How much is … making a home secure?

The first step to making a home secure is to look at the downstairs doors.

It is estimated that burglars enter more than two thirds of properties from the rear, so securing back doors is vital. Every external door should have a lock operated by a key: a British Standard mortice deadlock is best.

But although burglars come in through the back door, they want to leave by the front. "If you walk out of a front door with a TV, nobody will look twice – they'll think it's being repaired," says Richard Marson, chief executive of the BEESAFE Project, a charitable security company that recently worked on the homes of about 100 vulnerable people in Brent, north-west London. This is a good reason to have a front door that can't be opened from inside without a key.

If the door frame is weak, you can attach metal strips to it. These are called London bars or Birmingham bars and strengthen the lock or hinge sides respectively. And if the door opens outwards, you will need a hinge bolt to stop someone lifting the pin out of the bolt and removing the door.

Doors are also important for stopping unwanted visitors. A chain buys extra time after the door is opened to get to the phone if there is a problem. BEESAFE often fits mirrors on the wall next to the chain, so the tenant can see the caller while still standing behind the door.

After the doors, you must secure the downstairs windows. "If a window opens wide enough for a head to fit through, it needs a lock," Marson says. Key-operated window locks should be fastened to the top and bottom of the window frame.

Patio doors are another vulnerable point. Older designs can be lifted up and removed, so need anti-lifting bars at the top. These can be expensive, but a wooden baton will do just as well, according to Marson.

If there is a porch, extension or pipes that aid access to upper windows, you could use anti-climb paint. This can be used sparingly – just a lick halfway up will do the trick.

Back garden fences should be at least 6 ft high and Marson recommends putting a trellis on top. "People say: 'That won't keep anybody out because it's so flimsy', but that's the idea. It won't take anybody's weight so when they climb on it, it will break." The gate should always be locked and bolted top and bottom. Prickly bushes around the boundary can also help.

The extras
There are many other things you can do for vulnerable tenants. The elderly can have a "key safe" outside the property, a box that holds the keys and is accessed by a digital code that neighbours and care workers can use. You can also get adaptors for night latch locks (Yale-type locks) that make them easier to turn and even arson-proof letterboxes, which are made of metal and have a fire extinguisher inside them that goes off if the temperature gets too high.

For front doors, there are spy holes with built-in intercoms that allow the tenant to talk to callers before opening the door.

And what about strips covered in sharp plastic to put on your garden walls? Or metal security gates outside the front door?

The greater the fortification, the greater the cost, but Marson says even basic changes make a big difference. "I knew of one guy who had 498 offences for burglary and all he did was slip the front lock with a credit card," he says. "He could do it in less than 10 seconds. He looked at houses to see what sort of locks they had and didn't go up to the ones with mortice locks."

With mortice locks costing as little as £20, it's a small price to pay.