What is first fix and second fix in construction?
First fix is all the structural and hidden work that happens before the walls are plastered. Second fix is all the visible finishing work that happens after plastering. Together they describe the two main construction phases of any building project, and understanding them helps you read a quote properly and track progress on site.
The plasterer comes in between first and second fix. Getting the sequence right is critical to scheduling, which is why a well-structured quote will separate the two phases clearly.
What first fix includes
First fix covers everything that will be hidden behind plaster and finishes once the job is complete. It is the most labour-intensive stage and typically accounts for 40 to 50 percent of the total build cost on a new-build or extension.
- Stud walls, floor joists, and roof timbers
- Window and door frames (or linings)
- Pipe runs for plumbing and heating
- Electrical cable runs with back boxes for sockets and switches
- Insulation installation
What second fix includes
Second fix is where the house starts to look like a home. It requires precision and a good eye for detail because everything is visible. A poorly fitted skirting board or a socket that is not level will be noticed every day.
- Fitting sockets, light switches, and light fittings
- Connecting taps, toilets, basins, radiators, and the boiler
- Hanging doors, fitting skirting boards, architrave, and built-in storage
- Final decoration and finishing touches
What this means for a quote
When reviewing a building quote, check that both stages are clearly listed and priced. Some builders lump everything together, which makes it hard to track costs or compare quotes like-for-like. A well-structured quote will show first fix carpentry, first fix electrics, and first fix plumbing as separate line items, then the same for second fix. If you use TailoredQuote, you can generate a scope of works with this level of breakdown built in.
Need to turn this into a clear written quote? Start free — no card needed.