Now Morling's employees can hold meetings in the "chalet", "library" or the "ice cave" and have use of a Star Trek cinema, arcade room and Rolling Stones-themed toilets.
At the heart of the 10,000 sq ft 'office' is playfulness, creativity - and plenty of orange paint.
As Llewelyn-Bowen put it: "It is like being hit round the face with a dirty, great big tube of Berocca."
Morling said the idea behind the project was to 'make a great place for people to work'. "It is about making this a wonderful place, a productive place to work," he said. "What we have done is modelled all the design around the needs of the team.
"Some people want to stand while they work, some people to work alone. Ultimately it boils down to creating a space where you feel comfortable."
In seven years money.co.uk has gone from having a workforce of seven to 50 - although Morling continues to interview every candidate and remains invested in each individual.
At the start of the 14-month project the entrepreneur asked each employee what was missing from their current office. He also commissioned design firm Interaction and TV designer Laurence Llewelyn-Bowen.
Looking after your team is paramount and it's really important I give them the best of everything. Ultimately my team are my most valuable asset.
Morling explained he brought the famously flamboyant designer on board - the men were introduced through their personal trainer - because he needed someone who could "think outside the box". Llewelyn-Bowen saw the project as a chance to re-imagine the 'ugly, unfriendly and un-creative' interiors of the modern workplace.
From there it was a case of ticking off the employee wishlist - from coffee machines to standing desks.
Morling said: "Looking after your team is paramount and it's really important I give them the best of everything. Ultimately my team are my most valuable asset."
The result is a breathtaking combination of colour, eccentricity, and state-of-the art technology.
Employees walk up the imposing steps of the castle into a reception space whose walls are planted with lush green foliage. "A very, very nurturing Narnia," Llewelyn-Bowen said, adding: "And Chris is Mr Tumnus!"
During the consultation process staff asked to be given spaces of varying sizes and their wishes were granted. They now have the choice of airy open planned rooms or cosy nooks that are perfect for working alone.
The design also places an emphasis on humour and social interaction, with popcorn machines, table football and the Star Wars cinema all adding to the sense of play.
Eight years on, I'm lucky enough to have built a team of 50 best in class individuals... In the next year, my search for the kings and queens of tech will be ongoing as I plan to grow my team by a further 20 per cent.
While such a bold renovation might seem to sit in opposition with its historic surrounds, a huge amount of time and money also went into "not only preserving this building but also augmenting it," Llewelyn-Bowen said.
Morling - whose favourite room is the stylish 'Steam Punk' men's lavatory - said the response from his employees has been 'universally positive'.
And it is perhaps just as well given the entrepreneur's ambition to create "the best place to work". The commitment to his employees is even more essential given Mr Morling's decision to base the company outside of London.
He added: "When I first decided to build my business outside of London I knew recruitment was going to be tricky.
"Eight years on, I'm lucky enough to have built a team of 50 best in class individuals... In the next year, my search for the kings and queens of tech will be ongoing as I plan to grow my team by a further 20 per cent."
The castle might seem like an extravagant base for still a relatively modest company but Morling insists it is a 'really cost effective choice if you compare it to 10,000 square foot of space in London.'
However even with the flat screen TVs, SONOS sound system and hamster murals, the castle remains the "icing on the cake", according to Mr Morling.
He explained: "An amazing physical environment is just a small piece of the jigsaw when you're creating a great place to work.
"When your team truly feel valued and their opinions are listened to they feel empowered and that's worth far more than any of the perks and benefits we offer."
Although the 'perks and benefits' go far further than free cups of tea or discount at the local cinema. money.co.uk employees can take advantage of a free onsite gym, yoga studio and flexible working hours.
And for the days when they are feeling a little less motivated, they also have access to pool tables, a PS4 and free beers. Once a month there are lunchtime and evening socials - paid for, of course - and games of football and basketball are organised every week.
Staff who perform well can also receive up to 45 per cent in an annual bonus. Each employee is offered an annual all inclusive mini break abroad to destinations such as Florida, New York, Budapest, Dubrovnik and Copenhagen.
Morling added: "When employees truly believe they are valued and their opinions count they feel empowered and productivity becomes limitless."
