Doors have many obvious functions in the home but keeping occupants safe and secure is one of the top priorities.
To achieve that, many homeowners and commercial office tenants will have burglar alarms and other security devices installed to protect against intruders and other criminals.
But the first step in protecting your home or office against a break-in is to make sure that entry points are robustly controlled.
And that means installing doors and windows made of sturdy material and securing them with good locks and hinges.
A door that is not well built or adequately installed will be an attractive target for any potential intruder or opportunistic burglar.
In combination with an effective security alarm system, robust, solid doors and windows on your property will prove a severe deterrent to any would-be burglar.
Cost is always an issue when replacing doors and windows in your home or other property, and it is tempting to opt for the cheapest.
It can be a false economy though, as cheaper doors are often constructed of flimsy materials, which means they last a shorter time and fail to provide a reasonable level of security.
A cheap door can easily be prised open or even kicked open by a determined intruder. Acceptable perhaps for internal doors where security is not such an issue, but highly inadvisable for external doors.
All doors that allow access to a property should be made of robust, solid materials, have substantial hinges and good quality lock mechanisms.
When fitting a new or replacement door, the strength of the actual frame may be overlooked. Yet even the strongest door is only as secure as the frame it is fixed to.
An intruder with a crowbar can easily prise a flimsy frame from the wall and quickly gain entry without even bothering with the lock.
The strike plate that holds the door bolt in the frame is another potential target for an intruder.
The plate needs to be thick and strong and fixed firmly with deep screws to ensure it can't be prised off the frame.
Another potential weak point is the lock casing, which can be levered out of the frame if loose or insecure.
There are many types of door locks on the market, and there is little point in spending more money on a good, reliable door if the lock is not up to the job.
Door locks are graded one to three for security, with grade one offering the highest level and grade three the lowest.
A secure door lock will have a deadbolt with a minimum one inch long-throw bolt. For the highest level of security, consider a second vertical deadbolt that can't be prised open easily.
Remember that even the most robust door will fail if the bolt does not extend far into the frame, the strike plate is not firmly fitted, or the frame is ill-fitting or flimsy.
A door may be well made of thick and sturdy material, but if the hinges are weak or screws are exposed, it becomes a simple matter to break in.
A potential burglar can easily unscrew exposed hinges or prise them off with a chisel if they are poorly fitted to the door frame.
The door must be hung on at least three strong hinges that are inaccessible once the door is closed. If not, the door will present little difficulty to the experienced burglar.
Electronic door entry access systems are becoming more popular these days, especially for commercial properties.
Keys can not only be lost; they can be easily copied. You can even take a photo of a key on your mobile phone to order a replacement. Convenient for you but helpful to a burglar who no longer needs to steal a key to get a copy.
Lost keys are, of course, a major security risk and can mean getting locks changed on all the doors, especially with commercial premises where several people may hold keys.
Electronic door access systems allow access codes to be changed at any time and for lost fobs to be deactivated.