I know this is an old thread, but the replacements hoods can be purchased from: https://houndhouse.com.au/product/houndhouse-replacement-hood/
They come in four sizes and will fit the HoundHouse frame, just like the hood that it came with. They are as strong, because they are the exact same product.
If anyone has any questions about getting the right hood, how to fit it or any other HoundHouse replacements parts, we are always happy to help.
Thank you
Tom