On a trip to Sacramento in 2012, esteemed British architecture critic and essayist Peter Buchanan visited the Bateson Building, with which he was familiar but had never seen. By happenstance, he also visited the Lincoln Plaza Building, which he immediately identified as a little-known masterpiece. Both buildings are seminal works in our midst.
Under Buchanans guidance UK-based The Architectural Review has embarked on a program of Revisits, in which projects that have promised much are re-evaluated a number of years later. Under that program, I was approached to write a Revisit of these two buildings. The following is a slightly amended version of that article.
Lincoln Plaza demonstrates that a building can form a comfortable backdrop to the tree-lined corridors and sidewalks of Sacramento. It is totally user-centric and much loved by the people who work there. It is elegant and timeless.
Bateson illustrates the optimism, foresight, and commitment that a young design team led by Sim van der Ryn brought to architecture during the oil-crisis of the mid-70s. It is a travesty that the ideas embedded in the building were abandoned with such indecent haste. It is hoped that the systems of natural pre-heating and pre-cooling will be reinstated in accordance with the recommendations of a study commissioned by the State of California a few years ago.
A Responsive Architecture
With its can do attitude, the USA responded to the oil crisis of the 1970s, and California led the way in imposing speed limits on the highways and fuel efficiency standards on vehicles. In 1978, California passed a set of energy-efficiency standards for buildings, which challenged Architects to design in a more energy-efficient manner. In the early 70s, architects experimented with low-energy buildings, generally at the residential scale. Sim van der Ryn was a pioneer in this green design movement, and when he was appointed California State Architect by newly elected Governor Jerry Brown in 1975, an opportunity to take these ideas to a larger scale presented itself. Both van der Ryn and Brown were admirers of Gregory Batesons Steps to an Ecology of Mind and E.F. Schumachers Small is Beautiful, published in the early 70s.
The first large-scale building that showcased what we now call sustainable architecture was a State Office Building in Sacramento completed in 1978, named after Gregory Bateson and designed by a team led by van der Ryn and Peter Calthorpe. It introduced ideas that were radical for its time, and it has been vaguely known in sustainable design circles that its various energy saving systems were not used for long, but little is known as to why. A few years later, a less published office building, the Lincoln Plaza Building for CalPERS (The California Public Employees Retirement System) designed by Len Blackford of local architectural firm Dreyfuss & Blackford, was built nearby and completed in 1986. Both buildings are ideal subjects to revisit as California continues to lead advances in sustainable building.
Climate and Urban Approach
To review the two design approaches and systems employed, one first needs to understand the climate and urban geography of Sacramento. Summers are hot and dry with gentle, cooling southwest night breezes and an average temperature in July of 93º F. Winter brings 17 inches rain and cool temperatures, with a January average of 44º F. The city, with shady, tree-lined streets and flat topography, is laid out as a grid, and a relatively high water table makes on-site parking uneconomical below one subterranean level. Van der Ryn envisaged a network of parking spaces surrounding the city under the overhead freeways, with buses taking State employees to their offices. Trips between State offices could be on foot or bicycle. Consequently, the Bateson Building has no on-site parking. Lincoln Plaza occupies two co-joined city blocks and has a sunken level of parking reached by ramps, with pedestrian bridges providing access at street level. Both buildings are rectangles that effectively fill the city blocks. In so doing, they share a similar parti, which is arrived at from two contrasting positions.
Similar Partis, Different Points of Departure
It is no coincidence that the building van der Ryn and Calthorpe designed was named in honour of Gregory Bateson. Bateson championed what he called the pattern that connects man and the natural world, and van der Ryns overriding design intent was a climate responsive building that would illustrate the interrelatedness of individuals, societies, and ecosystems that Bateson spoke of.
On the other hand, CalPERS emphasised more the human dimension for Lincoln Plaza. As managers of the state employees vast retirement fund, CalPERS relies on attracting the best and brightest workforce. The brief presented to Len Blackford was to create the best working environment possible. The client conducted a detailed cost-benefit analysis focused on employee productivity; a 5% to 15% increase in productivity could be achieved through improved interior environmental factors and the psychological qualities of the individual workspaces. With that approach in mind, Blackford focused on creating optimal spaces in every respect, working with department heads from the inside-out.
Faced with similar spatial programs250,000 sf. on one city block for Bateson, and 500,000 sf. on two city blocks for Lincoln Plazaboth designs opted to fill the site and create edges that are shielded on all four sides by abundant street trees.
