A clear budget starts with clear scope.
The cost follows from the existing building and the agreed work.

Compare the complete intervention
Include shading, controls and the finishes around glazing from the start. A proposal omitting them is difficult to compare with one that already addresses comfort fully.
Which trade-off matters?
More glazing does not automatically make a better room. Compare continuous glass with a combination of glazed and solid wall areas so views, furniture and shelter each have a place.
What belongs in the budget?
- Survey, investigations and design preparation.
- Demolition, foundations, structure and new building elements.
- Electrical, water, heating and ventilation work.
- Windows, floors, walls, kitchens and bathrooms.
- Access, protection, scaffolding and waste removal.
- Clearly identified provisional sums and change arrangements.
A starting price needs a defined scope.
Ask for work, materials, VAT, assumptions and provisional sums to be clearly described. Undecided items should remain visible so an early estimate is not mistaken for a fully developed final budget.
Compare the content
Consider preparation, protection, timing and reinstatement alongside the total price.
Read the quote comparison guide