'I don't mind spending money on nice dinners or family holidays'

He recently helped launch the 2016 RIAI Simon Open Door campaign - in which architects nationwide will offer one-hour consultations to the public in return for a donation of €70 to Simon Communities Ireland. The campaign takes place on May 14 and 15 - visit simonopendoor.ie for details.

What is the most important lesson about money you have learned in your career?

As I run my own practice, I have learned to pay myself the same salary every month, because for every good month the business has, there can always be a bad month. I also think we became a little bit of a nation of consumers, so I now try to buy what I need rather than what I want.

What's the biggest financial mistake people make when doing up their home?

Scrimping on the important things such as insulation, windows or permanent finishes like floors - to keep a budget for the big TV that will be out of date in a couple of years. Invest in the things that you can't upgrade or change in a few years.

Apart from property, what's the most expensive thing you have ever bought?

I don't buy expensive things. The most expensive things I buy would be family holidays with the kids - but they create wonderful memories. I don't mind spending money on experiences like nice dinners and holidays - rather than things. I'm not into labels. Good taste is good design - it could be €25, but if it is well designed, it doesn't have to be expensive. Family holidays and nights out are where my money goes.

What was your worst job?

Scrubbing pots in the Grand Hotel in Malahide for two summers. My brother wanted to be a chef so my Dad wanted his passion tested and got him the worst job in a hotel - and he landed me a job in the same place. I never forgave him.

What was your biggest financial mistake?

Not moving house two years ago. We need a bigger house and now prices are starting to go beyond our reach.

What was your best financial killing?

Our first house, a small fixer-upper in the city when nobody was buying fixer-uppers. We spent every weekend doing up the house ourselves for about six months and sold it a couple of years later for a good profit when the market had caught up with the benefits of living in the city.

Do you use any money-saving apps?

No, but my 11-year-old daughter manages to get access to everything for free online - so she is teaching me now.

Do you have an Android or an iPhone?

An iPhone - an old one though. As a designer, I love all Apple products.

How much is in your current account?

I have no idea - I still go to the cash machine with my fingers crossed.

Have you ever made an insurance claim?

Only on the health insurance for the kids. I think Irish people are scared of claiming, in case premiums go through the roof.

What was the last thing you bought online?

A gym mat for my 11-year-old daughter. I'm not great at buying online. I like to hold things before I buy them. There is nothing better than having a good relationship with a knowledgeable retailer. I think it's something we will miss in a few years.

Is the mortgage fixed, variable or tracker?

We are one of the lucky ones on a tracker.

Would you buy Irish property now?

I'm not sure. I'd be cautious as supply is low at the moment, so we may be in a bubble situation - if you find somewhere you can afford, buy it. But don't panic-buy.

Do you pay in cash or card?

Card all the way, even for a loaf of bread. I'm the annoying one in the queue in the supermarket. If I have the cash in my pocket, I just spend it on things I don't need.

Do you ever haggle?

All the time, I will always ask for a discount - even on a pair of jeans. You don't always get it but you never will if you don't ask.

Are you better off than your parents?

In some ways I am - and in a lot of other ways not. Both my parents worked in the public sector so had a guaranteed income for their lifetimes and good pensions. I may have had a couple of better years financially but when you run your own business, you are only as good as your last project. There is a lot to be said for job and financial security.

You can tweet Dermot Bannon @dermotbannon