The first edition of The Buildings of England: Dorset was published in 1972: 110 x 185 x 30mm, 554 pages. The new edition comes in at 110 x 220 x 40mm and 864 pages. The sheer weight and the impressively bloated dimensions restrict the book’s utility. It doesn’t fit into any pocket other than a poacher’s so is fated to be a deskbound encyclopaedia rather than a portable guide.

What has happened to Dorset in the intervening four and a half decades to justify such distension? In 1972 the Jurassic Coast had not been designated as such and the county had yet to become a de facto architectural laboratory in which whimsical experiments would sully the countryside, contaminate towns and disfigure the coast. These experiments may be stylistically disparate but they are bound together in their creators’ determination to lurch headlong into the past. The work ranges from pastiche to what might be called trashtiche, from the very approximately simulated Old Englishness of the Prince of Wales’s wretched new town, Poundbury, through some arch exercises in Arts and Crafts revivalism to a coarse neo-modernism that has spread like a rash from Sandbanks and Canford Cliffs to an already defaced hinterland.

Michael Hill, who has revised and updated the 1972 edition that John Newman and Nikolaus Pevsner coauthored, writes of Poundbury: ‘To walk through such a large settlement and meet no reflection of anything that has happened, architecturally, through the Victorian years, or after, say, 1914, is to experience a profound sense of displacement.’ That’s one way of putting it. It’s best regarded as an unintentional folly or as a fantasy guying various schools of architectural illiteracy. Even after twenty-five years this ever-expanding suburb of Dorchester shocks when it comes into view. Its site is crassly chosen. Dorchester used to be a town with unusually legible boundaries. No more. And then there is the matter of Poundbury’s relationship to Maiden Castle, the greatest Iron Age hill fort in Britain, only half a mile away.

Maybe its illusionism does not go far enough: cars should be banned and its residents obliged to dress in late-Georgian costumes, submit to late-Georgian dentistry and enjoy the scent of late-Georgian plumbing. It’s a monument to facadism, exterior decoration and the capacious dressing-up box of previous styles. So it is odd that Victorian models are proscribed there, given that epoch’s mastery of making the past the present. It’s odder still that parts of Poundbury derive from a sort of volkisch Jugendstil.

It has, of course, occasioned deferential copyism. ‘Traditional homes’ are evidently not restricted to Dorset. But the ‘traditions’ followed in the county are arbitrary and, it goes without saying, entirely bogus. Why on earth should a more-or-less exact copy of Voysey’s house in South Parade, Chiswick, be built a hundred years later in Shillingstone, between Blandford Forum and Shaftesbury? Hill omits this particular aberration but he does include a lame attempt to ape an Arts and Crafts butterfly-plan house – always a mistake. He describes a building by Baillie Scott as ‘coyly complicated’, which is just about all one needs to know of the precious tweeness of much of the Arts and Crafts movement, let alone its copyists. He doesn’t, though, do himself any favours by describing a turret at Guy Dawber’s remote downland house, Ashley Chase, as ‘naughtily curved’, an epithet that is itself coy.

A gauged sort of retrospection is manifest in the Nash-influenced work of Robert Adam (the very much living one) and at Anthony Jaggard’s camp, theatrical, fanatically crenellated Bellamont, another remote downland house that is an inspired invention rather than a reproduction. However, these are exceptions, qualitatively and idiomatically. Running Poundbury a close second is the Lombard School of subarchitecture. Lombard is a 1980s City acronym: Loads of Money but a Real Dickhead. Branksome Park and Sandbanks are England’s California. They are the Lombard playgrounds par excellence. They form the centre of a breed of neo-modernism, the primary purpose of which is to express wealth and the secondary purpose of which is to express more wealth. This is far from the insipidity and cautious good taste of Poundbury, which causes offence by trying not to do so. This is far from the earnest ethical programme of modernism too. It is, rather, turbo-charged vulgarity, exciting because it’s as energetic as cheap music, and about as satisfying. Counterintuitive features are so much the norm that they become intuitive. Turquoise glass is de rigueur (this month). Blue pantiles are signature tiles. The gardens are heirs to Compton Acres in Parkstone, a place, in the words of John Betjeman, of ‘unexampled and elaborate hideousness’. Wacky angles and slipways abound. The more expensive the materials that can be crammed onto a facade the better. There is no word for restraint in the Lombard lexicon but there are a hundred for dosh.

But these domestic excrescences, together with countless other indignities visited on this blameless county, do not account for this new edition’s bulk. Nor do Bournemouth and Christchurch. In 1972, shortly before the county boundary changes, they were still in Hampshire. And that, so far as the Buildings of England is concerned, is where they shall remain. The predominant reason for this growth spurt is the amount of detail that Hill brings to the revision, detail derived from the increased professionalisation of architectural-historical scholarship. That in turn presumes, accurately, a more knowledgeable, more architecturally literate constituency of readers than existed forty-odd years ago. This constituency has been broadly schooled by the Buildings of England series: like all great works it has created its own audience. The gulf between this edition and its predecessor is akin to that between a great mansion such as Eastbury, say, and Vanbrugh’s initial sketches for it. Pevsner’s incomparable gifts to his adopted country were not merely the volumes that he himself wrote but also the template that he created and the example that he provided. He set in motion something as vital and as capable of infinite expansion as the OED, a juggernaut of voussoirs, attributions, dates, crisp judgements, minimalist prose and feigned impersonality.

In the 1972 edition the descriptions of sacred buildings were written by Pevsner himself and those of secular buildings by Newman. With one exception, Pevsner chose his collaborators well. Newman, who also wrote both of the excellent volumes on Kent, is a discreet presence but a presence nonetheless, with a felicitous turn of phrase. He begins his entry on Upton House, near Poole: ‘An early c19 stuccoed villa in a small, somewhat rank, park.’ Hill amends the entry, perhaps corrects it, certainly increases its length, yet loses that ‘somewhat rank’ – which is what makes it. Of course, it is possible that the park is no longer rank and that remedial gardening has quashed a memorable phrase.

Pevsner wrote that, although Dorset was reputed a ‘house or mansion county’, its churches caused him to realise ‘how very much one has enjoyed’. Hill takes this as a challenge, or at least a cue to prolixity. The result is that, like the very earliest volumes, there is a marked ecclesiastical bias. The imbalance in the early volumes was based on the traditional hierarchy, whereby the sacred was placed higher than the secular. It was gradually corrected by Pevsner’s collaborators. Here, the entry for the minster church of Wimborne is five times the length of that for Eastbury, the third greatest house built by England’s greatest architect. That for St Mary Magdalene at Loders, near Bridport, is twice as long as in the first edition. The nearby strip lynchets, however, now go unmentioned. Perhaps they no longer count as architecture. Perhaps they have been ploughed over. Perhaps they have been overlooked. But in his foraging ecumenicism Hill has found in that village a Methodist chapel and has included it. Indeed the book is weighed down by these joyless off-the-peg sheds. They are seldom of much architectural worth. It is hard to believe that in Verwood, West Moors and Ferndown there is not a single domestic building to be noted. These are places of exemplary 20th-century sprawl on the heathlands to the north of Bournemouth. They are lazily reckoned to be characterless. No place is characterless. They may not be susceptible to the architectural scholarship in which Hill excels, but they are susceptible to the scrutiny of a topographically inclined eye.