In the Bateson Building, conventional construction elements perform multiple tasks in an interactive manner. The building has an exposed concrete lattice-frame structure, providing thermal mass to capture, store, and release heat internally in winter months. In summer, the structure is purged of heat by the cooler night air, allowing it to absorb heat internally during the day. Within this exposed concrete structure, aluminum framed window systems and exposed wood spandrel panels fill the grid. In some areas, the structural grid is exposed both vertically and horizontally as pergolas and outdoor terraces, breaking up the edges. To express the interrelatedness of systems, van der Ryn has expressed the essence of the concrete and wood in an unadorned, brutalist manner. It is unusual to see exposed wood used so extensively; with street trees four stories tall, the building blends into the streetscape.
The edges are also handled differently to address their solar orientation. On the east and west façades, motorized bright yellow canvas shades drop vertically from the horizontal concrete beams to keep early morning and late afternoon sun off the glass. The south façade has a horizontal concrete extension of the lattice structure with closely spaced concrete beams to cut the southern summer sun, while the north façade is unshaded.
Similarly, Lincoln Plaza fills the site, while the parking level for 500 cars acts almost like a sunken moat around the building, with pedestrian bridges to the entry points on three sides. The west elevation has direct street access to loading docks. The concrete floors of the building typically cantilever five meters; the cantilever has pre-cast concrete panels fixed to the edge of the slab holding an 18 deep planting bed with planting that cascades over the edges and effectively camouflages the building. Visually, the building disappears into the foliage and street trees. The concrete is well finished, and the continuity of the panels provides a horizontality that was commonplace in early 80s office buildings. All four façades are handled consistently, and the depth of cantilever provides a deep recess for sun control. It does inhibit, to some extent, light penetration on the north façade. The cantilevers are also accessible for window and planting maintenance. Exposed concrete columns are round and gently interrupt a continuous glazing system. Deciduous street trees provide additional shade in summer and allow winter light to penetrate effectively.
The building has a cool elegance, and the stepped floor plates and extensive planted roof decks elicit comparisons with the work of Arthur Erickson in Vancouver. Erickson called concrete the marble of our time, and the juxtaposition of concrete and lush planting was regularly seen in Ericksons early work. Sacramento has a vastly different climate from Vancouver, and Blackfords Lincoln Plaza is a startling oasis of visual coolness and respite from the hot and dry Sacramento summers.
Energy efficient Approach: Bateson Building
Organizationally, both buildings have perimeter office space arranged around a central atrium. In the case of the Bateson Building, this is a crucial component in van der Ryns view of a climate responsive building, with the four-story unconditioned space acting as the lungs of the building. It is in the design of the atrium that the energy-efficient ideas are manifested and the integration of systems is played out.
The atrium roof has a saw tooth profile with clear glazing on the north-facing incline and operable vertical louvers facing south. On the roof, solar panels assist in heating the domestic hot water. General office lighting comprises fluorescent light fixtures placed between acoustical baffles under the concrete soffits, supplemented with individual task lighting.
Although the building is linked to the States Central Utility Plant, which provides steam and chilled water to more than twenty State-owned buildings in downtown Sacramento, the intent was to design a building that would use 80% less energy than a conventionally designed building. This would be done by pre-conditioning the air by passing the air from the atrium over two 600-ton subterranean rock beds located beneath the atrium floor, heating it in winter and cooling it in summer. At night, air from the atrium would be passed over the rock beds and supplemented and moistened with evaporative spray air washers. In winter, the released thermal mass of the exposed concrete structure together with heat from the Central Utility Plant passing through the rock beds would have the effect of pre-heating the air. In the atrium, vertical canvas tube ducts and fans were employed to prevent stratification by pushing the warm air downwards.
In 1976 in Philadelphia, a mold infestation in an air-conditioning system led to the outbreak of pneumonia at an American Legion Convention and soon acquired the name Legionnaires Disease. The Bateson Building opened in 1978. In 1981, a class-action suit was lodged on behalf of state employees who worked in the building. Although no disease could be attributed to the pre-heating and pre-cooling rock bed design, the State deactivated the system soon thereafter, and the building now operates fully off the Central Plant piped steam and chilled water system. The abrupt deactivation of the Rock-Bed Thermal System without the collection of monitoring data enabled critics to rather unfairly dismiss the buildings energy reduction ideas in totality.
