The search for Britain's best amateur interior designers begins with the first of eight heats. Would-be interior designers Sarah, Helen and James take on three large bedrooms in Edwardian homes in the leafy north London district of Muswell Hill. They have 48 hours, £1000 and the help of a builder to interpret and make real the homeowners' briefs. Vintage homeware designer Sarah has given herself a lot to do including upholstering a chair, something she has never done before. Asset manager James has to get the homeowners on-board with his bright colours and artist Helen is hoping to discover an Edwardian gem behind some built-in cupboards. As well as impressing the homeowners, they must also satisfy judges Sophie Robinson and Daniel Hopwood. Only one designer can make it through to the quarter final.

In the second of eight heats, three more designers battle it out for a place in the quarter final, this time taking on three knocked-through sitting rooms in neighbouring homes in a terrace in Salford. Architectural historian Tom Dyckoff discovers the history of the homes and the workers they were built for, as judges Sophie and Daniel decide who has the winning design. 65-year-old housewife Susan is hoping her paint effects will win favour, while financial lawyer Nigel is banking on some funky wall transfers. Meanwhile, mum Lynne faces hard work persuading the homeowner that her ideas will work. With upcycling challenges and schemes to pull together the designers have got to convince everyone that they have what it takes to be an interior designer. With only 48 hours, £1000 and the help of a builder, there is a lot to do and only one designer will be able go through to the quarter finals.

It is the third of the eight heats as three more designers battle it out for a place in the quarter-final. This time the amateurs are taking on very unusual and rather beautiful homes in Beckenham, Kent. Built in the 1930s, these homes are classic art deco design - blocky, bright white with a touch of Hollywood glamour. The amateurs are asked to redesign sun rooms at the very top of the houses. Surrounded by glass, they create a unique challenge for the designers. Executive assistant Louise hopes her 1930s cocktail bar will do the trick, while student Charmaine wants to win with her office design. Artist Amy is going all out with her Miami beach theme but with the homeowners being happy with the design being a crucial part of the criterion for winning, will she be able to convince them that gold and purple are the colours to go for? With only 48 hours, £1000 and the help of a builder there is a lot to do and only one designer will be able go through to the quarter finals. Architectural Historian Tom Dyckoff discovers the history of the homes and the influences of art deco, as Judges Sophie and Daniel decide who has the winning design.

In the fourth heat, the amateurs are in south east London on the River Thames, taking on sitting rooms in neighbouring homes in a beautiful converted mill. Architectural historian Tom Dyckhoff discovers the history of the mill and the local area, as judges Sophie and Daniel decide who has the winning design. 55-year-old housewife Dee, from Whitstable in Kent, is hoping her French farmhouse style will win the day, but finds resistance from her client. 40-year-old vintage enthusiast Emma from Manchester is also working hard to persuade her client on aspects of her boat house theme. 30 year old shop worker Luke from Oxford is keeping his client happy by turning his creative skills on making cat furniture for his African themed room. With upcycling challenges and tricky clients the designers have got to convince everyone that they have what it takes to be an interior designer. With only 48 hours, £1000 and the help of a builder there is a lot to do and only one designer will be able go through to the quarter finals.

It is the fifth of the eight heats as three new designers battle it out for a place in the quarter-final. This time the amateurs are taking on the toughest of makeovers - three kitchens. They will be painting, tiling and creating their own designs in three 1960s homes in an estate in Ashstead, Surrey. With only 48 hours, £1000 and the help of a builder, the amateur designers need to manage their budgets and homeowner expectations if they are to get their schemes finished on time. 24-year-old young mum Kimberly from Bicester in Oxfordshire has the added pressure of having to fit appliances recently purchased by her homeowners into her scheme for a bright 60s kitchen. 54-year-old housewife Anna from Chigwell has concerns over tiling her shaker kitchen, while 39-year-old Julia from Nottingham needs a steady hand to transform a dark shiny kitchen from black to white. There is a lot to do and only one designer will be able go through to the quarter-finals. Architectural Historian Tom Dyckhoff discovers the history of these unique Span Developments homes and the architect behind the utopian vision of his estate, as judges Sophie and Daniel decide who has the winning design.

It's the sixth of the eight heats as three new designers battle it out for a place in the quarter-final. This time the amateurs are creating interiors for three beautiful Georgian almshouses in Southwark, London. They will have 48 hours, £1000 and the help of a builder to turn three sitting rooms into modern designs fit for the inhabitants of these 250-year-old homes. 42-year-old retail manager Neil from Brighton has a relaxed approach that sees him create a bicycle-themed sitting room. Events coordinator, 36-year-old Jane from Kent, is organised and on time to get her Moroccan-themed room finished, until she's asked to deliver some storage space; and mum Lorna from Birmingham, has to deliver a Casablanca style sitting room, but is she trying to deliver too many ideas? Architectural historian Tom Dyckhoff discovers the history of the almshouses, as judges Sophie and Daniel decide who has the winning design. With upcycling challenges, late deliveries and expectations high, only one can go through to the quarter finals.

