[7]: 17  The actual depth of the laboratory is 2,400 m (7,900 ft), yet there is horizontal access so equipment may be brought in by truck.

[21]: 239 A more difficult problem is that the walls of CJPL-I were lined with ordinary concrete taken from the hydroelectric project's supply.

The first phase was rapidly filled, and plans for a second were made quickly, before the excavation workers and equipment departed following completion of the hydroelectric project in 2014.

Totalling 210,000 m3 (7.4×10^6 cu ft),[24]: 4  and originally intended to be blocked off after construction,[23]: 20  they have been donated to the laboratory and will be used for support facilities.

CJPL has 93,300 m3[6][c] in the halls proper, and an additional 9,300 m3 in the shielding pits making a total of 102,600 m3, slightly more than LNGS's 95,100 m3.

[d] Including the service areas outside the main halls, the result is 200,000–300,000 m3 of usable space,[27]: 18 [23]: 22 [21]: 239  more than LNGS's grand total of 180,000 m3.

Thanks to the laboratory's location within a major hydroelectric facility, additional electrical power is readily available.

The muon flux in (and thus water equivalent depth of) CJPL-II is currently being measured,[23]: 25  and may differ slightly from CJPL-I, but it will certainly remain lower than SNOLAB in Canada and thus retain the record for the world's deepest laboratory as well.