Occupant discomfort could be largely attributed to faulty variable air volume control boxes that reduced the air supply to occupants. In addition, a rushed completion schedule and late installation of fabrics and carpeting containing the irritant formaldehyde caused additional discomfort.
In 2008, the State of California commissioned an infrastructure study, which examined the building in considerable detail. The findings were that the roof-mounted solar water heating system was removed mainly because of roof load. The report determined that the possibility of mold, together with control considerations, was the prime reason for the deactivation of the rock-bed as a means to pre-heat and pre-cool the air in winter and summer. In addition, the atrium socks were disconnected, as the atrium is not heated and there is minimal stratification.
The study concluded that the Bateson Building can be repaired, retrofitted, and brought into compliance with current codes together with LEED Silver or Gold certification for existing buildings at 20% of replacement cost. In addition, the recommendation includes the re-installation of the Rock-Bed Thermal Storage System with some modifications. For example, the use of water to cool and add moisture to the air would be eliminated, thereby removing mold concerns. Critically, however, the original design in 1978 was based on a fresh air ventilation requirement of 5 cubic feet per minute per occupant. Current code requirements are for 15 cubic feet per minute per occupant. The atrium cannot be used as a source of fresh air, and this increased requirement will increase the heating and cooling loads to be met.
Energy Efficient Approach: Lincoln Plaza
Since the Lincoln Plaza is double the floor area of the Bateson Building and covers two city blocks, the plan is arranged around two interior spaces. The first is an enclosed atrium with glazed roof, and the second is an open courtyard adjacent to the cafeteria and auditorium; it can also be used as a spill-over space. Overlooking the open courtyard, an extensive outdoor roof garden with significant planting further blurs the relationship between the building and the street trees.
While the Bateson atrium plays a critical part in the passive heating and cooling of the workspaces, Lincoln Plaza adopted a different approach to the significant challenges of cooling the building in the summer months. Since the project was located in what was then a predominantly residential area, an early decision was made to minimize external noise from cooling towers and boilers. Consequently, a ground source heat pump system was installed. The building condenser water system consisted of a single-pass, ground water cooling and heating system from two wells, the water then re-injected into the aquifer. With groundwater at a consistent 64º F, the building could be pre-cooled prior to summer mornings by only using the well water. As the temperature rose, the heat pumps would kick in. In winter, the heat from the computer room equipment was captured and used in augmenting the heating cycle.
The groundwater contained iron bacteria and the filter screens needed cleaning and flushing with chemicals. Since this was an open loop system, the compliance cost for chemical discharge became more onerous and costly, and together with rising general maintenance, a decision was made after twenty-two years of successful operation to disband the system and replace it with conventional roof mounted chillers and boilers. Replacing the open-loop system with a closed-loop system requiring multiple wells would have been a more costly solution.
The thermal mass of the building is significantly increased through extensive landscaping, which covers approximately 145,000 sf. with an annual maintenance cost of approximately $1.30 per sf. This allows for significant periods of time during normal operations when a combination of outside air from the heat exchangers and recirculation of inside air can maintain desired temperatures without input from chillers or boilers.
The buildings HVAC, pumps, lighting, etc. are controlled by a sophisticated Digital Energy Management System (EMS). Thermostats are set by the EMS, and occupancy sensors cycle lighting off if there is no movement in a particular space. After-hour workers can dial up incremental lighting in their area, while general after-hour lighting is sufficient for access and egress only.
Interior Workspaces: Bateson
An occupant survey revealed general satisfaction with the work areas in the Bateson Building. Thermal control, however, appeared inadequate to more than 50% of respondents, and general workspace lighting levels were considered poor by approximately 30% of respondents. The survey revealed that a large majority viewed the atrium as a positive feature and that it enjoyed individual and departmental use. In summer, it was particularly well used, but in winter a majority found it to be too cold, with inadequate lighting levels, particularly on cloudy days.
By implementing the Infrastructure Reports recommendations, the occupant concerns regarding thermal comfort can be addressed. Some ill-considered interior space planning changes have compromised the light penetration from the atrium into the surrounding office spaces. Coupled with reduced exterior light once the motorized blinds are lowered on the east or west façades, natural light is reduced and the building is more reliant on expensive artificial lighting.
