When a client appreciates the quality of the work they are getting it makes producing the best quality work so much more enjoyable for the craftsman. The result can be a project that is a notch or two above the ordinary, as demonstrated in the new Blaxter sandstone orangery at the Old Vicarage in Barnard Castle, Co Durham. The stonework was the province of Liam Glasper and Ashley Tunstall, who trade as Glasper Tunstall Stonemasonry in Barnard Castle. It is an indication of how much the client, Paula Scott, cared about the project that she was prepared to pay an extra £6,000 to have the stone hand tooled to match the existing house. And it is an indication of how much the masons knew she cared that they suggested doing it.

The Old Vicarage at Barnard Castle is not fussy or overly ornate but quietly distinctive. Built in 1855 it is now listed Grade II, but even if it had not been the current occupants would have wanted their new extension, an orangery that joins an outbuilding used as a gym to the house, to be in keeping with the rest of the property. And they have gone to some lengths to ensure that it is.

And now it is finished Paula Scott is delighted with the extension to her house, especially the stonework by Liam Glasper and Ashley Tunstall. “The quality of the workmanship is incredible,” she told NSS. “It surpassed all my expectations, to be honest.”

The easy answer would have been a timber frame on top of a stone wall, but Paula says she knew what she wanted and that wasn’t it. A stone structure was going to be more expensive but, she says, “I would rather spend my money on this place than designer handbags”.

The best match for the original stone of the Old Vicarage was Blaxter sandstone from Dunhouse Quarries, based in Darlington, which has been used for the walls and the steps. Another Dunhouse stone, Catcastle buff, has been used for the paving and Crema Marfil forms the floor inside. The stone for the walls was supplied by Paul Allison’s Dunhouse Quarries while his sister Sue’s business, Purple Tree, supplied the paving and flooring.

The design for the extension came from Colling Morris of Planarch Design in Bishop Auckland. He says he pulled the existing features of the building into the new extension, even though it was a steel framed building complying with modern building regulations topped with a lantern light. He told NSS: “Mrs Scott had given us quite a comprehensive brief about what she wanted.”

A key feature to be transferred to the new extension was the thickness of the walls, which has resulted in some hefty stonework – and it all had to be manhandled into position because it was not possible to bring machinery on to the site. Some of the mullions are 250mm thick and weigh 660kg. They were lifted into position using block and tackle attached to an ‘I’ frame on the scaffold.

Transferring elements from an existing building to a new section always leaves a designer open to the accusation of pastiche, but Colling says: “In this instance it was the right thing to do, I think.” And he is delighted with the skill with which the stonemasons have done it. “They have carried out the construction of the orangery in an absolutely exemplary way.”

Not that it came as a surprise to him that they should produce exemplary work because it was he who put their names forward when Mrs Scott asked if he could recommend anyone. He had worked with Liam and Ashley previously and knew the extent of their skills.

The two masons served their apprenticeships together at Dunhouse Quarries 19 years ago, during which they attended the stonemasonry courses at York College. They continued working together when they branched out on their own 12 years ago and seven years ago formed themselves into the limited company of Glasper Tunstall Stonemasonry, working from a small light industrial area of converted farm buildings in Barnard Castle.

They do a lot of repair, restoration and extension work but, says Liam: “This is the finest job we have done.” Ashley adds: “It’s a very rare opportunity to put something of this quality on a private house.”

They say that not being able to bring machinery on site made handling the Blaxter stone harder than it would otherwise have been, especially as some of it was so heavy. “We were always watching our arrises,” says Liam.

The masons were working alongside builders Mike Neesham & Son from Bishop Auckland, who put in the foundations, erected the steel frame and put in the woodwork and lantern roof.

Glasper Tunstall worked closely with Dunhouse quarries and praise the accuracy of the Dunhouse sawmen. “They did a fantastic job,” says Liam.

Planarch produced drawings of every section, from which the masons made templates.

Paula Scott was particularly pleased, if also surprised, at the speed at which the masons worked. She says a previous project on her house had left her dreading a protracted building programme to complete the orangery. But it was done and dusted in 17 weeks, even though work was halted for three of those weeks by the snow.

The masons are more critical. They were supposed to have been on site earlier in the year, which would have meant they were finished before it started to snow, but were held up waiting for the 2m deep foundations.

Before the snow came rain, which saturated some of the lime mortar before the cornices were installed and left some repair work to be carried out on the mortar at the top of the walls.

But in spite of what were fairly minor difficulties along the way, Liam and Ashley were delighted to have had such an interesting project to work on.

Now they are building a 200m² bungalow, most of which is random rubble walling. But they have already been commissioned to carry out more work at the Old Vicarage and the orangery there has led to another similar project for them. Ashley says: “I was talking to someone about another job and mentioned the orangery at the Old Vicarage. They came and had a look and now they’re having one as well. Planarch Design have been there to produce the drawings.”

In the meantime, Glasper and Tunstall Stonemasonry have entered the Old Vicarage orangery into the Durham County Council Environmental Award Scheme under the craftsmanship category. If they win it, it will be their second, because they have already won one Craftsmanship Award in the scheme for a new door frame they put in at the Georgian mansion of Thorpe Hall at Wycliffe.