Most heritage places have been previously modified to suit changing circumstances and will continue to be modified to ensure that they meet contemporary standards of comfort and amenity. With careful planning and the right advice, the majority of these alterations, additions and extensions can be carried out in a manner that is compatible with the heritage significance of the place.
The Burra Charter (article 3.1) promotes a cautious approach of changing as much as necessary but as little as possible. That is, the extent of change to significant fabric should be minimised as far as practicable.
When planning works, an analysis of the fabric of the place will help to identify opportunities and constraints. Are some parts of the place more important than other parts? Is the integrity of the whole place significant, such as important outbuildings, gardens, landscape features, or has this significance been reduced by past modifications? Is the setting, streetscape, townscape or landscape important?
Other matters which may be relevant include the need to manage significant landform and landscape elements and significant archaeological values.
For places that have been assessed against criterion (c) – potential to yield information - or there are known significant archaeological values, the Heritage Council may require the preparation of a Statement of Historical Archaeological Potential to ensure impacts to significant archaeological values are considered.
9.1 Internal partitions
Installing light weight partition walls (eg: office cubicles, shop fit outs) that:
- does not involve the removal of original fabric;
- does not alter a significant design or layout of an interior space, including historic patterns of access and movement;
- does not impact on significant fabric (eg: ceiling heights, plaster detail such as cornices, timber panelling, skirting, architraves, historic/original wallpaper); and are fully reversible.
| Installing new internal partitions or walls in significant spaces or in a manner that may damage significant fabric or the character of the interior space
Appropriate outcomes:
Avoid dividing or breaking up spaces of high significance. If a space has some significance but must be divided, use walls or partitions that do not extend to ceiling or partitions that have their upper part made of glass.
Partitioning rooms into smaller spaces should be carefully considered and planned in such a way as to retain significant elements. For example, by keeping chimney breasts and fireplace mantels in one space and not dividing them between separate rooms. Partitions should be designed to be reversible so they can be removed at a later date if required, enabling recovery of the space without causing damage to significant historic fabric.
New walls should be configured to minimise the need for alteration of significant features such as windows, stairs, fireplaces, skirtings and cornices. |
9.2 Alterations to significant structures
Alterations to structures or parts of structures that are of little significance, where the work will not result in either a physical or a visual impact on the more significant elements or spaces of the place. | Alterations to significant structures or alterations in a location where the new work will result in either a physical or visual impact on the significant elements or spaces of a place.
Appropriate outcomes:
In places where the fabric has relative levels of significance, altering fabric with lower levels of significance is preferable to altering fabric with higher levels of significance.
It is desirable that alterations to significant fabric be reversible.
In some cases significant external characteristics of a place should be retained such as:
- the presentation of the place to the street, particularly where a place contributes to the significance or character of a streetscape or townscape;
- the essential form of the place, including its scale, construction materials and their appearance (i.e. unpainted brick or stone should remain unpainted);
- roof form and roof materials, chimneys, door and window arrangements and their joinery details (e.g. glazing divisions in sashes);
- design details of particular interest or value such as verandahs, decorative mouldings, carvings, joinery or ironwork.
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9.3 Works to non-significant structures (ie: modern buildings, sheds, garages)
Minor alterations, additions or extensions to structures or parts of structures that are not significant, where the work will not result in either a physical or a visual impact on the significant elements or spaces of the place. | Additions or alteration to a non-significant structure where the new work will result in either a physical or visual impact on the significant elements and spaces of a place.
Appropriate outcomes:
Alterations, additions or extensions to non-significant structures should be designed to be in sympathy with the significant elements of the place, and to result in the least possible intrusion into significant views or spaces.
Impact on areas of archaeological potential should be minimised, which in some cases may be achieved by construction methods that do not involve ground disturbance.
New work to non-significant structures should not be imitative of historic elements. However, new work may utilise similar scale, massing, form, material and level of detail as the historic elements in order to be sympathetic to the character of the place. |
9.4 Internal alterations (generally)
New openings into walls that are of little or no significance.
Upgrading bathroom, kitchen or laundry fit-outs where there will be no alterations to significant door and/or window openings and no impacts to significant joinery, walls, ceilings or floors, or significant archaeological values below floor level. | Alterations that involve disturbance or removal of significant fabric such as walls, floors, ceilings, fireplaces, stairs, joinery, or decorative plasterwork.
