In a recent tweet, Elon Musk reiterated his plan to use dirt from The Boring Company’s tunnels to create bricks that can be used in the construction of low-cost houses.

The Tesla CEO’s latest update on the Boring Company bricks was posted on Monday as a response to Cody Johnston, a Twitter user who asked Musk if he would like to get into the affordable housing industry. Responding to Johnston, Musk stated that the Boring Company would be up for the task.

The Boring Company will be using dirt from tunnel digging to create bricks for low cost housing — Elon Musk (@elonmusk) May 7, 2018

The Boring Co. bricks were first mentioned by Elon Musk back in March. In a series of tweets, Musk stated that the tunneling startup would soon release the blocks as its next merchandise, following the Hat and the Boring Company (Not A) Flamethrower. According to Musk, the life-sized LEGO-like interlocking bricks would be made from tunneling rock, which would be rated for California seismic loads but bored in the middle to save on weight.

Musk further noted that the interlocking bricks could be used to create “sculptures and buildings,” that would be sold in the form of “kits.” Musk also joked that the bricks would be 100% flamethrower-proof.

It did not take long before one of Elon Musk’s followers asked if the blocks could be used to build affordable houses. Musk responded to the suggestion in the affirmative, stating that the Boring Bricks are “interlocking with a precise surface finish,” which would allow the blocks to be stacked without compromising durability. Musk even noted that with the Boring Bricks, “two people could build the outer walls of a small house in a day or so.”

Among the Boring Company’s merchandise, the Bricks appear to be one that has been in the pipelines for some time. As could be seen in the tunneling startup’s FAQ page, the company is planning on recycling dirt from its excavated tunnels. The recycled dirt would be used to form blocks, which would, in turn, be used as tunnel linings or as building materials for structures like houses.

“The Boring Company is investigating technologies that will recycle the earth into useful bricks to be used to build structures. This is not a new concept, as buildings have been constructed from Earth for thousands of years including, according to recent evidence, the Pyramids. These bricks can potentially be used as a portion of the tunnel lining itself, which is typically built from concrete.”

The Boring Company is making headway into its tunneling operations lately. Last April, an LA City Council Public Works Committee awarded the startup with an exemption from environmental review under the California Environmental Quality Act (CEQA), for its proposed 2.7-mile proof-of-concept tunnel under Sepulveda Boulevard in West LA and Culver City.