Property sizes

[GertR]

Hi guys got a question please.

Preparing a application for a unmarried partner visa which will be dealt with via an attorney in London.
My questions is when it concerns providing evidence of the property we will be staying in in the UK after this application.
I rennovated this property complete refurbishment in 2016.
We been staying in the main bedroom 18sq meters big and the 2 other bedrooms I have been renting out.
How do I go about proving that this accommodation, the room my partner and I have been sleeping in for the last year or so are big enough and conform to the standards for this application.

Bought the property for around 100k and worth around 170k now but on the original listing of this property the agents never done a floor plan for it?
What is the way forward for me here?

Any input appreciated many thanks.

[seagul]

Best is to arrange property inspection report from the hands of qualified estate agent/surveyer.