Sean Breslin
Analyst · Citi
Okay. Thanks, Tim. Turning to Slide 5. This chart represents the trailing 4-quarter average rent change for our same-store portfolio and shows the East and West converging to average roughly 3%. During Q3, however, rent change for our East Coast portfolio was 3.6%, 80 basis points greater than the 2.8% produced by our West Coast assets. The last time our East Coast portfolio outperformed the West from a rent change perspective was Q4 of 2010.
During Q3, the East Coast portfolio was led by a 4.6% rent change in New England, up 50 basis points year-over-year; and 3.8% in the mid-Atlantic, up a very healthy 140 basis points year-over-year. On the West Coast, our Pacific Northwest portfolio produced like-term rent change of 4.1%, which was essentially unchanged year-over-year. Northern and Southern California delivered rent change in the 2.5% to 3% range, each down more than 100 basis points year-over-year.
Turning to Slide 6. I'd like to highlight a few of the components of revenue growth in the first half and the second half of this year. As indicated on the chart, we expect relatively stable rental rate growth, which is the primary driver of same-store revenue growth throughout the year. However, as I mentioned during our Q2 call, revenue growth in the first half of this year benefited from the burn-off of lease-up concessions from new entrants into the same-store pool, a reduction in bad debt and healthy revenue growth from our retail portfolio. In total, these components contributed an incremental 70 basis points to rental revenue growth during the first half of the year.
We don't have much of a tailwind from those same components in the second half of the year, and the benefit we are realizing is being offset by the impact of rent caps in L.A. and the recently adopted rent regulations in New York. As a result, revenue growth in the second half of the year is more in line with actual rental rate growth.
Turning to Slide 7. I'd like to share a little bit about what we're doing on the innovation front, which will enhance our operating margins and allow us to reach new customers. As indicated on the left side of Slide 7, we're leveraging various technologies, our scale and new organizational capabilities to create value through a number of initiatives, including those identified on the right side of the slide.
Some of our margin-enhancement initiatives relate to leasing and maintenance service, which I'll address in more detail shortly, along with customized renewal offerings and centralized renewal administration. In addition, we're studying opportunities to use AI, digitalization and various other technologies to improve the productivity of our property management organization, including our call center operation.
We're also using our scale and technology to reach new customers. In the residential space, a segmentation study indicated that roughly 10% of the renter market would prefer a furnished apartment home. We started offering furnished apartment homes in select locations about 18 months ago. Based on early results we expect to scale it to 5% or more of our portfolio over the next couple of years.
In addition, we are pursuing a strategy to profitably serve the limited service segment of the rental market through the development of a new community featuring high-quality apartment homes and amenity-light design and limited community services. As compared to our typical development community, we expect to reduce capital cost per home via thoughtful design, choice of materials and the elimination of almost all the amenity space. On the operating side, we expect to reduce operating expenses by eliminating most of the on-site staff as most of the customer interactions would be facilitated by technology and the cost of maintaining what tends to be expensive amenity spaces. The net benefit to the customer is a rental rate approximately 10% to 20% below other new communities in the area. Our first pilot community is currently under construction, and we expect initial results in the next 12 to 18 months.
Turning now to Slide 8 to provide more detail on a couple of initiatives. About 18 months ago, we mapped out all the customer journeys tied to leasing an apartment and created a new technology-enabled self-service model for most leasing activities. We started implementing the first phase of our redesigned customer journey earlier this year, which includes the use of an AI-powered automated leasing agent and the adoption of a more dynamic demand-driven staffing model. Our automated agent is now fully deployed across the entire portfolio.
The screenshot on the right side of Slide 8 represents a clip of a recent text conversation our agent had with a prospective resident. The automated agent operates 24 hours a day, 365 days a year, and we're seeing improved performance metrics as a result of our adoption of this technology, including about a 700 basis point improvement and leads to our conversion ratios. We implemented our new staffing model in 2 regions this year and expect to adopt it across the entire portfolio by the end of next year. We've seen a substantial improvement in productivity across the 2 pilot regions and expect similar results in our other regions. Other components of the new leasing model included more self-guided tours and self-service move-ins. Overall, we expect to realize about a 50 basis point improvement in our same-store operating margin as a result of our new approach to leasing, which is primarily driven by an increase in the productivity of our leasing teams.
Turning now to Slide 9. We've also created a road map for our new maintenance service model. There are several phases to the plan, but it includes digitalized workflow and procurement, automated scheduling via a new optimization platform, the application of data science to predict demand and enhanced associate performance metrics. We're in the process of integrating the new maintenance platform with our other enterprise systems, which would allow us to implement the first phase in Q1 2020 and realize stabilization of roughly midyear 2021. We expect another roughly 50 basis point improvement in our same-store operating margin from our new maintenance service model, which is primarily driven by an increase in the productivity of our maintenance teams.
And lastly, turning to Slide 10, I'd also like to provide an update on some of our environmental initiatives. Over the past few years, we have invested in a number of opportunities to reduce energy consumption and carbon emissions across our portfolio, including LED lighting, which is already generating more than $3 million in annual utility savings; and on-site solar generation, which we have started to install more broadly after completing several pilots. We are on track to have almost a 6 megawatts of carbon-free, power-generating capacity installed by the end of next year, providing strong returns on a $20 million investment and with more opportunity to extend solar into additional assets in future years.
With that, I'll turn it over to Matt to talk about development and Columbus Circle. Matt?