Fabric blinds that achieve the right balance between light penetration and heat transfer can be sourced, and general lighting levels can be improved quite simply by painting the concrete soffits which have dulled with age and reduced the intensity of reflected general lighting levels.
Interior Workspaces: Lincoln Plaza
By contrast, Lincoln Plaza benefitted from the attention paid to employee comfort and flexibility requirements. All office spaces have raised access floors to enhance flexibility and are used for power, data, and telephone distribution. Indirect lighting, task lighting, glare-free general lighting, acoustic workstation panels, flexibility in workstation configuration, and visual connection to outside light and greenery all contribute to a workspace environment that has consistently received praise from employees.
Hard-walled spaces are located in the internal core of the building, and open office spaces are visually linked to the exterior greenery. Meeting rooms are confined to the inboard edge of the open office spaces and arranged at right angles to the window wall to maximize external light penetration. Interior office spaces have been well managed, and the architects continue to be engaged in designing all changing spatial requirements. Generous outdoor green spaces on each level provide employees the opportunity to conduct small group meetings formally or informally or to just enjoy the peaceful surroundings.
This might be a more common approach today, but thirty years ago in the era of utilitarian office space, it was quite far-sighted. It has borne fruit in the fact that employees are reluctant to leave the building and relocate to the newer CalPERS building completed a few years ago. There is no doubt that the quality of light, the generosity of outdoor green space, and the mature way in which employee needs were addressed, plays a significant part in this view. Over a period of time, all buildings undergo interior reorganization of workspaces. Here it is evident that Lincoln Plaza has controlled and managed this aspect very successfully by retaining Dreyfuss and Blackford to manage and design the changes faithful to the original organizing principles. On the other hand, the Bateson Building is subject to different contracting protocols, and continuity in design input is harder to achieve.
Maintenance and Comfort
The limited exterior material palette on both buildings does make ongoing maintenance rather efficient. On the Bateson Building, the only areas where exterior deterioration has occurred are in the sealants between concrete, wood, and aluminium and in the waterproofing of outdoor terraces. Modern-day sealants and waterproofing materials are vastly superior to the products available in the 70s. Notwithstanding these advances, the original materials have stood up well over the thirty-five years since installation. Despite extensive raised plazas and landscaping on Lincoln Plaza, there have been relatively few waterproofing issues. In fact, the landscaping has largely protected the waterproofing from the degradation associated with heat and sunlight. With almost no direct sunlight on the window systems, all sealants have held up well.
Both buildings are well mannered in the way they merge into the Sacramento streetscape. The Bateson Building uses wood panels to make a material connection between the façades and the adjacent trees. Lincoln Plaza uses extensive rooftop and edge planting to achieve the blurring of building and street trees and becomes a willing backdrop to nature.
Yet the points of departure for the two buildings are starkly different. The Bateson Building sought to make construction elements multi-functional, which was a buzz-word in the 70s. For example, the concrete beams act as structure, heat-storer, pergola, and a device to hang canvas sunscreens. Energy-flows are evident in the Bateson Building, with the canvas tubes in the atrium drawing immediate attention to an element that has sculptural qualities and at the same time provokes an immediate question as to their function. It does come to mind that the health and comfort of the occupants might have played a secondary role in the resolution of the energy-saving methods attempted.
On the other hand, Len Blackford explained that the design approach on Lincoln Plaza centered on the individual and on the creation of a comfortable workspace. For example, the structural grid was driven by making the spaces relatively column-free for flexibility, but also to ensure that no workspace was far removed from a source of natural light and a visual connection to greenery. The organization of the plan also provides broad corridors that lead to outdoor rooftop green spaces. Whether it is a visual connection with the outdoor street trees, or access to the abundantly planted roof decks, the natural world is always easily accessible to employees.
Revisits linked to the proving or otherwise of initial design hypotheses are most rewarding. Unfortunately, the State of California never tested the Batesons hypothesis of an 80% reduction of energy consumption, which would lead to the building paying for itself in twenty to thirty years. Similarly, the employee-centric design approach on Lincoln Plaza, which was expected lead to a 5% to 15% increase in productivity, has not been measured.
Despite this, the Bateson Building is better understood, and recommendations to re-activate the Rock-Bed Thermal Storage System are welcomed. What is also evident is that this revisit reveals the Lincoln Plaza Building to be a relatively little-known 1980s masterpiece deserving of wider recognition.