When comparing stucco and vinyl siding, both are considered to be good when it comes to energy efficiency. Still, between the two options, stucco is more energy efficient. Stucco is made out of Portland cement and other materials, and it is essentially a thicker and denser compound. Stucco is generally cheaper to buy, and since it is more energy efficient, it can also potentially save you money on your heating and cooling bills, when compared with buying vinyl siding. Vinyl might be a little more durable and less susceptible to damage, but stucco is more energy efficient. Source: https://goo.gl/nNWj1u