1. Get the structural design right first

A £600 structural engineer review at design stage can shave £4–8k off steel costs by sizing the beam properly. Most overpriced quotes assume worst-case steel.

2. Buy the kitchen, doors and tiles yourself

Builders mark up materials 15–25%. Buy bi-folds, kitchens, bathroom suites and tiles directly — pay the builder a clear fitting cost. Saves £3–10k on a typical extension.

3. Avoid winter starts

Concrete pours, screeds and renders all suffer below 5°C and need protection or delay. A January start often becomes a March build, with you paying winter rates.

4. Fix the spec before quoting

Vague spec = padded quote. The more clearly your scope is defined (door make, tile size, socket count, paint colour) the tighter the price comes back.

5. Compare against Newark-on-Trent benchmarks before signing

BuildPriceIQ shows you what a Newark-on-Trent builder typically charges for the same scope. Three of four quotes usually cluster within 6–8% of that figure — the outlier is the one to negotiate or drop.