Planning Services

Window Alterations

Policy Guidelines for Listed Buildings and Buildings in Conservation Areas

Windows are an important feature in the facade of any building and this is particularly true in Georgian and Victorian properties where historically sash and case wooden vertically sliding windows were installed. Where such original windows are replaced with inappropriate modern substitutes the result can have a detrimental effect on bars the character and appearance of the building. While this is true of the detached property it is even more so where the property is either semi-detached or forms part of a terrace or block of flats.

Before you decide to remove the original windows and introduce alternatives, please consider the following points:

  • Is it absolutely necessary or desirable?
  • Is the property a Listed Building or within a Conservation Area?
  • Do you have the necessary Planning and Building Control Permissions?
  • Can the original sash and case windows be repaired and restored?
  • Will secondary double glazing serve your needs?
  • Have you looked into the cost of replacing timber sash and case windows with purpose made windows to match the originals?
  • A window may look alright in a brochure on its own, but it could spoil the whole appearance of your property.
  • Do not allow yourself to be pressurized into replacement windows until you have fully investigated every aspect including alternatives, any necessary permissions and costs.

Category 'A' and 'B' Listed Buildings

Traditional timber sliding sash and case windows should be used in all elevations. Change in design or materials will not be permitted in all but exceptional circumstances.

Category 'C'(s) Listed Buildings

Sliding sash and case windows manufactured in aluminium and having a plasticised finish with a white woodgrain effect or a UPVC finish of appropriate profile may be considered acceptable. Alternatively the Policy Guidelines for Category 'A* and 'B' Listed Buildings could be applied.

Unlisted Buildings Within Conservation Areas

Replacement windows should match the original in appearance when closed and on the front elevations of buildings should open in the traditional sash manner or using the approved modem tilting sash method. Stepped pivot windows will only be permitted on rear elevations. Alternatively the Policy Guidelines for Categories 'A', 'B' or 'C' Listed Buildings could be applied.

Traditional Timber Sash and Case Windows

Georgian Window
Victorian Window
Georgian Window with glazing bars
Victorian Window may have central glazing bars


Recommended Modern Designs

Stepped Window Pivot
Stepped Window Pivot
Stepped Window Pivot. Stepped to rear elevations only.
These windows should not have external hinges.
   
Tilting Sash Window
Tilting Sash Window
Tilting Sash Window

Variations in Design

A different type of window may be acceptable in an individual new building providing the windows are of a uniform design.

Glazing Bars (Astrigals)

The Council will not insist on replacement windows having glazing bars unless the property is a Listed Building.

  • Glazing bars vary according to the period.
  • The correct number of panes should be used to match the original windows or to reflect the period as appropriate.
  • When windows are replaced, care should be taken to match exactly the original profile.
  • When modern windows are used, glazing bars should not be sandwiched between the two panes of double glazing.

Mullions

Mullions, like astrigals, are an integral part of window design and of the building as a whole. Removal of mullions, while replacing existing windows, requires Planning Permission, and could have a detrimental effect on the character and appearance of the property.

Repairs

Timber windows can usually be repaired and this can be a practical and cheaper alternative to replacing windows.

Double Glazing

Additional glazing units fitted to the outside of existing window are not acceptable.

Forms of double glazing which alter the appearance or operation of existing windows are not acceptable. Modern replacements should have white finish in all cases.

Planning Legislation

  • To alter a Listed Building you require Listed Building Consent.
  • To alter a Listed Building in a Conservation Area you require Listed Building Consent and Planning Permission.
  • Even if your building is Not Listed, if it is in a Conservation Area you require Planning Permission to alter it.
  • Alterations to Flats and Commercial Properties require permission in all areas.

Building Control

Building Warrant permission is not required when you are replacing windows provided the windows being installed comply with the current Building Standards (Scotland) Regulations 1990.

These Regulations contain a variety of design requirements for window including:

Ventilation

The opening of the window(s) must not be less than 1/30th. of the floor area of the room unless the room has adequate mechanical ventilation.

The height of the opening part of the new windows must be no less than 1.75 m.above floor level.

Where possible the windows shall incorporate an adequate trickle ventilator.

Safe Cleaning

Any part of a window more than 4m above the adjacent ground must be constructed so that it's external and internal glazed surfaces can be safely cleaned from inside the building.

Daylight

The area of glass in the window(s) must not be less than 1/15th. of the floor area of the apartment.

Emergency Access Window

A suitably designed and located emergency access window must be provided:

a. in a dwelling, in every storey at a height of more than 4.5m but not more than 11m where the storey has only one escape route; and

b. in certain types of buildings in every bedroom in an upper storey at a height of not more than 11m where the storey has only one escape route.

Emergency Escape Window

A suitably designed and located emergency escape window must be provided in every apartment:

a. in an upper storey at a height of more then 4.5m except:

an apartment in a flat which is served by more than one escape stair; or

b. which is an inner room.

General Safety

Windows at ground level must be so designed that they are not a danger to any person passing the building when the window is open.

Grants

Grants administered by the Building Standards Department under Housing Acts may be available. For advise please contact the Building Standards Department of the Council at Burns House.

Conservation Areas

Ayr 1 Central* Ayr 2 Alloway Ballantrae 1 Ballantrae 2
Barr Burns Monument* Colmonell Crosshill Dundonald
Dunure* Girvan Kirkmichael Kirkoswald Maybole*
Monkton St. Quivox Straiton* Symington

* Denotes designated Outstanding Conservation Areas