Before work can start on site your architectural designer will need to produce a set of drawings that comply with the building regulations. S/he will gather this information from key trades/suppliers and other advisors such as the structural engineer, but will mostly draw the plans up from their own detailing, based on the non-technical planning drawings that were submitted to the authorities to get planning permission.
Construction drawings include all detailing for structural components as well as every layer of certified product that is to be installed, including manufacturer specifications for things like windows and doors, insulation, airtightness and thermal bridging details as well as how ventilation units and ducts are to be installed.Specialist suppliers may provide their own set of drawings for each of these details; this is especially common in the case of ventilation. Electrical points will also be included with specialist drawings for these, usually drawn up by the architectural designer to give to the electrician.
n NI, the building control officer will need a complete set of plans prior to starting in order to ensure the design is compliant with current building regulations. In ROI, this document is required to file your commencement notice on the Building Control Management System.
Construction drawings are also the starting point to getting prices from the trades and for structural engineers to work out the loads for items such as the steel beams. Indeed, all specialist items will be taken into consideration by the structural engineer, e.g. chandelier will require structural support in ceiling structure,heavy baths or jacuzzis may need additional support on upper floors, and RSJs or steel beams will be required for open spans.
A procedure must be in place to ensure only the latest version of the construction drawings is ever available on site.