Doon Mackichan plays Cathy.

Describe Two Doors Down...

It's real enough to be recognisable but bonkers enough for comedic licence - Two Doors Down is proof that big things do happen in small places. It's a comedy about domestic life and a group of neighbours who live side by side, invading each other's lives. It's all about fish in the fridge, washing machines and fights in the garage.

What makes Two Doors Down stand out?

The writing. It's written really well for women and all the funny lines are written equally for both sexes. There was one day we were filming a scene in the garden which featured the four female cast members [Doon, Arabella, Elaine & Sharon], a female producer, a female camerawomen and a female first Assistant Director - that was an all-time first for my career.

What's your character, Cathy, like?

She's a wannabe Pussycat Doll. She lives in fantasy world, she's slightly hysterical and uptight but she's sort of loveable and flawed in equal measure! Not 'floored' but 'flawed' - although in saying that, she's often floored because she's drunk a lot of the time.

What's her marriage to Colin like?

She's got a great relationship with Colin [Jonathan Watson], which is her redeeming feature. He keeps her feet on the ground as much as he can. Believe it or not, without Colin she'd be all over the shop - well more all over the shop than she is already. They are one of those couples who genuinely love each other. They've got big ideas and are forever surfing the net, looking out for the next big thing. Cathy totally buys into the celebrity culture and wouldn't think anything of booking a holiday to Capri because she read about a celebrity going there.

Would you describe Cathy as the neighbour from hell or heaven?

She's the neighbour from purgatory - somewhere in between heaven and hell! In so many ways she's a really lovely person but she can also be a complete nightmare. She's not horrible with it, she just lives in a bubble of her own.

Being Cathy's friend is a bit of a rollercoaster ride - you don't quite know what you're going to get when she knocks on the door. She'll either be in tears or having a manic joyful episode because she's booked her latest holiday.

How does she feel about her neighbours?

She thinks they're very lucky to have her, that she's the shining light of the street. She absolutely believes she's a great asset to her neighbours but the truth is she would be absolutely lost without them.

She likes to drop in unannounced on Beth & Eric - why?

I think Beth's like the mum she doesn't have and the Bairds represent a solid regularity she doesn't have in her own life. She doesn't work, Colin looks after her like a princess in the castle so she needs her neighbours to feel 'normal'. Beyond shopping and visiting her neighbours, she doesn't tend to go out much or very far, so her neighbours help Cathy break up the stir-craziness of her life.

How does she feel about Christine?

Well she certainly doesn't like Christine as much as she likes Beth. She finds Christine a bit of a pain to be honest and she's a bit disgusted by Christine's lack of style and love of tracksuits. A lot of the time, Cathy looks at Christine and thinks, how do you even dare to come out of your house looking like that?

Cathy likes to hold court and Christine is a threat to that. They don't dislike one another, they tolerate each other. If Beth was ever on holiday then Cathy would turn to Christine.

What was it like returning to Scotland for the shoot?

Bloody fantastic. I did a bit of research into my ancestors and they're all from Ardnamurchan in the west coast, so I felt like a had a real affinity with the area. I took part in the Lamlash Splash where you swim from the Holy Isle to the Isle of Arran - I love wild swimming.

We used to rush off to Loch Lomond which is near the BBC Dumbarton studios as the sun was setting. We filmed in a studio which had no natural light so as soon as the day was over we'd all drive off to Loch Lomond to go wild swimming, taking whoever was stupid enough to agree to come with me.

You've got a new face in Two Doors Down with Elaine C Smith joining the cast...

It was an absolute joy of joys working with Elaine. She has such a lot of experience, she's a theatre actress, a comedy actress, a dramatic actress - an all-round superwoman and I love her. She gets the giggles a lot on set and the trouble is I can't get them, because once I do I can't stop. Everything just comes crashing down when I start laughing.

Finally... does everybody need good neighbours?

I think your neighbours are always there to challenge you. I've moved quite a lot in my life so I know the importance of good neighbours and curtain-twitchers!