Here are twelve tips to help you look after old buildings and structures, and help preserve Australia's heritage. Before you buy an historic property, make sure that it is generally suitable to your requirements in terms of size and arrangement. Sometimes people buy buildings because of their historic charm, only to completely alter them.

In fact, if you need an addition larger than the original building, or like open-plan living, you may have to alter an old building so much that a lot of its historic charm will be lost.

The following twelve tips will help you to repair and renovate old buildings in a sympathetic manner.

Look before you leap

Quick decisions made about old buildings often lead to unforeseen complications because ways of designing and building were different in the 19th and early 20th century. There may also have been changes made that are not obvious.

Take a good look at, the building and try to discover the, original room uses, how the structures and finishes were actually built, and determine the extent and construction of subsequent changes.

This information could well change your initial ideas about how to maintain the, building and what changes you wish to make.

Sometimes, on reflection, past changes and even the contents of old buildings are sufficiently interesting to preserve and repair.

Do some historical research

Old records might provide inspiration on how to restore or renovate, and also identify rooms and features that you would like to keep unaltered. For example, old photographs often show decorative roof and verandah features long since removed. You may later regret changes made without understanding the building's history.

Maintain roofs and gutters

The major cause of deterioration in old buildings is water damage from leaking roofs and gutters and faulty downpipes and drainage. The old soft brickwork, renders and plasters are easily saturated and paintwork quickly chips off and the timber begins to rot. Keep water out and away from buildings by regularly checking the gutters, downpipes and drains. Saturated ground promotes rising damp and even structural subsidence.

Temporary unsightly repairs are preferable to allowing water penetration for even short periods.

Use matching and traditional materials and profiles

Many new materials and the profiles and sizes in which they are supplied (for instance, new aluminium windows) are both unsightly and of the wrong proportions. For example, the profile of gutters generally supplied today is not the same as that used in the Victorian and Edwardian periods. However, suitable materials can still be made or are available from specialist suppliers.

Some modern materials are even technically incompatible with old buildings. Zinc-aluminium coated steel, for example, cannot be properly used with lead or solder.

The use of traditional materials and profiles is not only technically preferable but generally looks the best anyway.

Avoid over-restoration

Doing too much restoration work sometimes removes the attractive quality of old buildings. Usually there has been a succession of alterations and surfaces have developed patination due to use and weathering. These all provide a sense of age and previous occupation and some can be considered 'honourable scars'.

Keep as many signs of age as is practicable.

Beware of cement and concreate

Most old construction employed relatively soft materials such as stone, brick, lime plaster and compo render. Concrete and strong mixes of cement mortar are usually incompatible with 19th and early 20th century buildings. Use of them can lead to cracking walls, drummy render, uneven settlement and also permeability problems (see tip number 7).

Internal lime renders, external compo renders and brick mortars were lime-based, and while a limited amount of cement can be used, this should only be done in external, highly exposed areas such as parapets and chimneys.

It is best to seek professional advice on appropriate lime-based mortars and renders before undertaking such work.

Allow floors and walls to 'breathe'

Most old walls and floors allow the passage of small amounts of moisture rising from the ground to escape because they are soft and porous. In wet periods walls absorb moisture which dries out again on sunny days. Attempting to 'seal' walls against damp penetration or rising damp usually exacerbates the problem by damming up moisture within the walls.

Applying oil sealers, membranes or cement render to walls with damp problems will merely drive the water higher. The water source needs to be cut off by a damp proof course or better drainage.

The use of lime plaster (inside), compo render (outside) and acrylic paints will allow old walls to retain their natural porosity and respond to moisture in an appropriate way.

Where possible the use of concrete floors should be avoided as this can also drive ground water into the walls.

The deterioration of timber flooring is usually due to inadequate ventilation in the subfloor areas. Unblocking vents, or adding new ones, will help dry out the subfloor.

Avoid 'cure all' wonder products

There is always someone selling new wonder products that solve all problems. These are often expensive and seldom solve any problems at all in the long run, and may even cause damage. Traditional matching materials are usually best. Test any new materials in real conditions before using them on large areas or in critical locations.

Avoid mock-heritage reproductions

Designing buildings in historical styles has always been popular, but to build a reproduction building or extension beside an old building can produce an historical fraud. Often the proportions and materials of such buildings detract from the original. Small or detached additions will usually fit in better. There are many guidelines published by local councils on how this can be done.

Try to make larger additions sympathetic in location, bulk, proportion, scale and materials without copying historical styles.

Don't make the building redundant

Old buildings are best maintained and appreciated by using them. The active use of an old building with sensitive alterations is preferable to having a perfectly intact building with no use.

When redeveloping or renovating, locate useful compatible functions within the old building so that the building has a new life and a further history. This may mean some changes, but this may be a better option than creating a useless, historic building. Such changes should, if possible, he reversible.

Use sympathetic colours

Older buildings are often more appealing if their colour schemes relate to their period and style of construction.

Paint scrapings may be analysed and used to identify original colours. Many large paint companies now produce a good range of heritage colours.

Question destructive building regulations

Making a building safe and healthy and protecting it from fire damage is important. However, it is worth discussing building regulations with your local council as it may be possible to vary some regulations to minimise any destructive requirements.

Further information and advice

There are now many sources of information about caring for old buildings and structures, including published books, booklets and pamphlets available from local councils, State/Territory heritage agencies and National Trusts. Some councils have heritage advisors and there are also specialist consultants such as architects and engineers for large and difficult projects, or where special climatic conditions occur. Some buildings attract financial assistance (contact your local council for information).

NATIONAL TRUST: (02) 6247 6766

AUSTRALIAN ICOMOS Inc. (03) 9251 7131

The pamphlet was a joint project of the Australian Council of National Trusts, and Australia ICOMOS with the assistance of funds made available by the Commonwealth of Australia under the 1995-96 National Estates Grants Program. The intellectual property in the pamphlet is held by the Commonwealth of Australia. The views expressed in this material do not necessarily represent the views or policies of the Australian Heritage Commission.