First fix
First fix (sometimes described as shell and first fix ) is a short-hand term used to describe the processes that are undertaken during construction works up to the point of applying internal surfaces – typically plaster. It is normally used in relation to the work of specific trades such as carpenters, plumbers and electricians.
Generally first fix will include constructing the structure, cladding, flooring, doorframes, stairs and so on and installing cables for electrical and ICT distribution, pipework for water and gas distribution and heating ventilating and air-conditioning (HVAC) distribution. First fix is not normally visible when looking at the finished building. Where possible first fix should be tested before second fix (for example, plumbing riser stacks).
Second fix takes place after the internal surfaces have been applied. It comprises those items that are visible in a finished area and are held back to avoid damage, or sadly sometimes theft. This may include fitting internal doors, skirting, architraves, handrails, fixtures and fittings, including connection of appliances (such as electrical equipment, sanitaryware, radiators, and so on) testing and commissioning. For more information see: Second fix.
Typically there will be a change of trades operating on the site, and a break in activity for some trades between first and second fix.
In hotels and residential work there is sometimes a third fix of fixtures and fittings of high value that require fitting or service connections such as chandeliers, white goods, picture-lit artwork and fabrics.
As first fix, second fix and third fix do not have accurate standard definitions, it is very important that contract documentation sets out precisely what work is to be carried out and by who, rather than relying on ambiguous short-hand terms.
NB BG 87/2024, Useful Information Guide, written by Chin Hang “Kay” Lam and published by BSRIA in 2024, defines first fix as: ‘Work done in a new building up to the point that plaster is applied to walls, typically including (but not limited to) pipework, cable runs and back boxes. This term is typically used in housebuilding but may also be used in other types of project. While there is no universal definition, it generally relates to work done by plumbers, electricians and other trades on their first visit to a house.’
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Generally first fix is not visible when looking at the finished article. Where possible first fix should be tested prior to second fix such as plumbing riser stacks. Second fix comprises those items that are visible in a finished area and are held back to avoid damage, perhaps paintwork or sadly sometimes theft. In hotels and residential work there is sometimes a third fix of fixtures and fittings of high value that require fitting or service connections such as chandeliers, white goods, picture lit artwork and fabrics.