En bloc is known as a collective sale, a sale of two or more property units to a single common purchaser. At least 80% of its residents must agree to sell their home for the deal to proceed.
In my opinion however, it is very easy for en bloc collective sales to fail if it is not at the right price. You need to find an excellent consultancy, understand the price that you’ll get, the correct pricing for your tender. It is better to be realistic and get the right pricing and be successful, rather than putting in all the effort and the price proposed was too high.