The British seaside is back – after all, who wants to go abroad with summers like ours…? To celebrate, we challenged some of our finest construction minds (plus sundry offspring) to a giant sandcastle building showdown. Roxane McMeeken and Katie Puckett commentate on the action.

The teams

DJ Green and Associates: David Green and his four sons, Daniel, 9, Jacob, 8, Benjamin, 6 and Nathan, 3

Baqus Kellie Tolmie, Sam Cherrit and Steve Baker

Bennington Green Associates Lynne Hatton,Keith Kirkwood, Daniel Opala and Tom Willis

G&H Mike Crane, Sara Quick and Simon Starks

Building Thom Gibbs, Michael Willoughby and Emily Wright

Assorted architects, surveyors and contractors are standing around on a beach while a man crouched on a 2m-high heap of sand lectures them on how to make mud pies. It’s simple. You just mix sand and water to form patties, and you pile them up slowly to build a tower. “Rub some dry sand around the edges, then give it a little bit of a pat on top to get the air bubbles out,” he says. The demonstration has been going on for some time and the audience is beginning to fidget.

Don’t they realise how lucky they are? Mark Anderson is Britain’s leading sand sculptor, and Building has secured his unique services for the day to preside over our sandcastle building competition. We’ve managed to drag five teams of construction folk away from their desks to take part, all hoping to show off their professional skills by transforming a heap of sand into a fabulous structure. The teams are from QS Baqus, surveyor Bennington Green Associates (BGA), contractor G&H Group, architectural practice DJ Green (“The Greens”) and Building magazine (see the box overleaf for who’s in which).

There was, apparently, only one place to take them: Weymouth. It’s not just its old-time, kiss-me-quick British charm that recommends the place, although there are plenty of holidaymakers enjoying the donkey rides and picture-postcard-perfect beach front. No, it’s the sand.

“I’ve been sandsculpting all over the world for 20 years and whenever I come back to Weymouth, I’m struck by the feel of the sand. It’s like silk,” says Anderson, who has suddenly gone all misty-eyed.

With his demonstration turret taking shape, he changes tack. “You could form a sphere,” he says, deftly creating a sand cricket ball, which is passed round the crowd, who raise appreciative eyebrows.

For a more organic look, the teams could try a “drip castle” – basically a handful of wet sand trickled slowly to form a stalactite.

It looks straightforward enough and the teams are itching to get stuck in. But Anderson is clearly absorbed. Finally he looks up from his turret. “Is everybody happy? Okay then, you’ve got three hours.”

And they’re off…

The Greens: The Greens comprise dad David and his four sons. They did have a plan, but they’ve left it at home. Luckily nine-year-old Daniel, the team’s concept architect, has done a new sketch of a three-tiered structure. Competitive dad David stamps on top of the pile of sand that will one day become it. “Come on boys, we need to do three tiers like Daniel designed it.”

David will, he explains regretfully, have to do quite a lot of bossing of his young team. This is purely for health and safety reasons – he doesn’t want anyone getting hurt.

Baqus: Steve scrambles to the top of a big heap of sand. Down at its base, Sam starts making balls of sand and passing them up to Steve. Steve’s not happy with the first. “It needs to be bigger … and do you call that tight?” It’s already pretty obvious who’s in charge here. Baqus’ design comprises three identical towers, they say. As lumps of sand are amassed, Steve explains to nobody in particular that “it’s not hard physically, it’s more the mental exertion”. Meanwhile, down below him, Sam is sweating as he frantically shovels sand while Kellie drags over a large bucket of water, nearly buckling under the strain …

BGA: Boss Keith Kirkwood is using the competition as an ingenious test of Tom and Daniel’s mettle. He’s holding a picture of London landmark Tower Bridge. “This is what we’re aiming for. It was the hardest thing I could find.” Some challenge given that this is their second day in the industry.

Building: The team spent the train journey from London poring over pictures of the Palace of Versailles, Battersea Power Station, Tate Modern and Hever Castle, but discarded them in favour of Hogwarts. They’re hoping a replica of Harry Potter’s boarding school, turrets and all, will secure them the populist vote. Typical hacks.

