Having previously written about the conceptual design and building layout of the new nursery school at Sillogue, we now conclude with the development of the design in cross section, and the environmental considerations.

As seen in our previous post, the main classroom accommodation spans north to south, enabling the classrooms to benefit from a westerly aspect. This has proven to be quite beneficial in controlling heat loss, as it enables the building to have almost no windows on the colder northern edge, and limited windows to the overshadowed east elevation. In addition, the openings on the south facade of the classroom block are limited to a series of small individual ‘spyholes’ arranged in a star constellation (the pattern of which will be clearly visible outside the building when the internal lights are lit on dark winter’s evenings), so there are no concerns of excessive solar gain to this facade.

The main west facade has therefore required most attention in our attempt to balance the competing demands of limiting heat loss, reducing solar gain and ensuring adequate daylight and ventilation. The placing and sizing of windows has therefore been critical, and the eventual configuration of 4 generous windows arranged in a grid ensures that the higher level windows allow daylight to penetrate deep into the room, with the lower windows maintaining views into the courtyard and beyond. In addition, each room features a further lower ‘spyhole’ window, by means of a door or small fixed window at floor level, at a height suitable for small children.

The glazing used has a reasonably high G-value of 0.34, to prevent excessive solar gain. Thermal dynamic modelling of the building has proven that natural ventilation is adequate for almost all of the building, with cooling only provide as a back-up to the catering specification kitchen and infant sleeping areas, if required.

Although the external walls are generally constructed in blockwork and brickwork, the west facade is constructed in 225mm deep timber joists to allow greater flexibility in window positioning. The voids between are full filled with quilt insulation, and in combination with the 50mm cold bridging insulation internally, it achieves a U-value of 0.13W/m2K.

The timber structure is the perfect substrate for the Tegral cladding boards. These have been configured in various widths in a series of stacked horizontal bands, each separated by a sloping Tegral sill detail. Mixed with the largely white coloured panels are a series of randomly located, narrow recessed grey coloured slots to accommodate the ventilation outlets and smaller ‘spyhole’ windows. In addition, highlights of colour are used at window locations. This rich, colourful and animated main elevation, inspired by the grid-based paintings of Piet Mondrian, contrasts nicely with the remaining simple and understated elevations in brick and painted render.

The building has now just been completed, and Our Lady’s Nursery are due to move into the building shortly. We would like to take the opportunity to wish Sr. Majella and her staff many years of happiness in their new home.

Here’s our second feature on the thought process behind the design of the new nursery at Sillogue, but first we’ve attached a work in progress image taken in the sunshine yesterday (if you’re questioning why some lines don’t match up, 2 photographs have been joined to make a panorama)

 

 

Building planning and configuration – Level 0

As the northern edge of the building is defensive with limited potential for window openings, all ancillary accommodation (such as the kitchen, plant and storage) are located here, with the classroom units positioned on the southern facade of this block, addressing the courtyard playground. All other ground floor classrooms are sited along the west facade of the main block, with the circulation to the east, an edge of the building that is again defensive. There are also some shared support facilities, such as toilets and art rooms located between classrooms.

However, as you will see on the following image, there is also a roof terrace playground at first floor level, which is connected to the ground level playground by a ramp wrapping around the south, east and north edges of the building. The ramp (and its guarding) provide a set-back along this edge, allowing for the introduction of a number of openings in glass block, which allow light into and views from the circulation corridors behind this east facade, while still maintaining security. In addition, the guarding to this ramp, formed by the flemish bonded brickwork perimeter wall, allows the defensive boundary wall to step down to a more human scale at the southern and western street edges.

The central resource space is located at the main entrance, at the ‘knuckle’ between the two wings of the building. Again as illustrated on the following image, this space is top lit by means of a large roof-light.

 

Building planning and configuration – Level 1

The east/west wing is largely all single storey, which allows for the first floor play terrace. A small store is provided for play equipment to the western boundary. The first floor classroom accommodation is to a similar layout as the level below, although some additional consulting rooms, a library and a staffroom are provided at the northern end of this block. The classrooms at this level benefit from additional clerestorey windows to the east, at the change in profile between the sloping roof of the classroom block and the flat roof of the circulation space. A number of circular rooflights animate and illuminate this corridor.

 

Building planning and configuration – Level 2

A covered area is provided to both playgrounds on their northern edges, to provide shelter in poor weather. The ground level canopy also provides cover along the approach to the main entrance, as it links (and also helps to identify) the entrance gate at the site boundary, with the entrance to the building. The only second floor accommodation is a small accessible roof terrace, above the first floor plant and storage room to the northwest corner. The purpose of the terrace is solely for fun; it is the highest point of the building, and it’s expression is as a contemporary version of a medieval tower, complete with turret, spyholes and flagpole (which will feature a flag designed by the nursery children).

 

To follow: Environmental considerations

For ‘Sillogue Nursery – The Design Process (Part 1)’, click here.

For ‘Sillogue Nursery – The Design Process (Part 2)’, click here