 Under the Trust 's ownership the sawmill has been renovated and converted into a combined learning , educational and rentable function space for businesses and members of the public . It is most often used by National Trust staff and volunteers to educate visiting school groups . The building now houses the biomass boiler for the main house , which saves 141 tonnes of CO2 a year over the old oil @-@ fired boiler . Another section of the former wood shed was used as a new roost site for bat species , creating a " bat palace " . The centre was opened in May 2009 by Dame Jenny <unk> , Chair of the Heritage Lottery Fund , who partially funded the works . 
