The UK decided in 2013 to bring home soldiers from across five units in Germany, leading to new development at Catterick Garrison in North Yorkshire.
The move was taken to save the Armed Forces £240m a year, but how has the revamp shaped up?
Catterick is now ranked as a 'Super Garrison' and – spanning 2,400 acres – it is officially the largest British Army base in the world.
But much of the architecture had become dated over time, and much of it was protected due to its place in history.
Robin Hartley, Area Lead, Army Basing Programme for North and Scotland, said: "It’s been a series of projects over 30 years of working across the UK and in Germany itself.
"It was a little bit unique and a bit different, it’s a very disperse site.
"It’s also got quite a lot of historic features and quite a lot of listed buildings. So the old pilot’s restroom from the Second World War – you can imagine that sort of iconic ‘ring the bell and run to the Spitfires and Hurricanes'."
He added that a lot of work went into preserving these historic sites during the expansion and new development.
Catterick’s Munster Barracks is comprised of what used to be multiple separate barracks.
At the heart of it is the Sandhurst block, a Grade II-listed building from 1938, left empty in 2009.
Untouched on the outside, it has been transformed in modern years – once a single-living accommodation block housing more than 400 soldiers, it’s now an office complex for more than 600 personnel.
After 16 months of work, it’s also the Headquarters for Catterick Garrison, including 4th Infantry Brigade, 1 Regiment Royal Military Police and 1st Military Intelligence Battalion.
Richard Asbery, Programme Manager, Defence Estate Optimisation, says the interior is now "unrecognisable".
"You’ve got open-plan offices where we could, you’ve got break-out areas, you’ve got conference rooms," he said.
Marne Barracks had to undergo a total makeover to welcome 32 Engineer Regiment after it left Germany, as many of the buildings dated back to the Second World War when Catterick served as an RAF base.
Another major development on the base was accommodation, with a step away from the traditional single living flats and the creation of 120 junior ranked bed spaces.
"It allows personnel to come back and spend some time as a group – gaming or watching on the bigger screens that we’ve incorporated into the rooms," said Mr Hartley.
Kitchen areas are also a new addition, alongside a private room for each soldier, to give them time for themselves.
More troops from Germany has also meant new facilities off base in Catterick, with civilians also benefiting from new shopping complexes and leisure centres.
Plans are in place for troop numbers to increase at Catterick by more than 50% by 2031, with more buildings set to undergo a revamp.