Mine are by Broadfield, http://www.broadfieldstables.com/
They are 24 years young, still going strong. Have had the felt roofing replaced twice- the most recent time this year. I do creosote them annually, or bi annually at worst. Only small amount of rotting on one plank, which ahs been sealed and replaced.
I have 3 stables, a corner box and a feed store,and all are still holding up very well. Can recommend them highly- although I see fom website, they have been taken over by redmire but hopefully the product will be as good and have as much longevity.
west of england stabling are doing a 120ft complex atmy livery yard... consisting of 5 14ft stables tackroom,feedroom,farrier area and haybarn.First halfcompleted and is very good...strong,smart well built and very sensibly priced
I've got a national stables yard, it was built about 2 1/2 years ago and still looks pretty new! Its great! Really tough, and really good value for money! They're worth a look because they don't do much advertising, we only found them because we drove past their main office....