And to further clarify my post, the return to dwellinghouse is important to prevent the D1 permission entitling the owner to make use of the space for other uses, including as a place of worship.

All houses in Lewisham are covered by the same planning rules designed to allow sensible use of property, rather than keeping all buildings stuck in the 1930s, when covenants were the only protection available to property developers and home owners. In fact if the owner wished to set up a doctor's surgery (which is an allowed profession according to the covenant), they would still require planning permission, and even the existing planning permission would not be good enough, despite both nurseries and surgeries being classed as D1.

And it would be extraordinary for a B6 business to be allowed in a residential area, even if it were producing vital chemical weapons capabilities.