Every house has them - those messy rooms or examples of bad taste that cost you dearly when it comes time to sell.

So whether it's a replacing a conservatory or redesigning the space under the stairs, here's what you can do about them...

The 'naff' conservatory

Usually containing an abandoned exercise bike, cat litter trays and mounds of laundry, nothing puts off a viewer like a badly maintained, cheap conservatory.

In fact, House Buyer Bureau recently published research showing a 'naff' conservatory could knock £15,000 off the value of your house.

The answer is to replace it, possibly with one of the Victorian-style orangeries on the market, remembering to install underfloor heating to keep the room warm in winter and fit glass with a special low emissivity coating to control the heat in summer.

A boring home office

Covid is to blame for this one. Since the pandemic made working from home 'normal', our spare bedrooms have been turned into bland, utilitarian outposts of the office.

Don't stand for it: change that room into a stylish mini-library. Shabby chic is the most popular look, according to Tradebase, the home improvement specialist, so think burgundy walls and heavy rugs.

Put in floor-to-ceiling shelving, but don't fill every shelf. Use spare space for displays of family snaps and mementos — it's the perfect spot for the old school photo.

Put a table with a laptop in the middle of the room and add your favourite comfy armchair next to a standard lamp in the corner. A library ladder will set off the whole look.

The tip under the stairs

It's where the children chuck their school bags, where golf clubs lie forgotten or where the battered spare chairs for the dining table end up.

There's no getting away from it, in most homes 'under the stairs' is a bit of a tip. Yet the area doesn't have to be.

Laura Gibson, 42, put in a bookshelf and seating with cushions in the understairs space at her home in Tunbridge Wells, Kent, to make a cosy little snug that she shares with her children, Teddy and Effie, and dog Rufus. 

She even knocked a window space into the wall to ensure there was enough light to read.

'It's so nice to sit here quietly while the rest of the family are buzzing around me,' she says.

A shabby fish pond

Nothing says boring suburbia louder than a goldfish pond. 

Apart from being naff, it can be dangerous for young children and is a constant source of stress. 

Will the fish die when the pond freezes over during an icy spell? Will a heron poach one?

Yet water adds sparkle to a garden, so what to do? Self-contained water features are the answer. 

These take up little space, are easy to install and can be put away in winter. 

They can be solar powered or plugged into the mains electricty — as long as you have an outdoor socket nearby. 

Some can simply be positioned, plugged in and turned on — it's that easy. 

Prices vary, but you can buy a water feature for about £80. 

They mask road noise, improve your air quality and attract wildlife. That sure beats a suburban goldfish pond.

The teeny-weeny garage

Was there ever a more pointless addition to the family home than the integral garage?

According to a survey by the Door And Hardware Federation, three quarters of garages in new-build homes are simply too small for modern cars.

And it is common knowledge that these structures — garages attached to a home — are used as storage. 

Best, then, to turn them into something else: perhaps a man cave, a dining room or a playroom.

Joy Heath, 58, was inspired to convert her double garage by her visit to the Housebuilding and Renovation Show.

The result is a perfectly formed mini-cinema. 

Electricians installed the projector monitor and speakers; a window was blocked off; special materials were used to damp down the sound; and platforms were built for the banks of authentic cinema seating.

There is even a popcorn machine to add flourish to the silver-screen experience. It cost Joy £50,000, but has added easily that much to the value of the house.

'More than that, it has been great fun,' says Joy, who lives in the Cotswolds. 'Every six weeks my friends come around for a cinema and pizza night. The cinema has put a new spin on my social life.'