The objective of Artis' organic growth strategy is to identify and extract the maximum value from each asset in its portfolio. The key to achieving this objective is efficient and effective management of assets, maintaining high occupancy levels, capitalizing on increases in renewal rents and realizing the gain between in-place or expiring rental rates and market rental rates through leasing activities.
During 2018, Artis' management team successfully renewed 1.7 million square feet of gross leasable area, reporting a weighted-average increase in renewal rents of 2.3%. This demonstrates a healthy rate of organic growth. In addition to the increase in renewal rents achieved, Artis reported that stabilized same property net operating income (which excludes the Calgary office portfolio and properties planned for disposition or repurposing), increased by 2.9% year-over-year, and increased 1.1% year-over-year when calculated inclusive of the Calgary office portfolio and properties planned for disposition or repurposing. Management estimates market rents are 1.3% above in-place rents across the portfolio (or 1.8% above in-place rents when calculated exclusive of the Calgary office portfolio). These metrics are indicative of potential revenue growth to be gained from future leasing activities.
Development projects are an integral part of Artis' new initiatives announced in November and are an important component of Artis' growth strategy. With capitalization rate compression in many of Artis' target markets and, therefore, fewer compelling opportunities to acquire real estate, value creation through development and redevelopment projects present a way to achieve growth at attractive yields. New development projects also increase the overall quality and leasable area of Artis' portfolio, which correspondingly increases revenue potential and asset value. Value creation projects improve the aesthetics of Artis' assets, while simultaneously increasing the energy efficiency and revenue growth potential of its buildings.
Artis completed two new development projects in 2018: 169 Inverness Drive West I and Park Lucero IV.
169 Inverness Drive West I is an office development in the Greater Denver Area, Colorado, situated on a 10-acre parcel of land adjacent to the AT&T Building, an office building acquired by Artis in 2013. The first phase of this multi-phase project includes a Class A office building totalling approximately 118,000 square feet of leasable area. The site is located on the I-25 with immediate connectivity to the light rail transit system.
Park Lucero is a four-phase industrial development on a 48-acre parcel of land in the Greater Phoenix Area, Arizona. The first phase of this project was substantially complete in 2015 and consists of three state-of-theart industrial buildings totalling approximately 208,000 square feet of leasable area. Construction of the second and third phases, comprising approximately 132,000 and 147,000 square feet of leasable area, respectively, were completed in 2017, while construction of the fourth phase, comprising 96,000 square feet of leasable area, was completed in 2018. All phases of the development total approximately 583,000 square feet of leasable area and are 100% leased.
Artis has numerous ongoing development and densification projects underway in the portfolio. In 2018, construction of 300 Main and 330 Main began, which are two new projects that will span nearly an entire city block in downtown Winnipeg, Manitoba. These sites are located above the Shops of Winnipeg Square retail concourse and Winnipeg Square Parkade, and adjacent to 360 Main, a 30-storey Class A office tower, all of which is currently owned by Artis. 300 Main will be a best-in-class amenity-rich apartment building with main floor commercial space, while 330 Main will be a state-of-the-art multi-tenant retail property. 330 Main is approximately 90.0% leased pursuant to a 20-year lease with rental increases every five years. At Park 8Ninety in the Greater Houston Area, Texas, the first phase is complete and 88.5% leased, while construction of the second phase is under way and 40% pre-leased. Artis successfully negotiated a build-to-suit development for the third phase at the site with a national tenant for 33,000 square feet that is expected to be complete in mid-2019.
During 2018, Artis acquired three parcels of development land in the U.S., including Cedar Port, Tower Business Center (80% interest in the form of a joint venture arrangement), and 1630 Aspen. Cedar Port is a two-phase development expected to comprise approximately 1.0 million square feet of industrial real estate in Houston, Texas. Construction of the first phase of this project has commenced and will total 519,000 square feet, which is 100% leased for a 12.5-year term. Tower Business Center is a two-building industrial development in the Greater Denver Area, Colorado, that is expected to total approximately 420,000 square feet. Construction is underway, and there has been positive leasing interest in this development. Last, 1630 Aspen is a parcel of land adjacent to an owned office property in Madison, Wisconsin, that will be held for future development.
Value creation can also be achieved through the redevelopment of existing assets within the portfolio, by capitalizing on opportunities to realize the highest and best use for a property or by modernization to attract long-term credible tenants and remain competitive in the marketplace. Artis' management conducts ongoing strategic review of each asset in its portfolio to identify such opportunities. At the end of 2018, Artis had two properties held for redevelopment; Sierra Place, an office asset in Calgary, Alberta, and 2145-2155 Dunwin Drive, an industrial property in the Greater Toronto Area, Ontario. Sierra Place is undergoing an extensive redevelopment to be converted from an office to a residential property. Sierra Place, which is conveniently located downtown on a light rail transit line and provides access to the city's Plus 15 walkway system, will have approximately 100 suites upon completion of the redevelopment. 2145-2155 Dunwin Drive is being converted into commercial condominium units.
In addition to the above noted projects, Artis has an extensive development pipeline, which consists of commercial projects that are in the early planning stages to be developed over the next several years and projects that are being considered for future development. The REIT also has several potential multi-family development opportunities that are planned for sale once rezoning and densification entitlements are achieved.