#LEED-registered school gives lesson in passive and active design

Charles Dickens Elementary is a new 24-classroom K-7 school with gymnasium, library, special education rooms, commons/lunch room, kitchen, and underground parking facilities. It is located in a single-family residential neighbourhood about a 15-minute bike ride from downtown Vancouver.

By Don Nicolson

An entry plaza, flanked by the gymnasium and community garden, addresses the site’s urban edge. It provides a safe outdoor space that is used for play during school hours, as a waiting area for parents at the end of the school day, for after school care, and as a gathering place for the community on evenings and weekends. The gymnasium, multi-purpose room, and commons area are available for after-hours community use.

The building was conceived to minimize its ecological footprint, support opportunities for environmental education, provide a healthy, high quality classroom environment, and reduce energy use significantly. Primary strategies include: a high efficiency geothermal system with heat recovery; underground parking to maximize green space; rainwater harvesting for toilets and landscape use; storm water infiltration swales; rooftop teaching garden; east-west-orientation for best solar utilization; and low VOC finishes.

Sustainable design elements are an important part of the architectural expression. Where possible, they perform multiple functions. For example, the columned shading structure on the south facade of the classroom block not only prevents heat gain, it also provides a covered area for bike parking, while creating a covered link from the entry plaza to the adjacent Sunnyside Park. The teaching garden is also a visible component of the exterior expression.

Internally, the classrooms are clustered around flexible team teaching areas and incorporate operable partition walls, daylighting, and a high level of occupant control of the geothermal mechanical system. Building systems are made visible to maximize their learning potential. The principles of geothermal heat and heat recovery are presented with the help of a viewing panel into the mechanical room. A weather station connected to the school’s network, allows teachers to integrate real-time climate data into their curriculum.

The site is landscaped with native and adapted vegetation designed to supplement educational programs. The roof garden, essentially an outdoor classroom, allows the teachers to incorporate the principles of ecology directly in to their curriculum. Irrigation to this area is supplied by captured rainwater from an underground cistern. The exterior landscape incorporates a swale and pathway that can be used to demonstrate the principles of runoff and the hydrologic cycle. A butterfly garden on the west side of the site demonstrates the relationship of fauna to its ecosystem.

The rainwater collection system saves 1 million litres of potable water per year, with no potable water needed for toilet flushing or irrigation.  Water from the classroom block is collected on the roof, screened twice, and stored in an underground cistern located adjacent to the underground parking.

The building is designed to minimize energy use and maximize daylighting. Oriented on an east-west axis, significant overhangs, combined with shading louvres reduce glare and overheating. Classrooms are designed from first principles to a 2% daylight factor [rather than using the rule of thumb distance from window method] and have perimeter switches located adjacent to the windows helping to ensure that the students understand the relationship between electric light and daylight.

The mechanical system provides a very high level of occupant control, with 36 vertical geothermal wells connected to individual heat pumps adjacent to each classroom. A high efficiency building envelope, and heat recovery at the rooftop exhaust adds to the efficiency of the system.

The institutional nature of an elementary school allowed the team to make design decisions that were based on the expectation of a long service life. The geothermal and water collection systems were the result of this life cycle approach. Brick and concrete are the primary finishes used at grade, ensuring a long lasting building. Flexible classroom designs, which include a large sliding door between all classrooms, allow for team-teaching and integrated classroom layouts, while providing acoustic separation when necessary.

Most importantly the project is seen as a prototype for the Vancouver School Board to explore green design strategies in their new facilities. This is demonstrated in a building tour program [run by the students], a facilities department which monitors the building performance through a network DDC control system, public open houses, as well as community gardens and public space on site which promote sustainable goals through passive means.

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