A perfect way to rack up the wow factor in a home is to use lots of glass. It doesn't come cheap, and glass added to exterior walls and roofs can be difficult to get past the planning department, but if you solve the hurdles you can transform a dark and dingy home – and substantially raise its value into the bargain.
Housebuilders, developers and architects are increasingly using glass: skylights, atriums, conservatories in internal rooms, interior glass walls, massive exterior walls, floor-to-ceiling windows, glazed balconies, staircases and walkways are all increasingly being incorporated into new developments or added to existing ones. Today's generation of glass is tougher, more sustainable and has greater thermal qualities, and therefore can be used in ways previous generations could only dream of.
"Glass is a magic material. It's solid, yet you can see through it," says architect Francesco Draisci, who has opened up homes with huge glass doors and walls that when folded back allow the lower floor to continue right into the garden.
"More and more buildings are using large extents of glass," he says. "Loads of people are wanting to open up to their garden areas, it is the opposite of Victorian times when there was much greater emphasis on the street facing side of buildings, and the garden side was neglected.
"Technologically, the possibilities have been widening in the last century, and in the last 20 years double and triple glazing advancements mean less and less loss of heat. The advent of self-cleaning glass means there is less maintenance too."
Perhaps we are only beginning to open up our homes because we've been shackled by our British reserve: in many parts of the continent homes are far more open to public view. Visitors to cities like Amsterdam and Antwerp, for example, are often struck by how easy to peer into peoples' homes from the street, there's not a net curtain or blind to be seen along whole rows of houses.
Banker Jack Jones, 41, and his wife, teaching assistant Diana, 45, made huge structural changes to their home to enable installing nine-metre-long folding glass doors. They, and daughters Lucy, 12, and Kate, 10, can now make the walls separating the open plan kitchen/living area at their home, an Edwardian four-bedroom detached house at Pinner in Middlesex, from the outside terrace instantly vanish.
"The whole intention was to bring the outside in," says Jones. "The front of the house is traditional 1920s, but at the back we've taken out all the internal walls to make the floor open plan, and with the glass doors we can extend the garden into the living area.
"We've modernised the house for flexible, contemporary living. The glass is in the family area, the centrepiece of the house, we spend all our time there. It brings in so much light and there are blinds set in the doors for if we want privacy."
Jonathan Bordell, property consultant, uses lots of glass in his developments: "Whenever we try and sell a property it has to have something that stands out, and the easiest way to do that is to introduce natural light. We recently used a lot of glass at a £3.5m property in Chiswick, London. One of the outside wall's panes of glass was nearly two tonnes in weight alone – there's six tonnes of glass in there.
"Introducing glass brings problems to solve and is a very expensive process, far more than using usual materials, but in my view well worth it. You can't just install any glass, you need it to have passed specific UV absorption tests, it needs to be energy efficient, and also satisfy a wind deflection test so that it doesn't shatter when there's a strong gust of wind."
But is it appropriate to slap ultra-modern features like huge expanses of glass on to traditional architecture, such as from the Victorian and Edwardian eras?
"Yes, it works. I think people are looking to meld old and new, and nowadays planners don't want to see pastiche designs mimicking what's already there. They can prefer a mixture of old and modern."
Bordell is currently working on a development of £299,995 contemporary two-bedroom apartments created from a four-storey Victorian villa in Ealing, London. To increase light, he opened up the roof and loft area with new glazing, flooding the building with light. People worry about cleaning glazed roofs like this, but Bordell incorporates reversible inspection hatches at his developments so that cleaning does not present a difficulty.
"Lots of glass is certainly a preference from an architects' and residents' view," says Rupert Dawes, partner at Knight Frank residential development. "But the barrier to that is the regulations. Everyone wants to use glass on bigger developments but can't do with current regulations."
Regulations governing thermal performance are often the biggest problem to overcome. Use of glass is generally limited to around a quarter of the floor area of an extension, although improving thermal performance elsewhere can strengthen your case.
"On residential homes we are seeing more extensions using lots of glass," says Dawes. "If two properties are for sale side by side and one has lots of glass, making it look lighter and bigger, it will always sell over the other."
NEO Bankside, a development comprising 197 £650,000 to £8m one to three bedroom apartments and penthouses set among landscaped gardens in London's Bankside and being marketed by Knight Frank, using lots of glass, with features like glass lifts. Apartments feature floor to ceiling glazing to a height of 2.6 metres and glass-surrounded winter gardens.
At Dymock House in Fulham, London, a £1.525m spacius three-bedroom detached house with much open-plan design, developers Stephen Brew and David Hubbard of Plan Build Live have installed features like a glass walkway and atrium and a glass and walnut staircase.
"There's a definite trend to use more glass," says Stephen. "Planning restrictions were easier to overcome than usual because Dymock House was previously a warehouse and it was easier to add glass when the building was granted a change of use.
"Glass and technology have moved on so much that you can now have complete glass extensions made with frameless glass. That's really popular now, even though it costs a lot more than traditional materials like brick. With these glass boxes you can still see the existing building through them, meaning it is easier to get planning permission. You lose privacy, but then there is always a trade off of some kind.
"Another development is SmartGlass, where a flick of a switch puts an electric current through the glass so that it becomes opaque and can provide privacy or keep out sun. It's very expensive, though, costing about £1,000 per metre, but the effect is amazing."