@Gary ******
LTR-Visa's are preceded with a visa-endorsement letter from the BOI (issued via an agent if you use one), then you apply for the visa itself. We were outside Thailand when we applied so we used the E-visa method via the Thai-Embassy in Kuala Lumpur. We are renting for one year but if yours is shorter, you will need to test it with the bank. Certificate of Residence is issued by an immigration office, and for ours, they asked for passport, 4 x colour PP photos, rental agreement, copy of visa, complete their form, and pay 1,000THB.