hidden Clips, Splinter-Free Pool/Gard
Aliexpress UK
Thoughtful Design Features: The cover at the door for easy for access, allowing you to roll up the fabric conveniently. User-friendly Maintenance: Cleaning this cat house cover is a breeze—simply rinse it with water or wipe it down with a damp cloth.
eBay
Rustproof Landscape Fence Potted Plant Barrier Bendable Garden Border Animal-Proof Edging for Flower Beds Functional Yard
Aliexpress UK
Privacy WPC Fence Panel 12mm All-Weather UV & Termite Proof, Snap Lock System for Garden/Backyard
Aliexpress UK
Protective net 0.8 mesh PE balcony net fence net for garden terrace bird proof net
Aliexpress UK
Dog Fence Garden Fencing Animal Barrier Decorative Privacy Panels Rust Proof Divider For Outdoor Yard Flower Outside Pet Use
Aliexpress UK
1/2PC Garden Gate Spring Closer 8inch Universal Automatic Gate Spring Metal Fence Gate Spring Closure Rust-Proof Door Outdoor
Aliexpress UK
Rusty Wrought Iron Cat Halloween Fence Ornament - Garden Party Decor
Aliexpress UK