It's the penultimate of the eight heats as three more designers fight it out for one of the last places in the quarter-finals. This time the programme has travelled to Berrylands in the heart of London's suburbia. The owners of these classic semi-detached 1930s homes are hoping the three amateur designers will bring new life and vigour to their front sitting rooms. Architectural historian Tom Dyckhoff discovers the history of the homes and the circumstances that led to their build. Judges Sophie Robinson and Daniel Hopwood will be looking to see who as the potential to go through to the next round. Pub landlady, 43-year-old Paula from Herefordshire, is more used to doing up the interiors in the pubs she and her husband have lived in over the years. Creating an interior for someone else proves a real test of her confidence as she has to make the decisions on colour, fabric and built-in storage for the homeowner, and hope she is getting it right. 40-year-old textile designer Helen from Devon finds she has to confer with her owner nearly every step of the way before finally being allowed to create her South African-themed scheme. The third contestant is 44-year-old painter and decorator Johnny, he's used to doing the work on other people's design ideas and now he's got to create and pitch his own; but keen to prove he is more than just a decorator his complicated shelving scheme might be over ambitious. But only one can go through to the quarter-finals and this time Sophie and Daniel are finding it particularly hard to choose.

t's the last of the eight heats as three new designers battle it out for the last place in the quarter-final and the chance to win The Great Interior Design Challenge. This time the amateurs are taking on three vast living rooms in Brighton. Architectural historian Tom Dyckhoff explores the history of the homes and the Regency period, as judges Sophie Robinson and Daniel Hopwood decide who has the winning design. The amateurs are 30-year-old café owner Jordon from South London, 37-year-old mum Alice from Lewes in Sussex, and 44-year-old business woman Jenny from Cornwall. Jordon demonstrates his showmanship with his take on Hollywood glamour; Alice creates a fun room with zones for all the family; and Jenny goes for a rustic French country kitchen scheme. But with only 48 hours, £1,000 and one of the largest rooms yet, there's a lot to do and only one designer will be able go through to the quarter-finals. For Daniel and Sophie, with such varied designs to choose from, and everyone rising to the upcycling challenge, it's a tough choice to make.

It's the first quarter-final and four of the winners from the previous eight heats are now ready to paint, sew and build their way to a gain the first two places in the semi-final of the The Great Interior Design Challenge. This time the amateurs are taking on four thatch cottages in Milton Abbas, Dorset. Having won a heat already, confidence is running high for all the amateurs, but they have to prove they have versatility and new ideas. Architectural historian Tom Dyckhoff explains the fascinating history of this Georgian 'model village', built in 1779. Judges Sophie Robinson and Daniel Hopwood judge which two of the four amateurs are good enough to go through to the semi-final, and they won't be so lenient this time if contestants are running late or the rooms are unfinished. The amateurs each have 48 hours, £1,000 and the help of a builder, but only two of the designers will be able go through to the semi-final.

It's the second quarter-final and four more winners from the previous eight heats are now ready to paint, sew and build their way to win the last two places in the semi-final of the The Great Interior Design Challenge. This time the amateurs are being challenged to redesign four compact bedrooms in a 1950s brutalist tower block in Bethnal Green, East London. The spaces are smaller, but it makes the challenge tougher. Designed by the architect Denis Lasdon who also designed the South Bank, architectural historian Tom Dyckhoff looks at the history of the block and how it was rescued from demolition to become one of the more desirable places to live in East London. While Judges Sophie Robinson and Daniel Hopwood cast their eyes over the various designs to see who is most deserving to go through to the semi-final.

It is the semi-final and the four winning interior designers from the quarter-finals fight it out for the two places in the final and the chance to win the Great Interior Design Challenge. This time the amateurs take on four enormous front rooms in beautiful Arts and Crafts Victorian houses in Moseley, Birmingham. Architectural historian Tom Dyckhoff uncovers the history of the homes and the Arts and Crafts movement, as judges Sophie Robinson and Daniel Hopwood decide which two interior designers will be going through to the grand final. The contestants still only have 48 hours, but the money has gone up to £1,500, so the expectations are higher.

It is the final of the Great Interior Design Challenge, and after starting with 24 amateur interior designers, it is down to the last two. This time the stakes are raised as each amateur interior designer is given a grand Georgian house where they must redesign the hallway, front room, guest room and a child's bedroom. It is a huge undertaking. The money has gone up to £4,400 and they now have 72 hours, the help of two builders and a decorator. Architectural historian Tom Dyckhoff reveals the history of these beautiful Liverpool homes. Daniel Hopwood and Sophie Robinson must judge who deserves to win - but it is a tough decision as there are very different designs on offer.