What are prelims?
Prelims (short for preliminaries) in construction are the costs associated with running the project, outside of labour and materials. Prelims are a miscellaneous assortment of items, and it is useful to know which ones could affect your project, because you will ultimately be paying for them.
Some builders explicitly reference prelims as part of their quote, whilst others absorb them within the overall price. Either way, the prelims to be aware of for your extension will be one of two types.
If the building company is a larger outfit, they may allocate a project manager to oversee the build, and this management fee might be designated as a prelim. The same is also possible if the builder used a quantity surveyor to price the job during the quotation stage.
The 2015 CDM (Construction [Design and Management]) regulations set out the health and safety responsibilities for domestic projects, but the full suite of requirements probably won’t apply to your project on account of there being fewer than 20 workers on-site. However, the builder may carry over some health and safety elements and list them as preliminary items, such as the production of a risk assessment and various building method statements.
If the builder offers an insurance-backed structural warranty as part of the offering, the insurance premium for this may also be passed to you as a prelim, and some builders may opt to recoup time spent sourcing materials as a procurement cost.
2. Site-related prelims
Chief amongst site-related prelims are the costs associated with setting up the building site so it’s ready to work in. Site set-up costs include perimeter hoarding and scaffolding, and security disbursements like a temporary alarm system or keypad site entry.
If a temporary kitchen or bathroom needs to be established because the main ones are out of commission during the build, then these might also be classed as prelims. As would the cost of waste disposal – predominantly skips; or wait-and-load waste clearance if you live in a more built-up area, where the cost of a parking bay suspension to accommodate a skip is prohibitively dear.
Welfare facilities and health and safety equipment/clothing are also classified as site-related prelims, as is plant hire (mini diggers, kango drills, safety platforms and other such equipment). Another would be ‘setting out’, which involves staking the ground, sometimes by a professional surveyor, to transfer the parameters from the plan into the building site so that walls are built in the right place. Water and electricity may also be attributed as prelims, as could site decommissioning and end-of-job cleaning.
Now you know a little more about prelims in construction and how they apply to your extension. They may or may not be made explicit in the quotation or contract, but many of them will make an appearance during the quotation and physical build stage.