It appears to be an ordinary house, so why all the barbed wire around it? The other side of the fence is the grounds of Buckingham Palace. I guess the ordinary house is actually a guards house or something similar. The grounds are usually off limits to the public, however when the Queen is away during summer (August and September) and the palace is open to the public, visitors also have access to part of the garden and can buy an ice-cream made especially for the occasion.
