Dormer WIndow Design Guide

The design of dormer windows to roof slopes for most dwellings (bungalows, semi-detached, detached, terraced, single and two storey) require careful design consideration. Most home owners principal requirement is for additional floor area but often at the cost of an ugly and overly large dormer window or two that sits incongruously within the roofs setting.

A balance must be achieved between gaining the additional floor space and the external appearance or impact of the dormer window external form and bulk. If the balance is not achieved, a poorly designed dormer can detract from a properties value. DO NOT sacrifice a good externally pleasing design for simply obtaining maximum floor space.

A properties roof line is probably one of the most important design features - its crowning glory so to speak. If you start installing obtrusive roof projections that are out of scale and poorly placed, the most dominant part of a properties feature can appear totally trashed not to mention its possible neighbourly elements. Some dormer windows require specific and formal Planning Approval where most Planning Departments of Local Councils will protect and preserve the local character so there is already some form of design control. At the other end of the scale is the Permitted Development route where some dormer windows can be built without any design checks or balances from the Planning Department. This aspect alone has probably caused more incongruous roof extension design than no other.

Dormer window design guide - traditional dormers

Dormer window design guide - technical

Dormer window design guide - general

Dormer window design - general