The Newtown Board of Selectmen has signed off on a plan to modernize ventilation and air conditioning at Hawley School.  But the proposed upgrades require the 100 year old school building to be closed for a year.  The 280 students would be sent to Sandy Hook and Reed Intermediate Schools next academic year while work is done at the old brick building on Church Hill Road.  The cost for the work is expected to be $7.8 million and needs approval from residents in a referendum this November.  If approved, Newtown officials will have to decide if federal pandemic relief funding could and should be used to offset the cost.  The Selectmen sent the proposal to the Board of Finance last night for further consideration.