As more of us start to feel the financial pinch, never has the idea of renting out a cluttered and rarely used spare bedroom seemed so attractive. You can earn up to £4,250 tax-free under the Government’s rent-a-room scheme which works out at around £350 a month – an amount that could make all the difference if finances are a bit tight.

Obviously, the better the room, the more you can charge for it. While it is getting increasingly hard to sell properties, the rental market is booming. If you’re a homeowner who isn’t going anywhere for the foreseeable future, now’s the perfect time to bide your time and make some extra money.

However, more choice for the renters means they can afford to be picky. Therefore, it’s worth investing a little capital to create a room that will be attractive to potential lodgers.

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Judy Niner set up Mondaytofriday. com, after realising that many professionals want a base near their work during the week before returning home to their families at the weekend. Her advice to potential landlords? “First of all, the bed has to be really comfortable. You won’t attract, or hang on to, lodgers if they aren’t getting a decent night’s sleep, so invest in a decent mattress,” she says.

“If you need to make more than £400 a month in London, your lodger will need to have sole use of a bathroom. It’s possible to buy small en suites and if this is going to be a long-term option, it’s worth thinking about creating another bathroom for either the lodger or your family.

“Finally, since both students and professionals will probably want to use a computer in their room, Wi-Fi access is a must. If you aren’t prepared to share your sitting room with your lodgers in the evenings, access to a television is also important.”

To maximise space, consider installing a double sofabed, or a bed that is built into the wall. The London Wallbed Company (020-8896 3306) has a good selection of beds which double up as sofas and even desks when not in use. However, its desk/bed costs over £2,000. A cheaper alternative is its CuBed, which folds up almost flat against the wall and the underside can be painted to match the wall, or in blackboard paint to double as a noticeboard. Prices start at £840.

As Niner points out, the other basic requirement is a television. A wall-mounted flat-screen TV won’t take up valuable floor space and if you have a Sky box you can upgrade to “multiroom”, which allows the tenant to watch what they want in their room for an extra £20 a month with a one-off payment of £49 for a second Sky box. Otherwise, be prepared to open up your sitting room in the evenings for communal viewing.

Next up is the bathroom. It doesn’t have to be en suite but it should be for the sole use of the tenant. If installing a private shower is too pricey, draw up a written agreement with the lodger about when the family bathroom can be used. Ideal Standard (01482 346 461; www.ideal-standard.co.uk) has a triangular shower room. At 1.6m x 1.6m, it will fit into most master bedrooms, so you can free up the family bathroom or build it into the lodger’s room. It costs from £1,900, excluding installation and tiles, but, with a shower, basin and loo that are all designed to fit across the corners, it is probably money well spent.

The other area of contention is the kitchen. Niner says that once again you have to decide how much of your house you are willing to share.

“I enjoyed being able to talk to the family and live with them as a paying guest and sit with them in the evenings to watch television,” she says. “But if it’s a long-term let and you want the lodger to be more independent, then provide the basics of a kettle and toaster.” Buying a mini-fridge will also allow a tenant to breakfast in private. Alternatively, invest in a tiny kitchen – or even just a microwave.

Richard Rogan, of Spacesavers (020-7624 1002; www.spacesavers. co.uk) says: “The rental market is very competitive and tenants have quite high standards. For around £400 you can choose a range of small appliances or, for a little over £2,000, you can buy a kitchen in a cupboard (it needs to be about 1m deep). This will include a mini dishwasher, microwave and fridge. It takes about a day to install and that price should include any extra plumbing and wiring necessary."

Finally, keep the décor neutral and the surfaces free of clutter. A full-time lodger might want to hang pictures on the wall and even shelves. Someone who goes home at weekends is probably looking for more of a comfortable hotel feel and will expect bedding and towels to be provided.

After you have created the room of a lodger’s dreams, where do you find a sympathetic, responsible character who won’t trash it? In addition to Mondaytofriday.com, which will try to net you a professional who goes away at the weekend, there are plenty of other sites which will find you a tenant (see box). If you have a full-time lodger, you can charge 40 per cent more than for a part-time resident. Once you have found someone, visit www.tenantverify.co.uk to check their credit references, and call your home insurance company to check that you, and the tenant, are covered. Finally, draw up a written agreement about things such as when and how loud music can be played.

When the lodgers have gone, you will be left with a fabulous guest room, and a second bathroom which has not only paid for itself but which will have added value to your property as well.

Useful information

* To offer or find a room, try www.mondaytofriday.com, www.spareroom.co.uk and www.roombuddies.com.

* Consider putting a notice up in a local college or university.