A440.1-98

1. Scope 1.1 Classifications and Test Requirements Classification levels and test requirements provided within CSA Standard A440 and this Special Publication allow a purchaser or specifier to select windows suitable to their specific climatic conditions, height of installation, type of building, etc. The authority having jurisdiction assigns the minimum levels to be met. All other classifications and test requirements exceeding those specified by the authority having jurisdiction are considered optional. 1.2 Climatic Selection Design data is included in the Supplement to the National Building Code of Canada (NBCC), listing 640 selected locations in Canada. A specifier should reference the NBCC Supplement to ensure that historic climatic data support the selection and to provide the user, regardless of location, with the same minimum level of performance. NBCC Supplement data are reprinted in part as Table UG-1 of this Special Publication. 1.3 Occupancy Classification The NBCC specifies two distinct building categories. The first category, small buildings, is covered in Part 9 of the NBCC. Small buildings are defined as buildings of three storeys or less in building height that have a building area not exceeding 600 m², and that are used for residential occupancies, business and personal service occupancies, and medium- and low-hazard industrial occupancies. All other buildings are covered in Part 4 of the NBCC and are defined as all buildings used for assembly occupancies, institutional occupancies, and high-hazard industrial occupancies, as well as all buildings exceeding 600 m² in building area or exceeding three storeys in building height that are used for residential occupancies, business and personal service occupancies, mercantile occupancies, and medium- and low-hazard industrial occupancies. Within this Special Publication buildings falling in this category are referred to as "Other Buildings". 1.4 Building Height and Shape All wind speeds are reported at a height of 10 m. Buildings of heights greater than 10 m will be subject to greater wind speeds. The shape of a building creates pressure coefficients that may increase or decrease pressures on the building. 1.5 Terrain Wind speeds are normally reported at flat open locations. Wind velocity in any area varies with terrain conditions from centres of large cities to country, from rough hilly terrain to open flat grassland and coastal areas. Table UG-1 in this Special Publication is a simplified, quick guide for isolating the appropriate performance range for water leakage, wind load resistance, and condensation resistance. The levels suggested are minimum levels for basic buildings. As windows are considered cladding, the user is encouraged to refer to Part 4 of the NBCC, which covers design of building cladding. Part 4 also requires that wind test pressures be increased by coefficients that reflect the influence of building height, building shape, and gusting. This Special Publication also assists specifiers and manufacturers by offering commentary and background related to CSA Standard A440. It requires the user to make several choices from among optional requirements in order to select the appropriate product and level of performance to reflect the needs of the building. Performance levels recommended in the charts do not guarantee against product failure. Calculations are based on minimum requirements and include a designed potential or recurrence of failure. A short-form checklist of the decisions a specifier must make in order to utilize this Special Publication properly is included following Clause 14.