This article from AB Heritage looks at what you need to consider when planning to use uPVC window replacements in historic buildings.
The UK has the oldest housing stock in Europe according to an Historic England article dealing with energy efficacy and sustainability of historic homes. The article notes that an estimated 20% of homes in England (roughly 5 million buildings) were built before 1919. And while only a small proportion of these are Listed Buildings, many more fall within Conservation Areas (nearly 2 million) and may therefore require additional planning.
For Listed properties authentic windows and doors are a key element of the architectural and historic special interest of the building and contribute to the character of any property. Windows provide a connection between the interior of a building and the world outside, that goes beyond the purely physical or functional. The style and size of windows holds much information regarding the age and economic status of a building, as well as providing insight into past uses.
Historic England (2017) views the proliferation of ‘unsympathetic replacement of windows and doors – usually PVC-U’ as one of the key detriments to the special architectural and heritage interest of historic areas (including Conservation Areas). This means that a proposal to replace original (or historic) windows with uPVC units is likely to come under scrutiny from Local Planning Authorities and Conservation Officers, especially where the existing windows are of the traditional single glazed and timber-framed variety.
For those wishing to change windows in Listed properties or homes within conservation areas, failure to obtain the correct permissions can potentially lead to enforcement action to rectify non-permitted work and / or even lead to prosecution under the Listed Buildings and Conservation Areas Act of 1991. Doing early research and, seeking advice from a professional Heritage Consultant is a good use of time to avoid issues later and potentially, to save costs.
Proposed works that may affect the special architectural and historic interest of a Listed Building will require Listed Buildings Consent (LBC). Where a building is not Listed but is located within a Conservation Area, Planning Permission for upgrading and renovation works may still be needed. These works are covered by Article 4 Directions.
Essentially, Article 4 Directions are used to remove ‘permitted development’ rights to control small incremental changes to properties that have the capacity to erode the ‘character and appearance’ of a Conservation Area. Your local authority can confirm if your property is subject to an Article 4 Direction.
Repair or Replace?
Proposals to repair and retain historic windows will always be viewed more favourably than proposals for outright replacement. By retaining the historic fabric of windows, and by maintaining the historic glazing, you can be assured that your works will be authentic and will properly reflect the special architectural and heritage interest of the building. Proposals that seek to reinstate historic fenestration will also enhance the special architectural and heritage interest of a building. In short, proposals that seek to retain windows or to reinstate historic windows, will be considered by planning to enhance the special architectural interest of a historic building.
Historic England’s 2017 publication ‘Traditional Windows – Their Care, Repair and Upgrading’ advises that “an existing window … should only be replaced after it has been agreed with the Conservation Officer that it is truly beyond practical economic repair” and Historic England provides guidance on how to replace historic windows, ensuring they replicate the existing window components, including jambs, cills and glazing bars.
When the windows and doors are determined to be beyond repair it is crucial that you source a replacement that is an accurate replica of the original in terms of design, craftsmanship and materials. Factors to take into consideration include:
- Replication of size, shape and the proportion of the window as well as the unit profiles including the glazing bars.
- Authenticity of glazing and glazing fixing methods; and
- The painted finish.
A Heritage Consultant such as AB Heritage will be able to provide you with guidance and establish what ‘original’ fixtures, fittings, and joinery are appropriate on your historic building. Your consultant will liaise with the Local Planning Authority on your behalf and provide the necessary technical documentation to take your Listed Building Consent / Planning Application forward.
AB Heritage is a professional Heritage Consultancy operating across the UK. The company is registered with the Chartered Institute for Archaeologists, the body that sets and oversees high standards for commercial archaeology in the UK. www.abheritage.co.uk
Author: Elli Winterburn, Senior Heritage Consultant, AB Heritage.