Over the next five weeks, Canada Post will release 10 commemorative stamps to honour the nation's 150th birthday.

The first stamp, unveiled Thursday, features a prominent Montreal landmark: Habitat 67.

The revolutionary housing complex, which sits on an island in the St. Lawrence River, was originally designed for Expo 67

Moshe Safdie was the young McGill-trained architect behind Habitat 67.

He has since won dozens of awards for his work around the world.

Safdie now lives in Cambridge, Massachusetts, but he was in Montreal Thursday morning for the unveiling of the stamp.

Here's a part of his conversation with CBC Radio One's Homerun host Sue Smith.

The following transcript has been edited for length and clarity.

How does it feel to have your work on a commemorative stamp?

MS: I'm on a high. First the sun came out just as the ceremony began, so the building looked beautiful and it was extremely moving. We were surround by residents, some of whom have been living in Habitat for over 50 years. It was just all very touching.

Take us back. How did you get that commission?

MS: I had developed a thesis about housing at McGill University where I graduated in '61 and in 1963 when Expo was announced, my professor came — I was then working in Philadelphia — and said we're going have the world's fair. How about coming and heading the team that will design the master plan? I was thrilled to accept but I said I have a condition., I'd like to develop my thesis as one of the central pavilions of the Expo. And his response was if you do it on your own time, why not? So it was 6 months of probably 16-hour days, doing the master plan daytime and developing the plans for Habitat and then lo and behold, Expo management and three levels of government approved it, funded it and the rest is a fairy tale.

How old were you when this all happened?

MS: I was 24 when we proposed it and 29 when we completed it on the opening of Expo 50 years ago today.

That's incredible!

MS: It is incredible and when you think about it, would a young architect who's never built a building, recently arrived immigrant who proposed something so radical today, [involving] three levels of government, have a chance? That's an interesting reflection. So my message today was, 'Give youth a chance.'

Of course you were young and sounds like you were pretty confident, but it looks crazy now…It was very audacious at the time.

MS: It was audacious then. It was very controversial. People forget how controversial it was. A lot of people attacking the building as a silly idea. It is probably as fresh and relevant to the architectural profession today. Students are really into it today, maybe even more than 50 years ago. So in some way we can say it's 50 years old but it's time is yet to come.

What was your vision behind it? What were you trying to accomplish?

MS: I had gone on a travelling fellowship sponsored by the Central Housing and Mortgage Corporation to study housing in North America...and I came back saying, 'Those who can go to the suburbs want the single family house and those who can't go to high-rise public housing which is not very livable.' We haven't really cracked the way of designing apartment buildings for high-density cities which is conducive to family living.

So I came back and said for my thesis, I'm going to try and invent a new building type which does just that. The motto was 'For everyone a garden.'

Every apartment is a house with a garden open to the sky, access by streets, open to the weather. It's like a house, living in the city.

Was it designed as social housing? Because the criticisms I've read said it was designed for social housing, but only the rich could live there.

MS: It was not designed as social housing. It was a world's fair. It was designed as housing for middle-income families. For most families then, who were going to live in suburbs, these were middle-income families and they were not choosing to live in apartments if they could help it. So Habitat was to show that there is housing possible for the great majority of people who might one day want to live in cities. Today it's full circle. They want to live in cities but can they afford to?

What's it like for you to come back here to Montreal?

MS: It's always coming back home and it's always very sentimental. My family's still in Montreal and my mother who passed away 3 years ago would bring me [to Montreal] quite often. I wish I had more work in Montreal so that it would be more frequent. But it's always like homecoming and very sentimental. Now around the 50th anniversary, it's exciting.