Loft conversion with Dormer from £15,000 to £30,000

Estimated time taken (6 to 8 weeks)

Largely depends on size of dormer, timescale would be discussed prior to work commencing.

For this project, building regulations are required, planning permission is not always required,

depending on size and position of extension.

What’s involved?

Installation of steel work to front and rear of loft space to provide support for new floor and dormer.

Installation of floor joists.

Fit velux windows (if required)

Erect walls to form dormer extension and roof

Build stud walls to form rooms as needed

Insulate all walls and roof to current building regulations

Plasterboard all walls and ceilings and skim to a smooth finish

External Works

Tile dormer walls to match existing

Fit UPVC soffits, fascia’s, and gutter’s to dormer

Supply and fit two UPVC windows to dormer


Staircase installed with hand rail and spindles to match existing

Doors, skirting boards, architraves to match existing

(Fire doors fitted where needed due to building regs)


Carried out by a Part P Approved electrician

Sockets, light switches, smoke detectors as needed


Carried out by a Gas Safe Approved plumber

Radiators, en-suite bathroom as needed

PLEASE NOTE – The above work can also be carried out on a hipped roof, which would involve changing the hip to a gable.

Project details

  • Estimated time taken

    6 – 8 weeks

  • Cost

    from £15,000 – £30,000