Add footer based on header building block

[WGP]

can anyone point me in the right direction as to how I can add a footer building block based on the header building block selected?? We have templates for all our city locations. the content of the templates are identical for all cities and only the headers and footers are different. I created the building blocks for the header and footers and I want to create 1 template that ALL cities can use simply by adding their local city header/footer. It works as it is now however its a 2 step process(add header...then add footer) that I would like to change to 1 step

TIA

WP