Kirstin
Stone is the best for insulation, lowering your electricity costs. Anything wood I would use bamboo.

Bertybign
Here is a list of sujects that you should research on the internet which will provide a comprehensive answer: 1. Double glazing will creat a near vacuum that is an excelelnt insulator from heat loss (or gain) by convection or conduction. A special coating on the outside surface will also reduce gain through radiation 2. A cavity between the internal and external walls filled with insulating materials will cut down loss through the walls. This material should be made with a fibre with high resistance to conductivity and have a reflective (shiney silver) coating form aluminium on one side. Walls can be wood or brick/stone 3. Floors should be suspended from the earth but lined underneath by similar insulation materials to the walls. 4. Roof should have plastic lining that prevents draughts and then a fibre insulation underneath also with reflective coating. 5. Clay tiles or metal roof is fine. 6. Doors should have effective draught excluders to prevent heat loss this way. 7. add a heat pump system that extracts heat from atmosphere outside and upgrades it to provide background heating in loops located underneath your flooring. This is also reverseable in Summer to provide cooling. 8. Heating should be electrical using low cost power at night or if gas then a condensing boiler shoudl be used that extarct maximum heat from combustion. 9. Solar heating panels on roof can pre-heat water 10 small wind turbine can cut down on power 11. Use low energy light bulbs 12. always cook with lid on pots 13. Use showers and not baths for washing 14 Separate waste water from sewage and save for watering garden 15. have toilets that flush small amounts for Urine and larger amounts for larger objects 16 collect rainwater from roof and store for other uses 17 Hetaing should be thermostatically controlled for effficiency 18 If you liove in a very cold country then facing South Helps. If a hot country then facing East ensures heat in mornings 19. If you want something unusual the try a micro gasifier heating system that exports excess energy to power on the grid but otherwise you create your own heat and power in a CHP unit 20 consider buring waste packaging and wood in a multi product stove located in your main living are with balanced flue so that you do not suck air in from outside I hope that this helps Good Luck