thermal hole: An opening such as a window that leaks heat and air-conditioning energy.

thermal mass : The ability of a material to absorb and store temperature.

three Rs: The environmental practices of reducing consumption, reusing items, and recycling.

top-dressing : Applying a light scattering of compost, other mulch, or sometimes fertilizer, over soil surfaces to add organic matter or nutrients without digging it in

toxic waste: Disposed materials that can cause harm to people, animals, or the environment.