When someone decides to do without supervision, they are comparing a known figure, the fee, with an invisible one, the risk. The comparison looks favourable until the project reaches a point where nothing can be corrected without demolition. It is worth making that risk visible.
The four sums nobody does at the start
Variations with no technical challenge. On a typical refurbishment contract, variations submitted without verified justification frequently run between 8 % and 20 % of the contract value. Some are legitimate, arising from unforeseen conditions. The rest is simply what was poorly measured in the original tender and is now charged as an extra. With nobody comparing measurements against the drawings, and the payment record against what was actually built, every claim looks legitimate.
Defects that only surface once they are closed up. Patched waterproofing, pipework never pressure tested, concrete poured without cover control. The cost of checking is one site visit; the cost of correcting is opening new finishes and paying twice for the same work.
Delays with a financial effect. Every month of delay on a financed project accumulates interest, alternative accommodation and, on rental assets, income not earned. Delay rarely comes from a dramatic event: it comes from decisions that waited weeks for an answer.
Handover records with no evidential value. Signing off practical completion without a defects list closes the door on the claims that are easiest to win. It is the cheapest mistake to avoid and the most expensive to repair.
What gets checked, and when
Before starting. Verification of the design and engineering packages, coordination between disciplines, a programme with milestones, a budget with measurements checked, the contractor's insurance and licence, site set-up and neighbouring conditions.
Foundations and structure. Levels and setting out, reinforcement geometry, concrete cover, delivery tickets and compression tests, pour and joint sequencing.
Shell and envelope. Masonry and restraint, treatment of thermal bridges, waterproofing inspected before it is covered, terrace drainage, window fixing and sealants.
Services. Pressure tests on water, tightness on drainage, verification of boards and protective devices, coordination of routes before ceilings are closed.
Finishes and handover. Flatness and alignment, junctions exposed to moisture, commissioning tests, and a written defects list with deadlines and an owner for each item.
Supervision does not exist to distrust the contractor. It exists so the client makes decisions with the same information as the contractor, at the same time, rather than three weeks later.
What changes in practice
On a supervised project, variation requests arrive with checked measurements and a written recommendation. Payments follow what has been built, not what has been invoiced. The client's decisions are recorded and dated. And at the end there is a file: records, tests, photographs by stage, as-built drawings and warranties. That file is worth money the day the property is sold or a warranty is called upon.
Three signs the project needs supervision now
- The contractor submits additional amounts with no measurements attached.
- Work has been carried out that does not appear in the approved design.
- There is no photographic record of the areas already closed up.
If you recognise two of these, the moment to act is now: every additional week increases the cost of putting it right.