Five minutes in, though, and Thom is already backpedalling. “It’s inspired by Hogwarts, rather than an accurate representation …” Meanwhile, team-mate Michael has reverted to a different though equally ambitious brief: Neuschwanstein Castle in Bavaria. “Prince Ludwig built it for Wagner because he was in love with him. We’re mixing high and low culture.”

G&H: The team have already scaled down their project. They had planned on an exact replica of Walmer Castle in Kent, an elaborate 16th-century structure comprising concentric walls, four circular bastions and a drawbridge with a circular keep at its centre. “I think it’s going to be more like a Barbie castle now,” confesses Mike. Which is fitting because the team have brought along a Barbie doll.

Two hours to go…

The Greens: Daniel’s three-tiered structure has morphed into a ziggurat. This is a pragmatic rather that an aesthetic decision: it makes it easier for the shorter members of the team to ascend the pile of sand. While his older brothers are engaged in patting and shaping, three-year-old Nathan is running amok at the base of the structure, wrecking their work with a beatific smile on his face. “Dad, he’s ruining it!” shouts Jacob as another of his levelled steps collapses. David is jumpy, torn between mediating between the warring factions within his project team and listening for his phone. He’s waiting for an important call from a personalised numberplate auction.

Baqus: hurriedly shore up its cracking foundations. After a frenzy of activity it seems that the three-identical-towers design has been revised. “Er, each tower is going to be completely different now,” says Steve.

BGA: Keith whips out a surprise prop: a three-foot long plank of mdf. It’s easier to see how they might achieve some sort of bridge now. But will it be enough to replicate the Victorian grandeur of its subject?

G&H: Walmer Castle is starting to take shape. There’s an external wall with a pile of sand inside it that Simon says is the beginnings of the “inner keep” and the Barbie doll is sitting wonkily on top of it. Simon has brought the Barbie along in a box of other props, some stranger than others. There are cowboys and Indians, a couple of horses, some string, nails and an implement that Simon thinks may be from his fondue set.

One hour to go …

Building: Tension is mounting in the motley crew Building has entrusted with its construction cred. “It’s too wide!” Michael is exclaiming. “I think we should start again.” Actually, the huge mound of sand doesn’t appear to have changed much in 20 minutes. Emily has a brainwave. “It’s beginning to look like something … let’s cut out some mountain passes!” She tries to dig a hole in the side, but she needs water. She dips the tips of her fingers into the bucket of water and looks hopefully around. Building’s impartial reporter indicates the jug – it can’t be cheating when your team looks that incompetent …

G&H: It’s become clear what Simon intended the nails and string for. He’s rigged them up to resemble a drawbridge. The castle’s fully formed, complete with inner keep. Now the team are working on the hill beneath, smoothing it down and carving a pathway snaking down from the drawbridge.

Half an hour to go …

The Greens: This is looking like a classic sandcastle, comprising tiers of sand topped with turrets clearly formed by packing sand into buckets. “It’s taking shape,” says David. “The important thing is keeping the kids busy but out of the way.” While David upturns another bucket of sand onto the pile, Daniel is studiously ignoring his father. He is absorbed in energetically digging a completely unrelated hole.

Baqus: There’s some disagreement among the team about whether the three towers should have been identical after all. “No castle has two towers the same, everyone knows that,” says Kellie. Steve looks at the sandcastle doubtfully; his confidence seems to be wavering. “I don’t think we’re going to win to be honest.” “Well, at least we’re not the worst,” says Sam, looking pointedly at the Building entry.

Building: By now the team has given up. Michael and Thom are sitting on the ground looking dejected, while Emily is playing with one of the Green children.

BGA: The team’s creation is looking not a million miles away from Tower Bridge. The new recruits have even made a car out of Weymouth’s putty-like sand, while Lynne is carving a brick pattern into each tower.

G&H: Simon’s cowboys, Indians and horses are dotted all over the sandcastle, with Barbie taking pride of place in the middle of the central keep like some immense Freudian metaphor. It’s come together impressively – the only prop left over is the fondue fork. Yet Mike confesses that things have not gone as expected. “This is a design-and-build job,” he says. “The result looks nothing like the plan.”

