For the latest trend in home improvement, don't look up – look down!

Loft conversions are old news, and what most homeowners don't realise is that their dusty cellar or smelly basement is actually an extra room worth thousands of pounds, as well as one which can dramatically enhance you and your family's lifestyle.

This cost-effective craze has been big news in London for a while, where cramped homeowners are keen to use every square foot of space, but the trend is now taking off in other parts of the UK such as Manchester, Leeds and parts of Scotland.

The main reason basement conversions are really growing in popularity is because, unlike loft conversions, basements are normally closer to other communal areas and can be more versatile living spaces that suit modern lifestyles, not just extra bedrooms, bathrooms or studies.

Let your imagination roam free

Perhaps the most exciting reason to 'extend' underground is that you can really enhance your family's lifestyle.

Your kids can have a giant playroom all to themselves – or the bigger kids can treat themselves to a home cinema, a recording studio, or a state-of-the-art wine cellar to really indulge their passion.

If you own a commercial property it's also worth remembering your basement could earn you thousands as extra storage, retail space, a car park or even a bar or nightclub.

Are there any financial benefits?

Apart from the extra space for you or your family, a basement conversion can earn you a packet in additional rental income.

Most simply, you could rent the converted basement to a lodger, who would then share the kitchen and bathroom with the family.

Or, alternatively, you could convert the basement into a self-contained studio apartment, with its own front door if so desired. If that sounds appealing, however, you should be aware that you will need planning permission if you plan to create a separate entrance to your home.

But even if you decide not to rent out your converted basement, a simple conversion can also add on thousands to the value of your property when selling it on.

Doing your bit for society!

It might seem far-fetched but basement conversions were championed by the Minister of State for Housing and Planning in 2005 as a way of addressing the UK's increasing inner-city dwelling density. So you'd also be helping out the Government!

Is my basement suitable for a conversion?

Luckily, Victorian houses, and older types of properties which have timber-suspended floors, are ideal for cellar conversions, as the work can often be carried out from outside, which means you can easily continue to live in your property while the renovations are taking place.

A word of warning, however, some older houses may have shallow foundations, so in order to create a safe living space below, you may need to underpin your property first.

If this is the case for your property, then the easiest thing to do is to talk to an underpinning firm or specialist builder who can advise you on feasibility and cost of the job.

Remember – while a basement conversion may seem like a dream come true, always make sure that a cellar conversion is a realistic venture for your property before forking out any cash.