development project in Virginia for a total investment of $26.4 million. This project is the second of a two-phase development by a consolidated joint venture in which the Company owns a 90% interest. As the two phases of the development are located adjacent to one another, they have been combined in our store count, as well as for operational and reporting purposes.
As of March 31, 2021, the Company had five joint venture development properties under construction. The Company anticipates investing a total of $120.5 million related to these projects and had invested $62.6 million of that total as of March 31, 2021. These stores are located in New York (2), Massachusetts (1), Pennsylvania (1) and Virginia (1). Subsequent to quarter end, the Company opened for operation one of the properties in New York and the property in Pennsylvania. The remaining three properties are expected to open at various times between the second quarter of 2021 and the second quarter of 2022.
Unconsolidated Real Estate Venture Activity
On March 17, 2021, the Company invested a 20% ownership position in HVP V, a newly formed unconsolidated real estate venture. In conjunction with its formation, HVP V acquired one store located in Florida for a purchase price of $14.0 million, of which the Company contributed $2.8 million.
During the first quarter of 2021 and through the date of this press release, the Company’s joint venture, HVP IV, acquired two properties located in Connecticut and Maryland for $35.5 million. Additionally, HVP IV has five properties under contract located in Illinois for $73.5 million that are expected to close during the second quarter of 2021.
Third-Party Management
As of March 31, 2021, the Company’s third-party management program included 701 stores totaling 46.8 million square feet. During the three months ended March 31, 2021, the Company added 31 stores to its third-party management platform.
Same-Store Results
The Company’s same-store portfolio at March 31, 2021 included 511 stores containing approximately 35.7 million rentable square feet, or approximately 92.3% of the aggregate rentable square feet of the Company’s 543 owned stores. These same-store properties represented approximately 90.7% of property NOI for the three months ended March 31, 2021.
Same-store physical occupancy as of March 31, 2021 and 2020 was 94.4% and 91.3%, respectively. Same-store revenues for the first quarter of 2021 increased 6.7% and same-store operating expenses increased 2.0% from the same quarter in 2020. Same-store NOI increased 8.9% from the first quarter of 2020 to the first quarter of 2021.
Operating Results
As of March 31, 2021, the Company’s total owned portfolio included 543 stores containing 38.7 million rentable square feet and had physical occupancy of 93.0%.
Revenues increased $24.8 million and property operating expenses increased $5.5 million in the first quarter of 2021, as compared to the same period in 2020. Increases in revenues were primarily attributable to revenues