A lower total is not automatically better value. Compare the work, materials and finishing included in each proposal first.
Compare the complete intervention
Compare the glazing, rooflight and terrace reinstatement together in the budget. If a cheaper door system requires a different floor build-up, include that consequence in the same comparison.
Align the scope
Use the same headings for preparation, demolition, structure, installations and finishes. Mark missing items and distinguish fixed prices from provisional allowances.
What the drawing needs to explain
Draw one section through the kitchen, glazing and terrace. Include finished floor levels, the roof edge and shading position; separate supplier sketches do not fully show these relationships.
Which trade-off matters?
A wide garden opening takes away wall space for cupboards. Compare a fully glazed rear wall with a smaller opening and a targeted rooflight, looking at both from the same seat.
Questions for your own property
- Is the finish level equivalent?
- What is excluded?
- How are changes recorded?
Illustrative design situations, not evidence of completed work. Assess decisions against the actual property.