Where materials money is well spent

Money goes first into what ends up hidden and is expensive to redo: the full electrical installation with a new board and separated circuits, quality plumbing, membrane waterproofing in showers and wet zones, thermal-break external joinery, and insulation fitted while the walls are already open — doing that later costs three times as much. Save safely on replaceable finishes: mid-range taps, plain internal doors, standard paint, decorative lighting, and mid-range sanitaryware, where the step up to top range is aesthetic rather than functional. The mistake that costs most is picking a premium material from the catalogue and then trimming the installation: first-grade porcelain badly laid sounds hollow, cracks its joints and lifts. Labour is part of the material.

Into what ends up hidden and is expensive to redo: installations, waterproofing, insulation and external joinery. A mediocre finish is replaced in a day; a mediocre installation means opening walls again.

High priority — do not cut here

• Complete electrical installation with a new board and separated circuits
• Plumbing: quality pipe and valves, not the cheapest white label
• Shower and wet-zone waterproofing with membrane, not just paint
• External joinery with thermal break and good glazing
• Thermal and acoustic insulation while walls are already open — doing it later costs three times as much

Where you can save safely

Replaceable finishes: mid-range taps, plain internal doors, standard paint, decorative lighting. All of it can be upgraded later without opening anything.