Let the light in: Garden rooms

A garden room could be the missing link between your home and the great outdoors

Words Rosie Duncan


Kalm Architecture added a modern extension to an 18th-century home
Kalm Architecture added a modern extension to an 18th-century home

“The design was specific to the scale of the existing house, an attempt to build a contemporary timber garden structure but with a wall depth and scale that complemented the Georgian thick walls and high ceilings,” explains Kalm Architecture’s Kevin Adams, of his extension in York Road in Edin­burgh’s Trinity area.
The structure, completed last summer, was called for by the family to make the most of a considerable stretch of garden and to use as a living and dining space. It replaced a bay window which wasn’t an original feature of the house. Of its two principal elevations, the east façade mimics the geometry of the house, while the diagonal south-east façade offers large glazed doors, built to soak up the sun.
And making the most of the plot’s assets doesn’t stop there: a new doorway from a ground-floor guest bedroom leads to an outhouse on the north side now transformed into an en-suite. The biggest challenge? The house’s solid masonry, which was lightened with timber.

Kalm Architecture, 01620 850649


Extension: Timber-and-steel hybrid structure
Build time: Six months
Dimensions: approximately 22 square metres
Overall cost: £85,000, of which £65,000 was allocated for the garden room
The brief: Creation of a space that provided a dialogue between the outdoor and indoor areas
Contractor: Braidwood Building Contractors Ltd; Quantity Surveyor: Ian Hogg;
Structural Engineer: Gordon Eadie


Trombé Architecture used extensive glazing to update a red-brick property
Trombé Architecture used extensive glazing to update a red-brick property

Glass is a key component in any garden room, allowing daylight to linger and the property’s exterior to shine. But how best to achieve the floor-to-ceiling panes of Trombé’s extension? “We were asked to create a large and bright sunny room that brought the outside in,” explains the firm’s Stephanie Hill. “The client wanted a space that flowed into the garden and back into the house. The existing external steps from the first floor to the garden had to be replaced and this was done by using a walk-on glass roof, creating a terrace with new glass balustrade and timber stairs down to the garden. The whole space is usable, including the roof.”
For glass that serves a purpose other than offering an uninterrupted view of the garden, Hill advises a tougher approach and careful consideration of the building’s orientation. Solar control glazing is a good option for structures in direct sunlight and low-iron glass will reduce a green hue. For similar walkways, Trombé found laminating the material strengthened it, and included an inner sheet of K glass for the double-glazed units used for the roof, doors and walls.
Be warned: this kind of exposed structure is best in a private garden, as envious neighbours won’t be able to take their eyes off it.

Trombé, 020 7688 6670


What: A structurally glazed, steel-frame extension
Build time: was four months
Dimensions: approximately 8.8 by 3.2 metres
Cost: £80,000, excluding building work
For a garden room of this kind, attention must be paid to ventilation and heating. Trombé suggests underfloor heating for the cooler seasons and air conditioning or a purge ventilation system for the summer months


Mozolowski & Murray’s structure slots into the corner of the property and works with its original architecture
Mozolowski & Murray’s structure slots into the corner of the property and works with its original architecture

A traditional conservatory was the starting point for this garden room to match the style of the house. Mozolowski & Murray worked with structural engineers Fairhurst of Aberdeen to overcome the site’s primary difficulty – its being in a conservation area – by mirroring the property’s interior and exterior character. “There are some lovely features internally that we wanted to emphasise,” says the conservatory’s designer, Virginia Murray. “The stone walling was retained and we incorporated soffit lighting in our design to shine down onto the stone.
“We also designed the gable roof on the side elevation to reflect the roof, allowing us to project the side elevation out slightly to add interest to the space internally. The ‘hipped’ roof on the front elevation also reflects the hipped roofs on the property.”
The final structure makes as little impact on the property as possible, while also delivering on some modern, practical solutions. New drainage connects into the existing system, for example, while cutting-edge new-generation Low E glazing gives heat retention and thermal efficiency.
If you’d like something similar, Murray’s advice is not to let the garden room overshadow your current space: “If you’re going to use an area that you currently enjoy, such as a patio, consider how this would either be relocated or incorporated into the new conservatory design, with doors leading out on to it. Think too about which part of the house the conservatory will lead from and how it will be affected. You don’t want to lose a room to gain one.”

Mozolowski & Murray, 0845 050 5440


What: A bespoke design with ‘hipped’ and gable roof shapes, with astragals to window sections
Build time: Four weeks
Dimensions: approximately 20 square metres
Budget: Around £45,000 for a similar project
The structure is glazing with Low E glass that has an argon filling, which “has a micro­scopically thin and transparent metallic coating, reflecting longwave heat radiation back into the room,” says Murray. The brief was built around maximising the corner site and views across the garden