... din experienta ...
prima varianta este o traducere a termenului ("neologism" preluat gresit, de altfel; parerea mea) iar a doua varianta este sintagma uzuala in domeniu

to envelop = to wrap up in or as in a covering:

A building envelope is the separation between the interior and the exterior environments of a building. It serves as the outer shell to protect the indoor environment as well as to facilitate its climate control. Building envelope design is a specialized area of architectural and engineering practice that draws from all areas of building science and indoor climate control.
http://en.wikipedia.org/wiki/Building_envelope

The building envelope is the outer layer of the building that separates the living space from the outdoor environment, both above and below grade. Many older homes have high heating requirements because of high rates of air leakage and building envelope areas that are not well insulated.
http://www.cmhc-schl.gc.ca/en/co/renoho/refash/refash_007.cf...