Same-Store Communities
Our Same-Store Community properties, those acquired, developed, and stabilized prior to July 1, 2021 (for quarter-to-date comparison) and January 1, 2021 (for year-to-date comparison) and held on September 30, 2022 consisted of 50,318 and 47,344 apartment homes and provided 92.7% and 90.2% of our total NOI for the three and nine months ended September 30, 2022, respectively.
Three Months Ended September 30, 2022 vs. Three Months Ended September 30, 2021
NOI for our Same-Store Community properties increased 14.6%, or $31.2 million, for the three months ended September 30, 2022 compared to the same period in 2021. The increase in property NOI was attributable to a 12.2%, or $38.7 million, increase in property rental income, partially offset by a 7.2%, or $7.5 million, increase in operating expenses. The increase in property rental income was primarily driven by an 11.5%, or $34.4 million, increase in rental rates, a $6.1 million decrease in rent concessions and a 10.8%, or $3.9 million, increase in reimbursement and ancillary and fee income, partially offset by a $2.8 million increase in occupancy loss. Weighted average physical occupancy decreased by 0.7% to 96.8% and total monthly income per occupied home increased by 13.0% to $2,446.
The increase in operating expenses was primarily driven by a 12.1%, or $2.4 million, increase in repair and maintenance expense due to the increased use of third party vendors as a result of an increase in the number of homes that turned as well as the impact of inflation on those third party vendor costs, a 20.2%, or $1.1 million, increase in insurance expense due to increased claims, a 5.2%, or $2.2 million, increase in real estate taxes due to higher assessed valuations and a 9.8%, or $1.4 million, increase in utilities, which was primarily due an increase in energy costs.
The operating margin (property net operating income divided by property rental income) was 68.7% and 67.3% for the three months ended September 30, 2022 and 2021, respectively.
Nine Months Ended September 30, 2022 vs. Nine Months Ended September 30, 2021
NOI for our Same-Store Community properties increased 14.3%, or $86.3 million, for the nine months ended September 30, 2022 compared to the same period in 2021. The increase in property NOI was attributable to an 11.4%, or $101.3 million, increase in property rental income, partially offset by a 5.3%, or $15.0 million, increase in operating expenses. The increase in property rental income was primarily driven by an 8.4%, or $71.7 million, increase in rental rates, a $1.2 million decrease in our bad debt expense related to multifamily tenant lease receivables, an $18.6 million decrease in rent concessions, a $1.5 million decrease in occupancy loss and a 10.9%, or $10.7 million, increase in reimbursement and ancillary and fee income. Weighted average physical occupancy increased by 0.2% to 97.1% and total monthly income per occupied home increased by 11.2% to $2,394.
The increase in operating expenses was primarily driven by a 12.5%, or $6.2 million, increase in repair and maintenance expense due to the increased use of third party vendors as a result of an increase in the number of homes that turned as well as the impact of inflation on those third party vendor costs, a 27.7%, or $4.0 million, increase in insurance expense due to increased claims, an 8.1%, or $3.1 million, increase in utilities, which was primarily due an increase in energy costs, and a 2.0%, or $2.4 million, increase in real estate taxes due to higher assessed valuations.
The operating margin (property net operating income divided by property rental income) was 69.6% and 67.8% for the nine months ended September 30, 2022 and 2021, respectively.
Non-Mature Communities/Other
UDR’s Non-Mature Communities/Other represent those communities that do not meet the criteria to be included in Same-Store Communities, which include communities recently developed or acquired, redevelopment properties, sold or held for disposition properties, and non-apartment components of mixed use properties.
Three Months Ended September 30, 2022 vs. Three Months Ended September 30, 2021
The remaining 7.3%, or $19.3 million, of our total NOI during the three months ended September 30, 2022 was generated from our Non-Mature Communities/Other. NOI from Non-Mature Communities/Other increased by 284.9%, or $14.3 million, for the three months ended September 30, 2022 as compared to the same period in 2021. The increase was