Maximum sizes for Roof Windows and sashes vary by width, height, wind zone and glazing requirement. Your local Bradnam's branch will be able to advise whether a configuration is possible.
As a guide fixed window panels up to 1000mm by 1500mm width are attainable, however constraints within the NZ Building Code or NZS4218:2009 may restrict the maximum size.
Special flashings are required for installation dependant upon the roof cladding and construction. Ask your local Bradnam's branch for details.
Opening roof windows are normally operated using winding gear which can be manually or electronically operated and can include such options as rain sensors so roof windows can close automatically when rain is detected. Please refer to hardware section.