If you'd like a design and technology challenge then why not create a Borrower house from things that you can find around your house and garden? I've added lots of documents to help inspire you including pictures and words from the text itself. You could make a home in a shoe box paying attention to lots of little details, or you could make your structure from scratch and reinforce it if it's not strong enough. At the end there is a form for you to evaluate your work. If we were in school we would have done this with our air raid shelters too! We can do that when we are back together!
Make your own gas mask... the children missed out on this, so I know they'll really want to do it.