Cracks below Bay window, subsidence problem?

bytecho

Hi,
I am buying a 1930's house in South East London, the RICS building survey report says below:

"There is further cracking below the sill to the front bay window and there is evidence of movement to the tile creasing sill detail. Again, an inspection of the brickwork was not possible given the roughcast render. However, this cracking also appears to be structural albeit this is of a slightly different nature. The pattern of the cracking again is through 35 degrees and is more suggestive of some movement to the bay window. The suggestion from the cracking is that the bay has potentially moved down to the left hand side and has partially subsided."

I understand that cracks around Bay window are not uncommon due to shallow foundations. I have also got a quote from a builder who suggested that the cracks are related to the brickworks not just the render. As the stamp duty stamp is near, we have no time to appoint a structural engineer to look at this. Even we can get hold of a SE, I doubt the vendor will allow us to open up the render to investigate the problem.
I have attached the photo, can anyone advise whether the cracks are common and fixable, and will not affect future resale? I am about to ask for a price reduction, but if it is real subsidence, I might have to walk away.

greenface2

Builder must be guessing its related to the brickwork . TBF I can only just see the crack above and not really the one below . ould be shrinkage . could be historical (could be new and foundation problem .) 

stuart45

Are you sure it's brickwork over the bay. Nowadays Catnic and others produce special lintels to take a cavity wall over a bay, but back then if brickwork was used it was normally a single skin on top of a strong timber bay window. It was more common to use a timber frame and render or tile hang it. Getting the right support for brickwork over that bay would not be easy when replaced with a plastic frame, unless a special lintel and supports were used.