Loft Conversion DesignArchitectural plans, drawings and planning services for loft conversions.

Building/loft floor plans for loft conversions, dormers, trussed roofs and attic roof extensions.

Planning permission for loft conversions in Manchester is not normally required. However, permission is required where you extend or alter the roof space and it exceeds specified limits and conditions.

Under new regulations that came into effect from 1 October 2008 a loft conversion for your house is considered to be permitted development, not requiring an application for planning permission, subject to the following limits and conditions:

  • A volume allowance of 40 cubic metres additional roof space for terraced houses
  • A volume allowance of 50 cubic metres additional roof space for detached and semi-detached houses.
  • No extension beyond the plane of the existing roof slope of the principal elevation that fronts the highway.
  • No extension to be higher than the highest part of the roof
  • Materials to be similar in appearance to the existing house
  • No verandas, balconies or raised platforms
  • Side-facing windows to be obscure-glazed; any opening to be 1.7m above the floor.
  • Roof extensions not to be permitted development in designated areas
  • Roof extensions, apart from hip to gable ones, to be set back, as far as practicable, at least 20cm from the eaves.


Types of Loft Conversion


Velux and rooflight are the same conversions. This type of loft conversion is generally very cost effective and does not need planning permission.


A Dormer loft conversion is an extension to the existing roof, allowing for additional floor space and headroom in the loft conversion. Internally a dormer will have a horizontal ceiling and vertical walls compared to the normal diagonal sides of a loft conversion. In attics that have limited space or head height a dormer loft conversion will provide additional space that can make a conversion easier.

Hip to Gable

A hip to gable loft conversion requires major changes to the roof. A gable wall is built up to the ridge point and a new section of the roof is built to fill in the gap.


A mansard roof has two slopes, the lower slope is close to vertical at 72 degrees and the top section of the roof is almost horizontal. A mansard loft conversion makes a lot more available space within your loft.


SITE ID: Loft Conversion | Planning Permission | Manchester