This project is located beside the five lamps in Dublin. Six storeys in height, its plan is wedge shaped with its two higher floors stepped to blend its form into the Georgian landscape on the adjacent streets. Its scale, rhythm and use of materials is designed to reflect adjacent historical structures.
This architectural façade fenestration is varied:
- Stick curtain walling and punch hole windows are installed into precast brick panels on the first, second and third floor. These have been standardised to suit the precast techcrete panel opening sizes.
- Ribbon curtain walling is installed on the fifth and sixth floor. Set out to an agreed module, the tolerance is taken up at its ends to reflect the change in shape of the building profile.
- Brise soleil horizontal shading is provided on fifth and sixth floor, each corner site measured and in some instances templates taken.
- The drum at the corner is six storeys in height, faceted in plan and at its head; this Structural Sealant Solution (SSG) required bespoke structural concealed clamps to toggle fix the face glass to the stick system.
The sixth floor of this project was an addition to the undertaken works impacting on the drum, penthouse glazing, stairwell area and brisesoleil. Architectural façade engineering playing a role in bring these elements together.
Using Value engineering techniques, an architecturally detailed internal structure was built to provide horizontal wind restraint to the storey and half glazing at sixth floor drum area.
Added value to the glazing workpackage achieved through careful and optimum use of space benefitted all parties concerned. The additional height of the envelope defines the envelope solution as a landmark façade solution in its locality.
Face Glass Aesthetics
The Structural Sealant Glazing (SSG) to the drum is fritted, black in colour the slim-line 20mm vertical/horizontal banding to face two of the external pane is an important part of visual appearance of this project. Fritting on face two protects the edge seal of the insulated unit against degradation adding to the whole life performance of this critical element of the façade. Fritting adds value to the whole life performance of the façade by extending the service life of the insulated units.
The solar control glass to the drum is hard coated enabling the ceramic printing of each perimeter edge on face two. Face four is concealed by using a dedicated flipper type gasket.
The solar control glass is neutral in colour and although its performance properties are very different to that of clear float glass, there is little visual difference when viewing externally.
Façade Risk Management
The drums glazing configuration comprises of 6mm toughened external /20mm warm edge spacer bar and 8.4 laminate internally. The use of laminate was deemed by the systems company as critical to the glass remaining in situ in the event of breakage.
A thermal fracture analysis was carried out to ensure differences in surface temperature on the glasses surface would not cause the laminate to fracture. Shading as a result of nearby buildings, street furniture, building overhangs, brise-soleil, internal blinds etc. are important factors to consider in analysing the risk of thermal fracture on each facade orientation. Such features are bespoke to each and every project in its environment and climate. The glazing configuration must be carefully considered as part of its whole life Facade Risk Management strategy
The glass spandrel panels between intermediate floors are ceramic painted on face four. Ral 7037 matt in colour, they form an important architectural backdrop to the external metal ral 7016 matt colour.
Glass Spandrels are normally toughened to resist thermal fracture, however with toughening, the risk of spontaneous fracture increases do to the presences of Nickel Sulphide Inclusions (NSI). Engaging Façade Risk Management techniques, the risk was managed by Heat Strengthening the inner pane which meant that in the event of fracture the inner pane would remain in-situ.
The architectural façade glazing work package incorporated the following works:
- Structural Sealant glazing (SSG) to six storey drum
- Roof-glazing over stairwell area on fifth floor.
- Pocket glazing on ground floor.
- Architectural cladding and channels on the third floor and around the base of the drum.
- Ribbon curtain walling glazing to penthouse areas.
- Punch–hole windows and curtain walling to precast brick panels.
This project uses a Mix-mode ventilation approach, the building is air conditioned complimented by top hung opening sashes integrated into curtain walling. Strategically situated, the façade fenestration promotes the use of cross natural ventilation.
Day-light / Shading Strategy
The Face glass is clear in colour allowing maximum light transmission internally into the deep open plan offices. The horizontal brise soleil provides shading to office area at fifth and sixth floor. The extension brise-soleil regulated by a solar shading analysis for optimum effect.
Projects of this nature set in the urban environment are challenging, rapid construction in a tight site with poor access requires expert project management through-out procurement design and construction.
Engaging ADT FA+CE techniques adds value to the architectural glazing and cladding work-package. Our understanding of façade glazing risks throughout procurement provides or clients with a unique confidence in our continued ability to build facades collaboratively.