Just to be clear, there's no such thing as a British accent. English/Scot/Irish/Welsh are all very different, within England theres about half a dozen distinct accents alone. The lad in the video is clearly from the south/west and speaking in embryonic pirate ! (and very bad example for ESOL )

As an English southerner who lived in London for a long time but now resides in the frozen north I can guarantee you get a multitude of different accents wherever you go in England. Depending on who it I am talking too most people in the North think I am either a cockney barrel boy or super posh because I say words like BATH as BaRth but not like the northern BAFF .
However the golden rule for words in English is they do not sound like they are spelt. So IDEA really is I-DEAR & AREA is AIR-REE-ARE.