Derek James discovers how Lusher and Son Ltd transformed Norwich Cathedral into a giant's castle for a new Hollywood blockbuster.

Transforming Norwich Cathedral into a fairytale castle has to be the strangest job Lusher and Son Ltd has ever won – despite a history spanning four generations and two centuries of working on historic buildings around Norfolk.

Craftsmen from the Sprowston-based family firm this month transformed the soaring gothic interior of the cathedral into a giant's castle for a Warner Brothers film starring Ewan McGregor.

Managing director Mark Lusher said the company had done a lot of work at Norwich Cathedral, but nothing like this.

Most of their work is designed to last decades, if not centuries, but the temporary transformation from cathedral to castle lasted just weeks, while Warner Brothers filmed part of their latest blockbuster. The Lusher craftsmen then helped return the cathedral to its previous glory.

Mark is the third generation of Lushers to run the company, founded by his grandfather, the wonderfully named William Slaymaker Lusher, in 1924. His father, William Ivan Lusher, became an apprentice in 1942 and ran the firm until Mark, now 56, took over.

Both his daughters have helped out too, although neither works for the company right now.

And it is not just the Lusher family which makes it a family firm. Many of its staff are fathers and sons too. Lusher and Son has taken on apprentices throughout its history and still offers two training places a year. The name of each new apprentice is still carefully hand-written in a leather-bound ledger. The early pages of the book are lost but every apprentice taken on since 1951 is included – and many of them still work for the company. A recently retired estimator worked for the company for 60 years and several staff have been with Lusher for 50-plus years.

'I love the way we are a family business,' said Mark. 'Our men are the patient type. It's work which needs a lot of care, and craftsmanship is the byword.' The company still takes on apprentices as young as 16 and Mark said revived respect for heritage crafts meant he was seeing some very good candidates.

The founding William Lusher was a carpenter. His son was originally an apprentice bricklayer with the company and Mark trained at what was then Brixton Building College and is now part of London's South Bank University.

Right from the start the company began building a reputation as specialists in repairing historic buildings, although they also have divisions looking after modern extensions and alterations, and minor works and maintenance too.

Machinery in the joinery shop, bought second-hand by William Slaymaker Lusher, is still in use today (many, many health and safety adaptations later.)

Today the men of Lusher and Son Ltd have worked on more than 350 of Norfolk's medieval churches, plus everything from stately home renovations to sea-plane runways.

They have built four crematoria, including St Faith's, and their work at Norwich Cathedral has spanned renovating the spire, when Mark's dad was in charge, to working on the new hostry in the 21st century – and the big screen call-up this month.

In 1978 they were granted the Royal Warrant for their work at Sandringham and every autumn they carry out a planned maintenance programme for the royal home – before the Queen arrives for Christmas.

And the traditional skills demonstrated by the team in the 21st century would have been familiar to Mark's grandfather in the 1920s.

Some would even have been recognised by the craftsmen who originally built the churches and historic houses which Lusher and Son Ltd looks after today.