not really. a gigabit unmanaged switch is about 10 quid these days and you can get older enterprise access points from Aruba for about 15 quid on eBay. or a slower consumer unit from TPLink on Amazon for about the same price.

just use a switch and access point in the shed instead of a router. you would have to make sure you get all the router specific settings turned off and some routers don’t let you do that. if you are unsure about it, access point and switch is much simpler.