Cavity Wall Insulation

I don't think you even need a loophole. Put up a (cheap) fence between the two properties if necessary.

It already has a letterbox, jingl.

It used to be business premises so has always been treated as a separate entity. You're right, it is a rubbish decision and one that's worth a fight.

It's been de-registered with the council so we no longer pay business rates.....There must be a loophole somewhere

It's the post office you need to approach. They are responsible for addresses of properties. If the mail for the annexe is being delivered to the annexe and the mail for the farm is being delivered to the farm, then they are separate properties.

Give the annexe a name, and a letterbox. Do not accept this rubbish decision.

One of the conditions of the planning permission is that the two properties are treated as one - so it can't be sold off separately. They are really strict about this on green belt land. Our bungalow doesn't have cavity wall insulation because it's old and has a solid wall but obviously the new building has to have it to meet planning regs so why no grant for insulation?

I won't give up just yet. Makes me cross when we're actually doing what the government wants us to do which is freeing up a dwelling for a family and hopefully not becoming a burden on the state when we need someone to keep an eye on us as DD will be living next door.

I suggested to the man from WarmFront that we give it a different number to the main dwelling - which doesn't have one because it's a farm address - and he said, 'That won't wash!'

Do you pay council tax separately from the main property, merlot?

Could you get a separate address for it? Even just adding 'a' and 'b' perhaps? Does it have a separate letterbox? You could try getting onto the post office.