4 Ground is/was a MDF building designer and seller. However, it seems the official closing date for them is June 30th 2022, going out of business.
https://www.4groundpublishing.co.uk/Although they said they were doing this because MDF pricing was increasing and pricing them out of the market, it seemed as if their pricing was getting a bit higher than other manufacturers anyway.
They are selling product on sale, so if your interested in picking up some, this will only be possible through June 30th 2022.