"Cool season grasses start growth at 5 °C", Wikipedia informs us. So embed cooling pipes under the lawn to keep the temperature at about 7-8 °C, thereby minimising the cutting requirements during the summer months. Why above 5 °C? It keeps your grass from looking brown and trampled, as it often does at the end of winter.
Use the energy extracted to heat your home, water etc (Thanks [TheNakedApiarist]). Note that heat pumps can run at coefficients of performance (efficiencies) of greater than 100%, creating more efficient home heating systems.
Of course, once your kids are old enough you can make them cut the grass as often as you like, saving you the electricity bills.
Just whatever you do, don't hollow tine aerate the lawn...-- TheLightsAreOnBut, Mar 14 2007 Lawn warming http://www.uponor.d...enheizung/index.phpLooks like the opposite of this is already baked [TheLightsAreOnBut, May 24 2007] If the under-soil pipes are infact the heat exchanger of your heat-pump based cetral heating, you can use the heat you draw from the soil to heat your home. heat heat heat heat heat. What a rubbish sentence, but you get the idea.-- theNakedApiarist, May 24 2007 Good idea, [Naked], amended with thanks.-- TheLightsAreOnBut, Jun 08 2007 random, halfbakery