DIY SOS started as a low budget TV show where a presenter (Nick Knowles) and a small team of builders and a designer would come to the rescue of a home owner that'd started a Do It Yourself renovation, but was unable to finish it for various reasons. It degenerated into almost a parody of itself, featuring more about the builders antics than the actual building or repair work.
Then it evolved.
It became DIY SOS The Big Build. This is a totally different beast.
The same presenter, and the same core of builders suddenly became the heart of a much bigger and important venture. Each episode, a deserving family, due to illness or disability, would have their home renovated to make their lives a little easier. Whether it's making the house wheelchair accessible, or a complete internal rebuild, local trades and builders giving their free time would descend and transform the house in 9 days, to give hope to the owners of a better, or at least a less terrible future. The amount of good will displayed by ordinary people is heart warming in these often self-centred times, and makes for an uplifting TV programme.