The public vote

Five o’clock and the teams down tools and stand anxiously next to their creations while our reporters quietly poll onlookers for their judgments on each sandcastle.

“The sheer variety is the first thing that strikes you,” says one of them. You can’t argue with that. The Green family’s traditional sandcastle is impressing the voters, “it’s naive, but classic”, says one informed-sounding observer. Then there is Baqus’ “three non-identical towers” design, which is not so much lopsided as “challenging”, a few bystanders decide, diplomatically.

BGA’s Tower Bridge replica seems to be impressing quite a few people, as is G&H’s design, which looks a lot like a real-life castle. Sadly, the Building team’s lump of grey mush doesn’t appear to be catching the attention of many voters. Even Emily’s attempt to cheer it up with a sprinkling of silver stars hasn’t helped.

Finally, the votes are in. A clear winner emerges, and it’s over to Mark to announce that it is … G&H. And it’s no surprise. “This sandcastle has it all: turrets, walls, an inner keep, drawbridge, cowboys, Indians and of course, a Barbie princess,” Mark concludes approvingly. He presents G&H with a bottle of champagne and the adults head off to the pub. Relaxing with our beers, it’s clear there are no hard feelings. Even the Building team is feeling proud of its achievement …

But one team hasn’t made it to the pub – the Greens are still at the beach. Finally, the children have their way and start leaping on the sandcastles, gleefully. In minutes, the results of the day’s labours are reduced back to shapeless piles of sand.

Team Green

This is no mere castle. The Greens have given us a prototype for fortress complexes of the future.

Note the massive permasteel glacis at its base, the row of laser towers above it. And should any assailant make it to the inner keep, they will be met by photon torpedoes, molten lead and live tigers. Alright! This is what sandcastles ought to be like …

Team Baqus

This team’s entry flirts with symbolism, feints in the direction of conceptual art but finally refuses to submit to the reductionist taxonomy of a conventional criticism. Rather, it seems to say, take me for what I am – three unequal lumps of sand on a big hill – and love me anyway

Team building

A typically brilliant display by the Building team, inspired partly by the austere villes perchées of the French Corbières, partly by the deranged Bavarian romanticism of mad Prince Ludwig. Its contradictions are contained if not resolved, by an engineering framework that combines the abstract beauty of pure mathematics with a sad, even tragic acknowledgement that all human endeavour must end in decay and dissolution. [Will that do, guys?]

Team BGA

Here we have Tower Bridge reimagineered as a Greek Orthodox cathedral. The final structure is as remarkable for the severe geometry of Lynne Hatton’s facade, which combines the fin de siècle lyricism of Charles Rennie Mackintosh with the poetic functionalism of Norman Foster, as it is for the bold use of prefabricated mdf to cheat solve the tricky problem of making sand stretch across a large gap

The winners

Team G&H

Okay, so it’s populist. Okay, so it’s historically, geographically and architecturally inaccurate. Okay, so the fact that it’s plastered with G&H flags is a shameless example of product placement. The fact remains that this was the only entry to include cowboys and, relative to the cowboys, a 6m-high woman. This brought together the bleak existential drama of Unforgiven and the arch postmodern irony of Shrek, combining them in an oedipal Freudian narrative. None of the other entries could compete with this for sheer pretentiousness. Oh, and there were towers and stuff that were quite good too …

King of the castles

It took Mark Anderson and three other sculptors seven days to turn 1,000 tonnes of sand into a hotel in Weymouth. It lasted a week and you could sleep in it for £10 a night. Not a bad deal, although it didn’t have a roof … The construction was a stunt to promote website, and its success left Anderson rather bemused. “I couldn’t believe it when I got a call from a Japanese radio station,” he says.

Anderson has been creating amazing things out of sand all his life, splitting his time between sculpting tournaments, bespoke commissions and entertaining the crowds at Weymouth beach. His proudest achievement, he says, was “probably creating the Venus de Milo” – a six foot recreation that took four attempts and three-and-a-half days.

Watch the competition unfold