Eldridge Oaks - Taking Advantage of Site Constraints
By: Carleton Riser, managing director, development & investment, Transwestern
Over one third of Eldridge Oaks’ 21-acre site is open, allowing for an adjacent 10-mile hike and bike path.
Transwestern wanted to take advantage of tightening office market conditions in Houston’s Energy Corridor and began searching for a development site in late 2006. In order to execute the development plan, the company needed a site that was suitable for a Class A office project that would be attractive to large, corporate users prevalent in the area.
Maximizing the Competitive Edge
Houston’s Energy Corridor had become a premier suburban submarket dominated by energy companies operating in all facets of the industry. Much of the growth in the area was triggered by the establishment of global exploration and production centers for Shell, BP and ConocoPhilips, with the latter companies ultimately turning these locations into their North American and corporate headquarters respectively. In addition, the collaborative nature of this business had driven energy service companies (i.e., engineering, equipment leasing, etc.) and smaller "independent" energy companies to locate there as well. The submarket is characterized by large tenants operating in an increasingly competitive environment for the scarce technical talent required to operate their businesses. With growing consistency, these tenants view a superior office environment not just as a requirement, but as a potentially differentiating quality in retaining and recruiting employees.
Transwestern contracted for a 21- acre site that met all the conventional real estate criteria such as access and visibility, but also had the unique attributes of being wooded as well as adjoining a large, public greenspace. However, the site had development challenges related to the intertwined issues of a floodplain, natural drainage features and stormwater management. The site is adjacent to Buffalo Bayou, which is effectively a river that serves as the primary conduit for stormwater drainage for much of the prairie land west of Houston, and the city itself, into Galveston Bay. A portion of the site is within the floodplain of the bayou and the site also included natural drainage pathways that could not be disturbed by development. Finally, stormwater management regulations mandated that the development of the site include on-site detention to mitigate the impact of runoff into the municipal system due to the addition of impervious cover.
The development team engaged engineering firms Walter P. Moore and SWCA to assess the implications on site planning, density and cost. Work was conducted concurrently with architects from Kirksey to devise methods to turn the site’s challenges into advantages. The design goals for the project could be summarized as follows:
- A two-phased project that could be operated as single-tenant or multi-tenant buildings or as a single-tenant campus;
- A practical limit on density with the first phase being 300,000 to 400,000 square feet;
- A highly efficient floorplan suitable for both closed and open plan layouts;
- LEED® Silver designation certification;
- A parking ratio of four spaces per thousand square feet in a multi-level structure;
- High quality exterior and interior finishes that could be delivered within the cost constraints of a suburban market.
Reworking the Site Plan
The two-story lobby features include FSC-certified walnut and fumed oak panels accented by marble and granite flooring.
The engineering analysis revealed that material portions of the site were undevelopable without significant cost and entitlement risk. It also put limitations on the flexibility of the site plan by establishing boundaries for the location of structures. After numerous iterations, the development team settled on a site plan that concentrated the buildings and parking on the site in a manner that achieved its planning goals while leaving over a third of the site as greenspace. The phasing plan would allow the buildings to be built so they could function cohesively and for the phase one garage to be expanded horizontally. This combination allowed the footprint for structures and access roads to be kept to a minimum. The area of the site to remain undeveloped was situated along the public park which has the practical effect of expanding the already generous greenspace contained within the property boundaries.
It was decided to construct the initial phase of the project on the park side of the site as opposed to the alternative, which is the hard corner of a lighted intersection. The long side of the rectilinear building runs parallel to the parkland and the two-story lobby is situated so that arriving tenants and visitors are greeted by a wooded area framed through the glass curtainwall. The landscape plan includes a minimalist approach to allow for the private land to blend seamlessly into the public realm. Park benches are situated in the wooded area on site and simple trails provide access to a 10-mile hike and bike path that runs adjacent to the site. Finally, shower and locker room facilities are provided as an amenity for tenants wishing to take advantage of the park.
Blending Nature with Function
The heat island effect at Eldridge Oaks is minimized through the use of high reflectance concrete for all paved surfaces.
Phase I was completed in September 2009. The building is a 14-story concrete structure with a total of 350,000 square feet of leasable space. The project includes a multi-level precast parking structure. The majority of the façade is comprised of precast concrete panels and ribbon windows. The front of the building has a glass curtainwall feature element running vertically for the length of the façade and the south elevation has a metal band that serves to break the building into different elements. The double height lobby is designed to focus attention toward a glass wall that frames the exterior greenspace, which includes landscaping adjacent to the building and the pre-existing, more forested condition beyond. The interior finishes include granite and marble flooring and wall materials consisting of FSC-certified walnut and fumed oak wood panels accented with aluminum panels and reveals. The elevator cabs have glass and aluminum panels and carpeted floors.
The first building is expected to receive LEED® Silver certification in 2010. The entire project team worked diligently and creatively to maximize the sustainable elements of the project which include:
- minimizing the heat island effect through the use of high reflectance concrete for all paved surfaces and reflective roofing materials;
- reducing the building footprint, thus preserving much of the native forest;
- utilizing native plant species that provide a habitat for local animals and encourage biodiversity;
- leaving open space equal to more than eight times the built area;
- minimizing site lighting, directing all light down to the ground;
- using recycled content to make up more than 20 percent of materials used on the project;
- consuming local materials (concrete, fill and landscaping materials) that were both harvested and manufactured within 500 miles of the site;
- using sustainably forested wood for the lobby wall panels and high-efficiency mechanical equipment and building controls.
It should be noted that relatively few LEED® points will be generated by the site planning decisions because of how credits are assigned. However, these decisions were based on the broader merits. The development and leasing team believes the project accomplishes the planning goal of being a sustainable development beyond the technical aspects of LEED accreditation. These are attributes that the occupants of the building will be able to see and experience in a very tangible manner.
The characteristics of the site provided planning constraints that have been turned into attributes that differentiate Eldridge Oaks from its competition. These features may not be paramount to every prospective tenant, but could be attractive as companies analyze the subjective features of an office location that more completely serves their overall space objectives.