Conservation of heritage places | Brisbane City Council

Conservation of heritage places

These guidelines show what conservation and maintenance issues should be considered before undertaking any new work on a heritage place.

Important conservation principles

The following principles for preserving and enhancing the value of a heritage building are in line with the Burra Charter, which provides guidance for conserving and managing places of cultural significance.

Do as little as possible, but as much as necessary

  • adopt a minimalist approach to conservation (which can reduce the cost of new materials)
  • consider that a building’s heritage significance can be preserved or restored but not improved by changing it into something it is not (e.g. trying to transform a modest cottage into a grand house).

Repair where possible

  • look after the original material and components of a heritage place or building as they are integral to its cultural significance
  • carry out minimal intervention to avoid destroying the heritage value
  • supplement or replace only unsound material
  • stabilise, consolidate or repair the existing structure and materials if possible.

Reconstruct only with physical or documentary evidence

  • contact Council for information on the cultural heritage significance of the place
  • research the history of your house
  • look for evidence of original elements and details to work out how to reinstate or reconstruct them
  • undertake reconstruction work only when there is enough evidence, otherwise construct it in a way that is sympathetic but easily identifiable as new work.

Undertaking conservation work

Careful planning, based on the specific needs of the building or site’s specific requirements, is essential to carry out conservation work and make alterations without detracting from the heritage place’s significance.

All conservation and adaptation projects on a heritage place should be thoroughly researched before any decisions are made about construction work.

It is not just the original house on the site that may be important. Other elements such as fences, gates, outbuildings and gardens all make a contribution to its heritage significance and should be considered before undertaking any work.

A Conservation plan is the best way to help make informed decisions about what is required.

Verandahs

  • re-open verandahs if possible and reinstate original features to help restore the house’s original appearance, increase ventilation and provide a shaded, semi-outdoor environment
  • avoid closing in verandahs as this can detract from the appearance of the house, as well as affecting interior ventilation, light and temperature
  • ensure alterations to enclose a verandah for more living space are reversible
  • use old photos of the house, or houses of a similar style and period, to restore extensively altered verandahs.

Roofing and guttering

  • conserve original roof sheeting as much as possible - sheeting usually comprised galvanised steel sheeting in short lengths, fixed with lead-headed nails and finished with scribed hip and ridge capping 
  • replace original roof sheeting if required with long lengths of galvanised sheets and cyclone screw fixings, which provide better protection and only slightly change the appearance 
  • avoid using materials such as modern, square-rib profile roofing, metal tiles, square guttering, PVC downpipes and uncoated zincalume sheeting as they detract from the appearance and cultural significance of a heritage building
  • conserve early guttering as much as possible - galvanised half round or ogee profile and later quad and downpipes were mostly round or rectangular galvanised steel, and often painted to fit the colour scheme of the building.

Roof structures

  • repair the roof by replacing existing timber members with identical-sized material where available 
  • remove timber damaged by rot or termites – cut off and dovetail (splice) a new piece in where there is enough of the section remaining for structural performance, or reinforce timber members with bolted steel plates
  • treat decayed timber with preservative and fill damaged sections with epoxy resin depending on the extent of decay.

Joinery

  • retain all items, patch or repair if possible with new timber, rather than remove and replace
  • match the original or significant components as faithfully as possible when replacing timber elements and structures
  • use epoxy resin for repairing timber structurally weakened by termite damage.

Undertaking maintenance work

Maintenance is an important part of conservation and a thorough inspection of the building should be undertaken before making any alterations. Carry out the following building checks.

Structure

  • consult a structural engineer with expertise in old buildings, if there is cracking, deflection, bulging or failure of walls
  • ensure, that in the early stages of the project, floor framing is sitting securely on supporting members and that flooring is level, otherwise new doors might not close properly and newly-laid tiles might crack.

Waterproofing

  • ensure the building is protected from water and weather by using sound roofing, flashing and damp-proofing methods which also allow the building to ‘breathe’
  • repair leaking roofs, gutters, downpipes and any other leaks in the building.

Termites

  • inspect timber stumps for rot or termite damage
  • ensure ant caps are intact and termites are not present
  • make provision for ongoing termite prevention.

Concrete

  • inspect concrete stumps for ‘concrete cancer’ caused by reinforcing bars rusting and expanding, causing concrete to crack away.

Paintwork

Masonry

  • remove paint from masonry walls that were originally unpainted
  • use a cleaning method for masonry that is appropriate for the job and condition of the surface
  • avoid sand-blasting as this is generally too harsh for most materials
  • re-point masonry only where existing mortar is unsound or where sufficient mortar is missing to cause detrimental water penetration
  • use a mortar mix that is no stronger than the original mix used in the building in order to restrict future cracking to the joints rather than the bricks or stone.

Services

  • consult a licensed electrician to check, repair or replace electrical wiring as required to minimise the risk of fire
  • install new services such as ductwork, pipework, wiring conduits, air conditioning carefully to minimise damage
  • check plumbing and drainage for leaks.

Maintenance program

Further reading

  • Evans, Ian, 'Restoration', in The Queensland House: a roof over our heads, eds Rod Fisher and Brian Crozier, Queensland Museum, Brisbane 1994
  • Evans, Ian, Getting the details right: restoring Australian houses 1890s-1920s, Flannel Flower Press, Yeronga, Queensland, 1989
  • Evans, Ian and National Trust of Queensland, The Queensland House: history and conservation, Flannel Flower Press, Mullumbimby, 2001
  • Heritage Victoria, 'Corrugated roofing; Cleaning masonry' 2001
  • Marquis-Kyle, Peter and Meredith Walker, The Illustrated Burra Charter: making good decisions about the care of important places, Australia ICOMOS, Brisbane, 1992
  • National Trust of Queensland, 'Before you start', Conserving the Queensland house, Brisbane, 1994 (guide 1 of 12)
  • NSW Heritage Office, Heritage information series: 'How to carry out work on heritage buildings and sites', 1995 

For more information contact Council’s Heritage Unit.

29 June 2014