Modernizing air-conditioning in a 75,000-square-foot building built decades before the widespread adoption of central air, cleaning up and restoring murals, terracotta tiles and decorative flooring and enhancing garden areas are top goals for the two-year renovation project for the Church of Jesus Christ of Latter-Day Saints’ Mesa Arizona Temple.

The Mesa temple will close May 19 and won’t reopen until 2020. The Mormon church has hired Salt Lake City architecture firm GSBS Architects to handle the designs and Gilbert’s Porter Brothers Inc. as the contractor for the project.

The renovations also include some needed repairs and upgrades, said Emily Utt, historic sites curator.

“We need to get the air conditioning back a little better,” Utt said. “We need to get the plumbing fixed.”

The Mesa temple opened in 1927 and its ventilation systems were originally constructed well before implementation of central air conditioning.

Bill Williams, director of temple design for the LDS Church, said the Mesa temple was originally built with a system of ventilation tunnels that aimed to move air about the building.

“In 1920 that was a good idea,” Williams said.

The temple get new HVAC systems aimed at cooling the structure better, Williams said.

Murals, terracotta and tile flooring in the temple, which is only open to LDS members, will get cleaned up and restored. Garden areas will be upgraded as well a reflecting pool in front of the Mormon temple.

The church is also tearing down the existing visitors center building in front of the Mesa Temple and building a new one at the corner of Main and LeSuer streets. That new building — which will include a new ancestry research center — and the temple’s gardens will be open to the public.

The LDS Church will hold an open house to general public (including non-church members) when the renovations are completed.

Church officials declined to disclose a cost estimate for the temple project.

The church has also acquired some properties adjacent to the temple near Main Street and Mesa Drive and will soon announce those development plans.