Creating space in your home

There is surely no better way to kick off this new decade than with an architectural showpiece demonstrating clever and inspirational home extensions - "green" too - that do not cost a fortune.

New London Architecture, based at the Building Centre off Tottenham Court Road, is a forum for the capital's best design, with a year-round programme of events and exhibitions. Its latest offering highlights 32 London domestic projects, ranging from basement excavations and fabulous glass extensions to rooftop additions and mezzanines.

Don't move - improve. That was the popular trend towards the end of the Noughties as the choice of properties to move to dried up along with the availability of mortgage money. Increased moving costs and the loss of jobs further encouraged people to stay put.

It is a "nesting instinct" that persists in this new year, according to a new report by insurance company Aviva that suggests 75 per cent of home owners plan to stay in their property for the long term.

Creating extra space is the home improvement that adds most value to your property and can be transforming in the lifestyle benefits it brings - but only if projects are well conceived and well executed, says Hugo Tugman of design consultancy Architect Your Home.

"Adding value is much more about quality than quantity," he says. "But you can achieve impressive results on a relatively modest budget."

"Normally, the cheapest way to add space is to convert the loft, followed by a rear extension. Going underground tends to be more expensive because excavation costs are high."

Recent relaxation of planning laws means many more owners have "permitted development rights" allowing them to extend without the consent of the local council.

We built under our lawn

With two toddlers, Nigel and Chantal Dyble needed more space than their 1,300sq ft garden maisonette in Camden provided. "Moving seemed too much of an upheaval - my wife was pregnant at the time - and it was going to be expensive, too," says Nigel, a City banker. So the couple, both in their forties, came up with the idea of selfcontained accommodation in the garden — a multi-purpose "hidden house" below their lawn, suitable for an au pair or for use as an office or guest suite, even for short lets to generate extra income.

Their home is part of a substantial Victorian building (the size of four town houses) split into apartments. The garden measures approximately 70ft by 25ft and has separate side access.

Working with architect Jake Edgley (www.edgleydesign.co.uk), the design priority was to bring natural light and air into the underground space. This was achieved by dropping a frameless glass cube into a concrete shell and incorporating a timber-clad internal courtyard, which doubles as a lightwell.

The 500sq ft space can sleep four and has a bespoke kitchen along one wall plus sliding partitions and foldaway furniture for extra flexibility. Intimate, quiet and peaceful, the bijou dwelling is a discreet sanctuary amid the bustling streets of north-west London.

"The light is so good you don't feel underground, and it is absolutely silent," adds Nigel.

The garden was reinstated and given new fencing and decking which made it look better than before. The entire project (including planning permission) took 18 months. Neighbours were broadly supportive. However, the Dybles ended up about £40,000 over budget because of excavation complications. The final cost was close to £250,000.

"Today, the combined property is worth about £1.3 million, which doesn't totally reflect the investment we have put in, but we believe we'll reap financial rewards in the future when the market fully recovers. Already the space has made a huge difference to our quality of life.

"We have friends and family staying there, and have rented it out - several times to a Japanese chef, who adores it. We reckon we can make about £15,000 letting it out for six months a year."

Permitted development: what you need to know

In simple terms, there are now alterations that you can make to your house - including certain extensions - without obtaining planning permission.

You should confirm that yours is a permitted development before undertaking any work, but in general, you should not require planning permission if you are planning:

* A side extension that is less than half the width of the original dwelling.
* A single-storey rear extension up to three metres in depth (but four metres if it is a detached property).
* A loft conversion, including a rear dormer.


For more information about permitted development, visit government website www.planningportal.gov.uk, which has a useful interactive guide covering all types of residential property.

All schemes are on display at New London Architecture, 26 Store Street, WC1E 7BT. Visit www.newlondonarchitecture.org.

Another useful source of free information is Planning Aid for London (www.planningaidforlondon.org.uk, or call them on 020 7247 4900).