THEY say never judge a book by its cover, so why judge a house by its front door, asks Luke Rix-Standing.

WHEN it comes to our homes, first impressions count: Your front door is the first and last thing seen by visitors, and there’s a lot to be said for kerb appeal when it comes to buying and selling.

If you're looking to give your front door an upgrade, here are four things to consider.

- Material matters

Doors have traditionally been fashioned from wood, but modern models have expanded into composite materials and cheaper, more durable substitutes like uPVC. So how do you choose?

“It’s a question of horses for courses,” said Jill McLintock, from windows and doors company Everest.

“uPVC doors are very thermally efficient, very secure and can be double and triple-glazed but you’re limited on appearance.

"Composite doors have the look of timber but demand less maintenance and currently are the fastest growing market for entrance doors. Those seeking a traditional look tend to be very happy with timber doors, but it is a natural material and they require a bit more TLC.”

Prices vary considerably too. “A hardwood timber door can cost well over £2,000 to replace, potentially up to £3,000,” said Jill. “Composites hover around the £1,500 mark, while for a uPVC it’s somewhere around £1,000. These are of course for supplied and fitted doors, so there’s installation and guarantees in there as well.”

For a cutting-edge aesthetic, modern metal doors offer many benefits. Though far from cheap, Hormann UK builds high-strength aluminium models with heavy-duty sound insulation, sky-high energy efficiency, impressive impact resistance and anti-break-in features.

- Repair or replace?

If you’re fortunate enough to own a house with a standard-size door, you can pick up a replacement off the rack, but more unusual varieties may require more individual treatment.

“You need your door to be secure,” said Jill, “and if your door is more than 10 to 15 years old it won’t have more developed technology, like multi-point locks.”

Timber doors can warp slightly and no longer open and close properly over time, while obvious no-nos like broken glass panes require speedy attention.

Budget-depending, you may want to go bespoke. Oval-topped frames can lend a more modern look, while studded models give a heritage feel.

If possible, repairing your existing door is generally the cheaper option. Most likely this will involve scraping away old paint, filling cracks and some gluing. You could do it yourself, but these tasks require a fair amount of finesse and are usually best left to a professional. After all, you don’t want your home to end up door-less and vulnerable for any length of time.

- Colour and kerb appeal

Once you’ve settled on your door, be it old or new, you can set about making it the envy of your neighbourhood. A fresh coat of paint might be all it takes to rejuvenate your home’s exterior.

Timber must be periodically repainted; composites don’t need to be but can be; while even uPVC doors - which don’t fare well with normal paint - can gain some gloss with the right preparation.

“The main thing is to consider your surroundings,” said Sonia Pash, co-founder of interior design firm Temza Design & Build.

“Don’t choose colours in isolation. What colour is the balustrade, the fence, the house, the neighbour’s house, the neighbour’s door? Think what will look good together.”

On the other hand, your front-of-house should express something of your personality. Statement colours are increasingly popular, particularly among city-dwellers looking to stand out on identikit streets.

“They’re still a little less common than safe options like black or grey,” said Sonia, “but bold doors look just charming, and I always encourage people to go colourful. Don’t feel like it needs to relate to anything inside the house - it can absolutely be a one-off.”

- The finishing touches

“When it comes to ironmongery, choose quality over quantity,” said Sonia. “A badly carved lion head knocker that will start chipping in a year is just sad, so what you buy needs to be well-made.”

The metallic letterbox is a time-honoured staple, but unguarded letterboxes can be used by criminals to hook keys off nearby racks or tables, a process known as "fishing". Position your letterbox strategically or put a "fishing guard" on the back of the plate.

Remember to make sure all your metalwork coordinates. “You can’t buy new flat-front door numbers in brass and keep your old chrome handle,” added Sonia.

Greenery on your door adds a welcoming touch. You’ve heard of the Christmas wreath, but spring wreaths are increasingly fashionable. These circular bouquets of blooms look delightfully seasonal and Instagram-friendly.

A welcome mat is a must too, and lanterns can add a final touch of brightness.