In Hong Kong cremation is virtually enforced - there isn't enough land for burial. Government cemeteries allow a burial for 7 years - at the 7th year the remains are exhumed and cremated and "re-buried".
The Catholic church of Hong Kong doesn't offer burials now - all new "burials" in Catholic cemeteries are for cremated bodies. The only place I can think of that offers permanent burials are at some of the "Chinese Permanent Cemeteries" owned by non-profit public organizations. Typically, a permanent burial ground costs around HK$150,000 - ie US$19,230 which is beyond the reach of most HK Chinese, and very often applications for permanent burial spaces are turned down even if you have the fund to buy such ground. I wonder how Catholics in the West will respond in such case?
In the past, we have done so by periodically exhuming old graves and placing old bones (if any are found) in an ossuarium. This practice dates at least to medieval times.