A number of barriers must clearly exist be overcome before the construction sector can become deeply involved in carbon trading markets. These include

the availability of suitable technologies and awareness of them on the part of building and property professionals, owners and occupants. There is also an important need for access to financial expertise, means of coping with uncertainty in the process and level of transaction costs relative to benefits. As one construction professional expressed it, “The key to green office buildings lies not so much in developing the technical side but in adjusting the ecoomic arguments in favour of more sustainable solutions” (McKee 2003).

The following three case studies, taken from US examples in Northern California indicate some of the technologies and design approaches available to implement energy efficiency in practice, and how these might relate to carbon trading.

Case study 1: Hewlett Foundation, Menlo Park

Fig 4: Hewlett Foundation, Menlo Park, California.

Architects (shell): B. H. Bocook; (interiors): HPS Architects

The William and Flora Hewlett Foundation is a philanthropic organization created by one of the founders of Hewlett Packard. Its purpose built accommodation, completed in 2002, is located next to the Stanford campus. The 48000 sq. ft. building is designed to provide office and meeting space for the Foundation.

It also provides facilities for staff, including a gym and refreshment area.

The plan is a shallow U-shape around a central courtyard: due to the shallow plan, most office areas have windows. The interior zones on the upper floor have either rooflights or clerestory lanterns. The side windows are openable.

The building is fully air-conditioned: however, the system uses displacement ventilation supplied from the 18” raised floor, with local controls. On the upper floor, the ceilings are open — increasing potential for natural ventilation and well-controlled lighting.

Large roof overhangs shade the upper floor windows; some lower windows are also shaded by roof overhangs, while others are sheltered by the colonnade which adjoins the courtyard. Lighting controls are sensitive to room utilization, and switch off after 10 mins when not required.

The building has a roof mounted PV system sufficient to power exit signs and emergency lighting in the event of a power cut.

This building provides a field study base for the educational activities of the Jasper Ridge Biological Preserve (JRBP), attached to Stanford University. It is located a few miles from the Stanford campus, about 30 miles south of San Francisco.

The 9 800 sq. ft. building, completed in 2002, is a linear, single story form housing 2 classrooms, a herbarium and administrative offices, a research lab and ancillary spaces including a cold room. Toilets and showers are accessed from outside, and are not within the conditioned envelope of the building. The building’s main axis runs east — west: most eye-level glazing is oriented almost due south. North-facing glazing at high level lights the ancillary spaces; north-facing monitors and rooflights bring daylight to the center of the plan.

The building is naturally ventilated: high ceilings in the main areas provide a plenum and clerestories can be opened manually to give stack ventilation in summer.

Clerestory windows are opened in the evening for night purging: thermal mass is provided by the floor. To minimize heat gain — and heat loss in winter — the building is highly insulated, with walls and roof meeting R-30 standard. High performance glazing is used: double glazed low-e panes with thermally-broken aluminum frames. These are not standard items in California, and were shipped in from out of state.

This building has both PV and solar thermal panels. The PV installation is almost invisible from ground level: the amorphous silicate panels are mounted on the south­facing internal slope of the roof. The solar thermal installation dominates the building’s southern fagade. Six panels sit on the south side of the roof monitors, while the rest are mounted between the eye-level and clerestory glazing of the main spaces. These panels have a secondary function in providing extensive summertime shading to the main south facing windows; the roof overhang gives some shade to clerestories. The primary, glycol-filled loop heats a massive water tank located in an ancillary space: this supplies low-level radiator panels in the lab and offices and ceiling mounted forced convective heaters in the classrooms. A small propane furnace provides a back-up system for cool, dull spells in winter.