The following would seem to indicate that the landlord just thinks of a figure and then doubles it. Narendra Patel, who runs Cosmos Newsagent in the Tottenham area of north London, must get the jitters every time his rent review is due.

He is currently paying £10,750 per annum for a 400sq ft shop and residence (non subletting, full repair and full insurance). He recently received a letter from his landlord’s surveyor saying that the new rent would be £18,000 from June 21.

The problems, says Narendra, date back to 1993 when he was paying £5,000 a year. His landlord asked him to pay £12,500 and then £15,000 and finally £17,300 for the same year.

Narendra’s surveyor suggested the property as a whole should attract a rent of £7,500. As there was such a huge difference between Narendra’s surveyor’s figures and the landlord’s surveyor, the matter went to court and the new rent was duly fixed at £7,500 (£6,000 for the shop and £1,500 for the residence). The reviews had previously been annual but the court set the next three rent reviews for five years, five years and then four years, starting in 1995.

In 2000 the landlord quoted £15,000. This time the matter only reached the arbitrator. The landlord agreed to £10,750 which Narendra is currently paying. But, if you remember, the new demand represents a huge hike to £18,000.

What mystifies Narendra, and me too, is why two qualified surveyors can come to such wildly differing recommendations. As he says: “The process of hiring surveyors and solicitors is quite expensive. Are there standard procedures for the way rent should be calculated?”

Rent reviews are meant to reflect local market values. A similar property trading opposite Narendra has been set at £14,000 and the tenants are negotiating. In Narendra’s case it just looks as though his landlord tries every time to get a maximum return which forces him to spend money on negotiating it down to an acceptable level. “Why can’t the Government set a ceiling on it?” he asks. “If I knew my increase was going to be, say, 20% I would know where I stand. Businesses can go bust because of this.”

Indeed they can. The Contact Centre for the Royal Institute of Chartered Surveyors (RICS) runs a Rent Review helpline which is part of its Disputes Resolution Service. A spokeswoman said: “We can appoint an arbitrator in cases like this – an independent expert.”

But there are apparently no restraints on what landlords can charge.

It might be a pain in the wallet every time but it sounds as though, in Narendra’s case, the surveyor is getting results and earning his money.

RICS operates a free rents and rates helpline. Tel: 0870 333 1600.