Replacement Windows and Doors

The built environment, where we live and work, is of great importance to our quality of life. This sets out Dundee City Council’s policy and advice for the replacement of windows and doors. Windows and doors contribute greatly towards the character and appearance of individual buildings, and the wider historic environment. Original windows and doors are an essential part of a buildings' history, and a significant element of its architectural design.

Best practice advice regarding windows and doors is to repair and upgrade rather than to replace. The loss of original windows and doors to historic buildings can be catastrophic as the properties integrity can diminish through inappropriate replacements and alterations. Timber sash and case windows were the dominant window type in Scotland from the late 1600's until the mid-1950's. The reason for this is simple: they are extremely practical and durable, well suited to the Scottish climate. 

Although in some circumstances planning permission is not required to alter or replace sash and case windows the council encourages property owners to retain these traditional window types.   

Repair to original sash and case windows, is generally the most appropriate course of action and does not require planning permission.   

In general terms, for the replacement of sash and case windows, the best practice is to retain the existing proportions, true three-dimensional effect, transom height and astragal details.   

When replacing sash and case windows on elevations which are immediately visible to public view, the original window proportions should be replicated. The true three dimensional effect of a sash and case window should be imitated so that the top half is proud of the bottom half to give the appearance of sash and case windows when closed; the transom bar should be at the same height; and the same number and thickness of astragals should be replicated for each window. For other window types, for example casement or top opening windows, then the existing proportions, number of glazing bars and colour should be retained.   

Sometimes additional controlled ventilation is required, and preferred best practice should be followed. If additional ventilation is required this should be achieved by means of discreet/concealed vents, rather than by the addition of prominent trickle vents.  

Repair and upgrading of original sash and case windows is the often the most economic solution in terms of cost and long term viability. Sash and case windows can be taken apart relatively easily and timber sections repaired without having to replace the entire unit, as can pulleys and weights. Any draughts, rattles, wear and tear can be resolved by repairing and upgrading to improve their performance both in terms of heat and sound insulation. Historic windows are often constructed of superior quality timber compared to modern timber available today, therefore if properly maintained a repaired window shall often outlast any replacement.

Energy conservation is necessary in addressing climate change. Increasing energy efficiency (increasing thermal and reducing noise) is a major priority today. Existing historic sash and case windows can be upgraded to modern standards of efficiency without the need for replacement. Various system include draft stripping seals, upgrading existing glazing, use of shutter / heavy lined curtains and the introduction of secondary glazing.

With advancements in glazing technology it may also be possible to install double glazing into the existing historic window, this may require additional work to be carried out as a result of the increased weight of the glazing, including works to the weights and pulleys. The installation of double glazing is not normally the most cost effective way to increase its energy efficiency.

Although it will normally be best to repair rather than replace original windows, there are instances where they have deteriorated beyond economic repair, and also cases where previous replacement windows have failed. Where replacements are necessary, the best practice is generally to specify units as close to the originals as possible. Even where elevations of buildings have been considerably altered by window replacements in the past, it is still the aim of the City Council to achieve consistency of appearance by progressing towards eventual restoration to the original unity and character of the elevation. This would therefore require the original proportions and glazing patterns to be present within the design and installation of the replacements to maintain the visual continuity.

There are 3 different categories to consider: properties which are Listed Buildings, unlisted buildings located within a Conservation Area and those neither a Listed Building nor within a Conservation Area.

The windows of a listed building form an important part of its character. Listed building consent is required for any works affecting that character.

Best practice advice received from Historic Environment Scotland is that repair to original windows and doors is the most appropriate course of action and does not require listed building consent (in most instances).

However the extent and specific details of the works shall be required to be submitted and approved by Dundee City Council's Planning Team prior to the commencement of any works.

Replacement or alterations to windows and doors which affect the buildings character requires Listed Building Consent. Replacement of original windows and doors should only be considered when the quality and function of the windows has deteriorated beyond economic repair. As part of an application for the replacement of windows, detailed justification shall be required to demonstrate that the windows/doors are beyond economic repair. Full details of the existing windows/doors along with specific details of the proposed shall also be required as part of the application.

