Are S106 cotributions "eligible" expenditure for 1-4-1 receipts

We are now being charged s106 contributions for education and open spaces by the Council for council housing schemes. My question is, does anyone else do this and do you treat it as eligible expenditure for 1-4-1 purposes, ie 30% funded by 1-4-1 receipts. The cost will be incurred as part of the development so I think it meets the definition of an amount spent on the provision of social housing, but because it is new I'd be interested to hear others interpretations or experience with the auditors.