What do you do when your chicks have grown and flown the nest?

We all think it will never happen - and then old age rushes at us ever faster. What once, in heady youth, seemed like dreary questions about superannuation and retirement become real and pressing.

Questions like: how do I maintain a reasonable standard of living in this big house without the wage which once paid for it? And do we even need that big house to rattle around in now that the chicks have grown and flown?

To shed some light, two of the country's experts have just released the 2nd edition of their book of do's and don'ts for downsizers.

Noel Whittaker, who has published 20 best-selling books of financial advice and answers reader questions every week for this newspaper and the ACM network, has co-authored Downsizing Made Simple with Rachel Lane, who has a master's degree in financial planning and specialises in financing aged care.

Speaking on the sidelines of a conference in Canberra this week, they talk as one when asked what someone approaching 70 should do.

"The most common downsizing regret is that they don't make the decision sooner," Ms Lane said, with Mr Whittaker echoing it.

Downsizing Made Simple takes people through the necessary decisions and choices.

Mr Whittaker poses unpleasant but essential questions for people on that cusp of old age: "If you are a couple and you have a disability like a broken arm or whatever, can your existing house handle that? What if you need care?"

If your answers are worrying and you need to ask "Where next?", they go through the options, including strata title homes, granny flats, collaborative housing and retirement communities. The authors take you through the pros and cons and the must-dos.

Their best advice often includes: get good advice. After all, everybody's needs and desires differ. Some have family and some don't. Some retire early and some seem to want to work until they drop. Lawyers and financial advisors specialise in the detail.

As Mr Whittaker puts it: "There are a multitude of factors that determine how much anybody would need to retire comfortably.

"These include the state of your health, your life expectancy, your spending habits and what level of age pension may be available to you. Inflation is a huge factor."

He says this last factor - inflation - is huge: "Suppose you are 50 now and decide you will need $70,000 a year in today's dollars to live on if you decide to retire at age 65. If inflation was 2 per cent that would equate to $94,300 a year, but if inflation increased to 4 per cent that figure would leap to $126,000 a year."

On downsizing, he emphasises that you need to assess your future needs and possible out-goings. Read the small print. Take advice.

"No matter what form your new home takes - whether it's a freehold, strata title, leasehold, licence, or a granny flat arrangement - you will need to sign a contract. Your contract spells out your rights, responsibilities, and costs. Take legal advice and make sure you understand it."

And he warns of potholes: "Of all the downsizing options, granny flat arrangements can be particularly complex, as they involve family, are not necessarily on commercial terms, and if it goes wrong the whole family can be affected."

Above all, he says, "Retirement can be a jungle of decision-making. What sort of assets to invest in? How long will your money last? Are you eligible for any age pension? Is downsizing right for you? How much should you spend now, and how much would you like to leave to your kids?"

He and Ms Lane offer routes through the jungle - but it all depends on your own needs and wants. It's your choice.

The pair's sessions on Downsizing Made Simple for RSL LifeCare continue on Thursday morning at the Canberra Rex Hotel on Northbourne Avenue.