Appropriate outcomes:
In places where the fabric has relative levels of significance, altering fabric with lower levels of significance is preferable to altering fabric with higher levels of significance.
Retaining significant internal aspects of the place is preferable. This may include:
- the overall room layout and circulation patterns;
- significant elements such as historic staircases, fireplace mantels, cornices, skirtings, floorboards, dado rails, doors, door and window architraves, ceiling roses etc.;
- rare and important decorative finishes such as painted surfaces to imitate stone or wood or rare and unusual wallpapers.
Where alterations involve the removal of early fabric that forms spatial divisions, the work should be planned to retain significant details such as stairs, fireplaces, ornamental ceilings, doors and windows; and the vestiges should be kept of the fabric that is removed. |
9.5 Additions or Extensions
Minor additions or extensions to structures or parts of structures that are of little significance, where the work will not result in either a physical or a visual impact on the more significant elements or spaces of the place. | Additions or extensions to structures or parts of structures that are significant, or to other structures where the work will result in a physical or a visual impact on the significant elements or spaces of the place.
Appropriate outcomes:
Additions or extensions should be subservient to the main historic building. That is, an addition should not visually dominate the historic structure.
Significant public views of a place should be retained when additions or extensions are planned and implemented. Where such works will be publicly visible, care should be taken in the configuration and choice of materials to minimise visual impacts. This may be particularly relevant when considering the height of additions; roof forms, materials and colours; wall materials, textures and colours; and window proportions and arrangement.
Design of new additions or extensions should be sympathetic to the significance of the place.
Where minor or small scale additions or extensions are proposed, a higher level of conformity with the heritage place is desirable. The new fabric can be distinguished from historic fabric by subtle means. For example, by distinguishing minor differences in construction, stylistic details, colour, material, and the junction between old and new. New fabric can also be distinguished by incorporating date or marking devices and by keeping records to document the feature as new works.
Where the additions or extensions are substantial, it is appropriate that the new work is more easily distinguished from the historic part. This can be achieved through a variety of approaches from traditional (ie: design that is in-keeping with the original, but subtly different) to highly contemporary (ie: design that is a contrast with the original). Poor quality imitation or mimicry of historic building forms and styles should be avoided. Designs that provide a visual contrast between old and new should be visually compatible and sympathetic to the historic elements, and should not diminish the place's significance.
Take care to avoid ongoing conservation problems at the interface between the historic place and the addition or extension. For example, construction details in new works should avoid breaching damp proof courses or preventing the ventilation of historic fabric which may lead to damp issues that are difficult and costly to resolve post-construction. Position additions or extensions so that significant trees, gardens or garden features are retained.
See section '8 New Buildings' when major additions are proposed, and 13 Historic plantings and landscapes' for further appropriate outcomes. |
Case Study (Extension): Wellspring Anglican Church, Sandy Bay
In 2010, a major extension was constructed at the Wellspring Anglican Church in Sandy Bay to provide a new auditorium.
A number of heritage buildings and values exist at the place, including the significant Henry Hunter Church, the Church hall designed by eminent architect Alan Walker, and a significant c.1925 house next door.
A highly contemporary design was chosen for the auditorium. Set back from the road, the new building is subservient in height to the Church, whilst being unmistakably new with the extensive use of glass and steel. The removal of previous intrusive additions to make way for the new building also allowed the architectural form of the church and hall to be more clearly expressed.
Case Study (Extension): Colonial Georgian house, Sandy Bay
Originally built in 1835, this colonial Georgian house is surrounded by a fine mature garden with dramatic views over the Derwent River.
In 2011, works were carried out to extend the original house with the construction of a new living area located alongside and towards the rear of the building. The architect chose a highly contemporary design for the addition, with extensive use of glass and steel, lightly connecting with the old house via a glazed section.
The materials and details of the old house are referenced in the extension. The classically inspired verandah of the old house, with its paired posts and parapeted roof line, were design cues for the slender steel columns and flat roof of the extension. The new glass front wall expresses the space and shadows of the verandah while also reflecting the sky and garden. The addition is further harmonised with its context by the use of sandstone similar in colour to that used for the house and outbuildings.
The project was recognised for its success, winning the best heritage project and best extension at the Tasmanian Architecture awards and a place on the shortlist in the national awards.