All works to listed buildings are required to be in accordance with guidance and advice established by Historic Environment Scotland.

Altering the size of the window opening shall require Listed Building Consent.

It is recommended that the Planning Team is always contacted at an early stage to discuss window proposals, so that specific advice and guidance can be obtained on the requirement of listed building consent and the suitability of the proposal.

You do not require planning permission to alter or replace a window that is part of the building’s rear or side elevation, unless the side elevation fronts a road.  (View the Scottish Government's guidance for a definition of fronting a road )  There are no restrictions on materials, colours, proportions or means of opening but we would encourage you to replicate the design and appearance of the existing window, particularly where the window is original or traditional in construction or design.  Please see the advice later on this webpage regarding sash and case windows.

You do not require planning permission to alter or replace a window that is part of the building’s principal elevation (or side elevation that fronts a road) if the window as altered/replaced would be the same or substantially the same as the existing window, as regards the:  

1. manner in which the window is opened and closed,
2. number, orientation and colour of panes comprised in the window, and
3. dimensions and colour of the frame of the window or any astragal bars comprised in the window

(View the Scottish Government's guidance for a definition of principal elevation and fronting a road)  

If the works do not meet these three criteria then then you must, before beginning the development, submit an application to the council for a determination as to whether the prior approval of the authority will be required in respect of the design and external appearance of the proposed alteration to or replacement window.   

This application is known as an application for prior notification and prior approval.  Applications should be submitted electronically via the Scottish Government’s www.eplanning.scot website.   

Altering the size of the window opening may require Planning Permission.   

It is recommended that the Planning Team is always contacted to discuss window proposals, prior to the windows being installed. 

Properties outwith a Conservation Area which are not listed buildings do not require planning permission for replacement windows. 

Altering the size of the window opening may require Planning Permission. 

It is recommended that the Planning Team is contacted to confirm planning permission is not required, prior to the works commencing.

Listed Buildings  

You will require listed building consent to alter or replace a door on a listed building.  Planning permission may also be required.  It is recommended that the Planning Team is contacted to confirm planning permission is not required, prior to the works commencing.

Conservation Areas  

You do not require planning permission to alter or replace a door on a non-listed building within a conservation area where the alterations or replacement are on a like for like basis.

Non-listed properties out with Conservation Areas  

You do not generally require planning permission to alter or replace a door on a non-listed property out with a conservation area.   Works to non-domestic properties may require planning permission if the works would materially affect the external appearance of the property.  It is recommended that the Planning Team is contacted to confirm planning permission is not required, prior to the works commencing.

Where original doors remain, it is better where possible to repair rather than replace. Traditional entrance doors are usually of solid timber construction, either panelled or framed, lined and braced. Often there will be a single or double-leafed storm or outer door, with an inner part-glazed door and screen. This arrangement is suitable for both commercial and domestic properties and provides for daylight and shelter when the outer door is open, and security and insulation when closed. Traditional doors contribute and enhance the character and appearance of Conservation Areas.

External doors should only be replaced when it is not possible to repair an original door. Replacement doors on public elevations shall be required to match the details and design of the existing.

Glazing to an outer door is best restricted to a fixed panel or fanlight above the door, though in a single door arrangement a glazed panel to the upper half of the door may be appropriate. Modern glazed doors will usually be inappropriate to the character of traditional properties and, as with windows, aluminium and plastic frames can lead to long-term maintenance problems.

Building Warrants are not normally required for replacement windows and doors, unless accompanied by structural changes such as the widening of the opening or the creation of new openings.

However, new replacement windows must still comply with the Building Regulations.

Information on compliance is contained within the Scottish Government Domestic and Non- Domestic Technical Handbooks and replacement windows information leaflet which can be accessed by logging on to the Scottish Government Building Standards Division web site.

For historic buildings, where there is a specific need to match existing doors, windows or roof lights, the principle of like for like may still be permitted.

For information where it is deemed that a Building Warrant is required please contact the Building Standards Section of the City Development Department: telephone 01382 433102. email bs@dundeecity.gov.uk