Your GHP contractor will be able to help you decide which configuration best meets your specific needs. Don't be afraid to ask for and use references. Reputable dealers and loop installers will be happy to give names and phone numbers for you to call and confirm their capabilities. Also, check with your utility company representative for names of installers. Research has shown that loops have no adverse effects on grass, trees, or shrubs.
Most horizontal installations require trenches about six inches wide.
Temporary bare areas can be restored with grass seed or sod. Vertical loops require little space and do not damage lawns significantly. My yard contains many shade trees. However, insulating and weatherizing are key factors in gaining the maximum amount of savings from any type of heating and cooling system. Many GHP systems are being installed using a multitude of systems hooked up to an array of buried vertical or horizontal loops.