Acorn offers custom designed houses as well as several standard design series, one of which is the Solar Series.
" . . . Acorn developed Sunwave (R) active solar systems, which have been installed in hundreds of Acorn houses since 1975."
" . . . In addition to active solar, we now offer a range of other techniques, including special insulation packages, strict control of air leakage, and passive solar design methods that take advantage of the sun's warmth at little or no added cost. "
"The Solar Series designs receive up to three quarters of their annual heating requirements from the sun."