303m2 is a large house (compared to the current average one 
In 1920, the average new large family home boasted five bedrooms and occupied 3,440 square feet. Today's equivalent has just four bedrooms and 2,409sq ft, while the ceiling height has dropped from 11ft to 8ft 8in.
A typical semi has gone from 1,647sq ft to 925sq ft, losing one of its four bedrooms.
Terraced houses have shrunk from three bedrooms and 1,020sq ft to two bedrooms and 645sq ft.)
Your biggest challenge with GSHP will be the collector loops, assuming horizontal loops (NOT Slinkies, they can cause big problems and are too often undersized) you will need a large field to cope with the heating requirment and it will make a mess of it, and will have a fair bit of spoil to level out, alternatively boreholes may work out cheaper at that size.
Have you done the full house heat load calcs yet? If its up for sale at the moment a recent EPC will quote an estimated annual kWh heating demand (we reckon on larger properties these are about 30% under what they should be...) this form is a good start: Domestic heating sizing method (2010 edition) / Heating systems / Housing professionals / Publications / Home (England) - Energy Saving Trust England - though it can't be used for the detailed design/contract stage (that must be room by room)
In 1920, the average new large family home boasted five bedrooms and occupied 3,440 square feet. Today's equivalent has just four bedrooms and 2,409sq ft, while the ceiling height has dropped from 11ft to 8ft 8in.A typical semi has gone from 1,647sq ft to 925sq ft, losing one of its four bedrooms.
Terraced houses have shrunk from three bedrooms and 1,020sq ft to two bedrooms and 645sq ft.)
Your biggest challenge with GSHP will be the collector loops, assuming horizontal loops (NOT Slinkies, they can cause big problems and are too often undersized) you will need a large field to cope with the heating requirment and it will make a mess of it, and will have a fair bit of spoil to level out, alternatively boreholes may work out cheaper at that size.
Have you done the full house heat load calcs yet? If its up for sale at the moment a recent EPC will quote an estimated annual kWh heating demand (we reckon on larger properties these are about 30% under what they should be...) this form is a good start: Domestic heating sizing method (2010 edition) / Heating systems / Housing professionals / Publications / Home (England) - Energy Saving Trust England - though it can't be used for the detailed design/contract stage (that must be room by room)
