Things came to a tipping point last week when a blind fell on my head. It fell on my head as I was grappling with it in order to do some writing. I was trying to do some writing because that is my job. I perform my job in my home office, which was designed by a moron who thought writing under a glass ceiling would be delightful. It is, unless the sun shines, at which point it is impossible to read a single word on the computer screen. This happens fairly often, hence the need for a blind, hence my irritation when it fell down. Who was the moron who designed my office? Why, me, of course.

Most people would love to work at home. On the face of it, having a home office is something to envy. No commuting. No clock-watching managers. Endless cups of coffee, optional nudity, a dog at your feet, a child at your breast. That’s the upside.

The downside is that you will miss out on all the stuff you get in an old-fashioned office: the nice stationery cupboard, the gossip, the camaraderie, the chance to escape your family, eating out for lunch – and an office manager to mend the blinds. Also, chances are that you will probably have proper furniture to hand. You will not be sitting on a Lloyd Loom chair at a low-slung coffee table, a rickety Habitat desk, or (as in my case) a horizontal slab of plastic. You will have proper lighting, a Powwow water cooler and an ergonomically designed, kidney-shaped leather-topped desk with beautifully smooth sliding drawers. You will have an Anglepoise. Hell, you will have air-con.

Whereas my office, which could easily double up as a small conservatory, is freezing in winter and roasting from spring onwards, even when the blinds are all down. It’s too small, and cluttered with an assortment of papers, toys, postcards, pictures, pets and children. Now Mr Millard wants to work in it, too.

Why can’t you go out and work in the garden shed, I ask him. Plenty of other people do. Did you know that the Suffolk-dwelling, millionaire bestselling author Louis de Bernières works in a shed? All right, last year it was burgled and his laptop, containing the first chapters of his latest novel, was pinched – but still, if you can write bestsellers in it, it’s a workable shed. Dickens wrote in a shed. George Bernard Shaw wrote in a spinning shed. His was in the grounds of his home in Hertfordshire, and as the earth revolved, so did the shed, so the great man could catch the sun all day.

Sadly, Mr Millard isn’t made of such stern stuff as Louis or GBS. “I tried working in our shed,” he murmured. “It’s too hot. It’s too damp. It’s full of spiders and has no electricity.”

And so a team of Shed Consultants came to assess our garden for shed potential, and told us that with a bit of digging, they could build a two-tier shed that would give a “mezzanine” area as well as a ground floor, at a cost of about £10,000. This would include plumbing, electricity and insulation. Planning permission? The team didn’t seem to think this would be a problem, although as it’s a permanent structure, we would obviously have to get it. You can also get ready-made log cabins, I told Mr Millard: Wickes does one with an adjoining terrace for £5,999.

At which juncture, Mr Millard’s golfing buddy, a Hollywood screenplay writer, was given an option on a working shed by his wife for his 50th birthday. And he discovered that a quote of £26,000 was more like it. His was a lot bigger. Naturally, Mr Millard now finds he, too, wants a £26k shed for his birthday. So, we’re back to rethinking my office in the house.

What are the basic necessities of the home office? A discrete, quiet area. Good mobile-phone reception. WiFi. Light and, as important, shade. Can the costs be claimed against tax? Well, you can start racking up claims for electricity, heating and one room’s worth of mortgage, if you really want to. The only problem is that when you come to sell, the room you claim is used solely as an office will not enjoy the same exemptions from capital gains tax as the rest of your home.

As a result, you might end up coughing up more in tax than you claimed for the office in the first place. What about your stuff? Computers, phones, stationery? You might claim for a proportion of use, but that’s about it. Tax relief can be achieved for expenses incurred “wholly, exclusively and necessarily” in the performance of work, but the Inland Revenue might doubt that your landline is only ever used for work, and you would have to prove your computer is never used by the kids for Club Penguin.

In essence, it comes down to this: if you can be bothered with the extra work, the tidying up and the imposition of having an office in your home, great. If you can’t, then maybe you still belong in the land of David Brent. And put £26,000 sheds right out of your mind. That seems too high a price to pay for something that is not even bricks and mortar.

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