Self-building is an opportunity to shape your own future. However, when Olaf Mason and Fritha Vincent bought the land to develop their new home they faced a complex puzzle which they solved with expertise, flexibility and sheer determination to achieve their dreams.

The plot for their family home, needed in time to welcome their daughter Lagertha, was consumed by rail and traffic noise and an unforeseen sewer which limited the space the property could be built on.

Dubbed one of the ‘trickiest’ builds ever seen on Channel 4’s Grand Designs, on which the project featured, an exceptional, unique triangular-shaped home was carved with Olaf’s exceptional skills and vision as a carpenter and the use of appropriate products – including ROCKWOOL insulation.


The Challenge

While the shape of the plot and groundwork restrictions largely dictated what was possible within the space, Olaf imagined a unique triangular shaped home that would challenge even the most experienced of architectural designers.

Yet aside from these design challenges that required Olaf to work with complete flexibility and precision – especially when it came to insulation in awkward apexes and tight corners, the plucky self-builders also needed to suppress noise coming from the surrounding A-road and railway.

“I was looking for a sound deadening, easy to fit, eco product that also was non-combustible,” said Olaf, who also built the Triangle House during the height of the Covid-19 pandemic and as he, and his wife, were successful with IVF treatment.

With the race on to complete the project in time, ROCKWOOL FLEXI® slab became an integral piece in this complex 3D geometrical jigsaw.


The Solution

The ROCKWOOL FLEXI slab used on this project is manufactured with the patented flexible edge along one side which supports an accurate fit between the insulation and the supporting framework.

Olaf praised the easy to install insulation which slotted perfectly between his intrinsically designed timber frame construction and the roof structure. Well-placed for new homes, ROCKWOOL FLEXI can be fitted between fresh timber and will expand into the wider space as the timber dries out and shrinks back.

The product, which is suitable for walls, partitions, floors and roofs, is also Euroclass A1 non-combustible and provides additional thermal and acoustic benefits, making it the ideal choice for this unique Sussex property in its busy urban setting.

ROCKWOOL FLEXI also supported Olaf and Fritha’s environmental aims for the Triangle House as the product’s versatility helps to minimise on-site waste. FLEXI, like all ROCKWOOL stone wool insulation, is made from renewable and naturally occurring volcanic rock.


The Result

Paul Barrett, Head of Product Management at ROCKWOOL said: “The Triangle House is a shining example of what’s possible with architectural vision, determination and hardworking technical solutions. Combined with Olaf’s incredible vision and master craftsmanship, plus a multi-use, dual purpose product, like our acoustic, thermal stone wool FLEXI slab insulation, shows how dream homes of all shapes and sizes can become a reality, no matter what the challenge is.”

Olaf concludes: “It was always an aspiration of mine to build our family home and despite many of the hurdles we faced, we tackled them head on.

“I strived to make the house as eco-friendly as possible with the use of sustainable products, and through the use of ROCKWOOL insulation, it helped me achieve those goals, as well as it being easy to cut, time-saving to install, noise suppressing and adaptable to the requirements of the house.”

I was looking for a sound deadening, easy to fit, eco product that also was non-combustible.

Olaf Mason

Self-builder and owner of The Triangle House
Triangle House
Triangle House
Triangle House
Triangle House
Triangle House

More ROCKWOOL Case Studies...