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

Compare the complete intervention
Include internal making good and possible sill adjustments with facade work. Compare options using the complete work package around the opening.
Which trade-off matters?
New performance and existing proportions need assessment together. A different frame profile can affect glass area, reveals and internal finishes; compare the complete detail, not just the product rating.
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