Houx Hill lies north of Byrness Village and Catcleugh Reservoir and you can bag a few more hills as you hike up to this one.
From the parking area, cross the road and look for the little finger post lurking up in the trees which then skirts a house and garden.
Follow the permissive path which takes you up onto Byrness Hill.
Then just continue to follow the path north past Saughy Crag and onto Houx Hill.
Follow the route above or find it on OS Maps. Just under 3km to get there, but with 288m of climbing,