What this work involves
An extra storey changes more than the roof. The existing structure, staircase position, escape arrangements and installation routes need to be considered together. Establish what the building can support before settling the design.
- Existing structure and foundation assessment
- Stair opening and usable room layout
- Roof shape and neighbouring buildings
- Facade materials, windows and insulation
- Lifting, scaffolding and temporary weather protection
Use the following design considerations when coordinating this service with a wider project. Agree which parts apply to your request.
Compare an addition with the existing window arrangement and entrance.
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 the drawing needs to explain
Place existing and proposed elevations side by side and add a window-opening section. Mark visible changes and elements requiring adaptation inside.
Decide this before construction
Assess the existing detail before selecting products. Then coordinate insulation, ventilation and visible finishes so one improvement does not create an unexamined consequence elsewhere.
Cost factors for this service
Include design, investigations, structural work, the new envelope and internal finishes. Additional strengthening can change the budget.
Bring this to the discussion
Existing plans, photographs of roof and facades, intended rooms and information about earlier alterations.
Questions about the work
Is every flat roof suitable for another floor?
No. The building, its foundation and the rules for the property are decisive. Structural assessment and a location-specific permit check belong in the preparation.
The design situations here illustrate choices; they are not completed projects or a diagnosis of your property.

