Ask the expert
Architect Mark Watson tells Amelia Thorpe about the limitless possibilities of glass
When is glass the best solution for adding to the footprint of a building?
To punch light into the heart of a building, glass is ideal. Any extension will increase space, of course, but a glass one can transform the darkest interior and bring a house alive. Glass can also be used to create an almost seamless connection with the garden.
What is the best way to integrate a glass addition into an existing building?
I like to take details of the house and reimagine it in a modern way. The conservatory at the listed regency villa, Sandridge Park (right), has contemporary sliding glass screens within an external structure supported by fluted cast-iron columns, as a reworking of an original verandah. From the inside, the glass creates the modern impact; from the outside, the structure respects the original building. The roof of the conservatory is extended at one end to create an alfresco eating area, with the cast-iron columns running all the way around to continue the rhythm of the design.
What does glass bring to an interior?
By introducing natural light, glass can have major impact on every interior, but the best glazing solution will depend on the style of building. For example, conservation roof lights are generally the only permissible way of getting light into a roof void in a listed building.
A roof lantern works well on a flat roof extension, because it allows light to flow into the heart of the room. However, beware the ‘black hole’ at night: lights around the inside perimeter of the lantern opening will address this and allow the lantern itself to become the light source.
Barn conversions are notoriously dark, because few windows are generally permitted by planners, so it’s important to make the most of the barn-door openings with maximum glazing.
A conservatory or orangery can make an excellent extension to your kitchen or living space and my preference is for fully glazed walls and doors. Sliding folding doors and subtle means of ventilation make it easy to control the environment, are easier to maintain than glass roofs and glass screens can offer a wonderful sense of ‘wow’.
Crittall-style windows and French doors can work beautifully by a small courtyard garden, because they contain the space, in contrast to the sense of seamless flow created by a minimalist glazed panel opening up on to a large vista.
In both scenarios, however, it’s worth lighting plants, a sculpture or interesting exterior feature to draw the eye and avoid creating the ‘black hole’ effect from the interior at night.
The Sandridge Park conservatory may be contemporary in style, but it respects the design of the original listed builiding