Dormer Extension Plans

Plans for Dormer Extensions and Windows

Dormer extensions significantly increase the floor area and useable living space in your loft.

The survey establishes the roof dimensions: height, width and length; the general condition and suitability of loft and house for extension; the sources of utilities and the external house characteristics such as location of neighbouring properties.

New Minimum Height Rules

Lofts now need only reach the minimum height at the access and entry point to convert into a habitable room built to Building Regulations Approval. Height should be 1.8 m minimum at the edge of a stair with 1.9 m at the centre line if the ceiling is sloping.

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See page 7 of Approved Document Part K for diagram and explanation. The new regulations allow lofts with low ceilings to conform to standards - so you can significantly add to the value of you house and the uses you loft space can be put to - such as a child's bedroom.

A loft survey provides us with the information on which to give professional advice and guidance as to feasibility and scale of a project, and how existing property features and controls may affect loft plans and layout.

Dormer construction

We develop design plans that indicate the detailed dormer design, e.g. position of stairs, windows, internal walls, power sources, and plumbing.

Architectural building plans are drawn from agreed design drawings and submitted in a planning permission application for planning and building regulations approval.

Planning Permission

Planning permission applications are used to ensure dormers are built (from a council's viewpoint) in the right place (protecting amenity and environment in the public interest), to the correct size, layout, sitting and external appearance of your house.

Because dormers have a visual impact specific regulations govern their external appearance.

Many Councils require 'they are not out of character with the ... area'.

Dormers need to be in-character with the neighborhood and your property, so extensions and windows are designed to a style that generally blends with the existing look and feel of your home.

Design plans specify the pitch of roof, building materials and style of window decoration.

Street facing windows generally have a higher visual impact, as they are more visible. Planning approval may be more difficult to obtain for dormers that extend both back and forwards from the roof.

The visual appearance of neighbourhoods is an important feature in property prices and preserving the original appearance of an area will be a part of the planning officer's consideration.

This is particularly true within conservation areas where permission is required even to insert skylights within a roof.

Dormer windows that will to face over neighbouring properties may also run into objection as there is a potential intrusion on privacy.

Architectural Plans

Dormers are covered by many planning controls and regulations. Our experienced architectural and building plans service and advisory role can save you a significant amount of time and cost at this early stage.

Our specialist architectural surveyors will design your dormer using their professional construction experience to the agreed designs.

When Above-It-All bring their expertise, understand and experience into a project from the outset it allows us to guide you through the correct decision making process and arrive with the most suitable loft plans for your property.

When we understand your requirements, usage plans and the design ideas we can then introduce you to the most appropriate designs and materials, e.g. electric under floor heating or space saving insulation or fitted cupboards.

Rear facing dormer

Many roof dormers require a compromise between maximisation of living space and having plans approved. Often dormers are designed for the rear of a house and have a VELUX® skylight installed street facing side so that they pass.

Local planning departments provide their own guidelines on loft and roof development, some general guidelines usually apply:

• The dormer loft extension should not be higher then the original roof line.
• The outwards extension of the dormer towards the street frontage should generally be set back at least a metre from the front wall of the property.
• The sideways extension of the dormer to the side wall or party boundary should be set back half a metre to prevent the design being overbearing.
• The rear facing dormers should be set back half a metre from gable wall or party boundary to prevent overshadowing or loss of privacy to neighbouring properties.
• Dormers generally cannot extend around the corner of a hipped roof.
• Maximum roof area to street frontage is usually about one third.
• To prevent overlooking of neighbouring properties, side elevations are usually considered undesirable.
• Dormer windows require an unobstructed opening area at least: 0.33 metres squared, 450mm high and wide. Bottom of opening area needs to be 1100mm max. to 800mm min above floor level and 1700mm max. above the eaves. The window may be wall end of the roof.

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