Lowkey tells us that "only 2% of the land in this country is built on at all" but he's off by a factor of about 5 times. l - figures available elsewhere show around 10% "built up", and 8.7% developed. (Figures are for England, obviously if you include Scotland and Wales, the figure will be less)

https://www.gov.uk/government/statistics/land-use-in-england-2022/land-use-statistics-england-2022#fn:2

37% Of land is protected from development. Agriculture is 63.1%, but that's land that feeds the population. Every percent of that land concreted over is a lot of food.

Now statistics can be difficult for anyone to accurately recall, but as it's an important point ( I suppose he's talking about housing?) it would be preferable he got this right.