With site-specific commissions there is always a brief, which I try to ignore if possible, and to just work with it and see if there is a problem. The site-specific work developed out of my interest in spaces and architecture – architecture as form and the social activity in the space.

For a while I found it difficult to work on canvas or support – it’s probably a character thing as my brain starts working when I can respond to something – people, a story, a book, a space. Working on canvas I found too difficult. The surface is too soft. That’s why I like working on a wall. The hard surface is beautiful to draw on.

For me, an important aspect is that the work does not start when I begin painting, but before, when I am travelling to the space – and I try to take in as much information as I can but my own story also starts. There can be things from art history – but also things from daily life that influence what I am doing. The work doesn’t end where the paint ends, but is about the whole space. It is something performative – for example where there is a room and I paint a wall pink, the viewer becomes part of the work – an interaction between the viewer and the work.

Site-specific works often work with the memory. You have an eye in the back of the head as well. When you see an orange on one wall and then green on the other, even if you’ve only seen it for a second it’s in your brain. When something is site specific it is so different from looking at a painting, which you can see in one go. You have to walk around. It’s not an image. The viewer becomes an integral part of the whole work because it’s not possible without that.

I start to make sketches, spending a lot of time wandering around. Then I make rough sketches without using colour. The process is not an active design process, but an emptying out of the head where I try to make a connection with the space, where I become like a medium. Very often I get first ideas and then dismiss them again. Usually I leave and then don’t know what I’ll do and get a moment of despair. Often an idea comes later when I look at my sketches. I need time, distance. A train journey, a day or two… I then start to draw.

Working with pencils, following up ideas – most of which get chucked away. After I made the decision on what to do, I went to my Berlin studio for a week, which is very clean – the opposite of here – and I worked there and at the end I felt ready to start.

Art has the freedom to be completely useless. You probably need a certain selfishness. David Bowie said that all his best work was when he was completely in the work being selfish. When you’re in the studio being a bit crazy, after that period, the two things come together. You do not have that strange discrepancy when you work on a painting or drawing. These commissions get their own life, meeting people, travelling there.

You design something and solve problems with public art commissions. When you respond to something you have a responsibility – you are not entirely neutral. You have to design something that has to function. There is a social use that is fixed to something that is very different to a gallery.

Abstract works for me are so much more real than so many realist paintings. For me, abstraction and reality belong together – I always have problems when people divide these two things. People are inspired, looking at work, making work – it’s kind of a circle. On the one hand you respond to something that is real and then in the studio something completely abstract and then bring them together.

If you have a staircase that is completely white and you add colour, it doesn’t change the function but it does completely change our experience of going up and down the stairs.

I am not interested in abstraction as a theory model. I’m not dogmatic about it. I get irritated when it is being fitted into a set of rules. I don’t see my work as opposed to figurative art. It’s the same thing with music – you respond to a more abstract quality. For me it is completely real.

It was quite important. I loved Bach. I went to a specific school for artists and musicians. I loved to play the piano and had lessons in piano and flute for at least ten years from around the age of seven. I did lots of painting compositions after music when I was a student. Classical music was quite important, particularly as a teenager, and especially Handel. Music can transport you into an abstract space. It is a similar way of thinking: dismantling reality and putting it together in your own way.

As a child I created big villas. I was always interested in architecture, in the private and domestic space. I always enjoyed maps and ground plans – they give you the freedom to imagine what it could be.

I looked at thousands of architectural plans as a child, but for me it was the starting point for a fantasy. For a long time architecture inspired me more than art. When I get really excited by space it’s with the buildings that have the dimensions of a private house. I see a house as an extension for our body, nearly a portrait of someone. It’s an extended body. The kind of architecture you grow up with. I grew up in a little market town and probably knew every building site on the town. I was very much a loner. I played with dolls and imagined all these spaces for them.

At the time they were building all these 1970s bungalows. These were all architect-designed – different to a Barrett home in England: architect-designed modernist spaces. This moment of imagining things is one of the main reasons I became an artist in that I was never really interested in reality. When you get your head into a book you create a different reality. There was one house I looked at all the time. I was fascinated by the ground plan, and after it was finished I went with my parents to see it, but nearly cried as the reality was so disappointing. I later did a project called ‘If I had grown up elsewhere’. The finishing of something as an architect did not interest me. It’s the point where it is not ready.

The local church in Günzburg (the Frauenkirche), where I had Holy Communion, was built by the same architect, Dominikus Zimmermann. It was the testing out for his masterwork at Die Wieskirche. The spaces of Baroque churches had quite a big influence on me: I grew up in a narrow-minded environment and architecture was a way out of that.

I grew up in a provincial, quite homophobic environment. As a child I was obsessed with green eye shadow, escaping through makeup. Transforming as a child was an escape – I didn’t realise as a child what that meant. In Günzburg there were wall paintings that were quite tropical with really amazing trompe l’œil. Baroque paintings are all illusionary, a bit fake and theatrical, but it’s reality in that moment. It’s like being transformed into some sort of cloud of space that’s real.

As a student I was always saying I hated Baroque because I loved the Bauhaus, until one of my painting tutors said I was a Baroque soul. Only later I understood what he meant – dealing with painting as a different kind of space – doing wall paintings in spaces adds a different kind of space – these layers.

Coming from Bavaria I responded to the light and very specific conditions in landscape when growing up. Kandinsky and the whole Bauhaus thing was probably the biggest influence for me. The Bauhaus was the first art movement that influenced me as a student, after my childhood interest in architecture and plans. There are links to the ground plans of imagined houses I did as a child.

When a student in Aachen I was not a painterly painter – I was always on the edge with design, theatre, and architecture. In my first degree I did a bit of everything. And the Bauhaus I felt the most in common with – I always like the traditional world of Gestaltung (design). The Bauhaus was always good breaking down categories – designers as theatre people and I like the whole political social aspect – beautiful simple mass production. I always responded very much to colour. As a student I did my dissertation in art history on Oskar Schlemmer’s Triadic Ballet.

I couldn’t decide the way I wanted to go – I would go more to the theatre than to the museum. At the RCA I started to bring all these elements together and with site-specific projects could combine different interests.

Ben Nicholson was a big influence. I felt much closer to Nicholson than lots of people from Germany. This probably goes even so far as the question of why I enjoy being an artist in Britain more than in Germany. With Nicholson, it was the form. I came across him in the second year of my first degree. I was drawing all these corners and always trying to make an abstract composition and my tutors said I should look at Ben Nicholson. It wasn’t colour, but the geometry and shapes, the drawings that are not abstract that were quite influential. It’s so much more playful – so English – in Germany it was often seen as more strategic.

In Dusseldorf my tutor Gerhard Merz tried to rip the personal out of us, because there was the idea that everything had to be the perfect white cube. I was always interested in the imperfection – not the intention to change it, but to start from there and include it into the work.