Affordable Housing Scheme + Help to Buy

Hi All

I'm in the process of purchasing the new house through Affordable Housing Scheme run by City Council.

Local Authority Affordable Purchase Scheme (citizensinformation.ie)

My application has been approved for 2 bed property and I can use Help to Buy Scheme (application approved). Developer has sent me "Reservation Letter" with Open Market Value and Purchase Price of the offered property. Could you please advise which of those figures is taken into account for calculation of the deposit and Help to Buy relief? Is it 10% of Open Market Value or 10% of Purchase Price in the case of Affordable Housing Scheme?

I sent that query to Revenue more than 1 month ago and still haven't got clear answer which is very frustrating. Thanks

Tom