Conservatories: How to Get Them Right

ABOVE: The conservatory on this renovated property adds much-needed light to dark interiors. Read more about this project

"We’d like to build a conservatory without it looking like every other conservatory we have ever been in.” Heard it all before? Most self-builders have. The problem with getting them right is, as usual, money.

It is estimated that more than 90 per cent of conservatories added to houses in the UK are out of a catalogue — straightforward and rectangular. These uninspired – usually PVCu – additions to the home are normally fitted by a team of sound, if blinkered, functionaries, who may be good tradesmen, but are decidedly not craftsmen. Their product is usually similar — functional but lacking in flair.

So the net result, should you be thinking of having one of these additions to your home, is likely to be similar to 100,000 other ‘anywhere conservatories’ all over the country. No wonder there is a strong anticonservatory lobby: most new ones look pretty samey, and in design terms usually serve to detract from the appearance – and perhaps also the value – of the house they are meant to adorn.

But conservatories of this sort are good value and practical. Many a family has been saved an expensive move by the addition of a good-value off-the-peg conservatory. Standard ‘bolt-on’ conservatories are usually a very cheap way of gaining extra space, and dramatically cheaper than a bespoke garden room.

With a standard conservatory like this you don’t need planning permission if the structure falls within the Permitted Development (PD) rights of the house. And a further big advantage is that, providing they are not part of the heated envelope of the house – that is, you retain the wall they are built against in its entirety – conservatories like this rarely require Building Regulations consent.

So what is wrong with conservatories? And why the move towards bespoke garden rooms, which cost vastly more and nearly always require Building Regulations?

“Conservatories as we all understand them don’t really work very well in this country,” says architect Tom Drury, who specialises in small domestic work and what he calls ‘sophisticated solutions’.

He has become convinced, like many other architects, that garden rooms are far more efficient. “In this country, in a room largely of glass, and with a glass roof, you fry in the summer,” he says. “And unless you spend a fortune on heating, you freeze in the winter. In addition, standard PVCu conservatories are difficult to keep clean and there is the ever-present problem of having to manipulate fussy blinds that keep out the glare in summer.”

CLOCKWISE FROM TOP: This conservatory from Franklin Windows (0113 250 2991) matches the rest of the house perfectly (built at the same time as the new windows were installed). It’s aluminium on the outside and timber inside; a similar design will cost around £30,000 plus installation; This veranda from Countrywide (01202 725222) is a perfect compromise for those who don’t like conservatories. They typically cost £7,500; This oak frame sunroom enjoys many of the benefits of a traditional conservatory without the overheating.

However, for a garden room with a solid roof – even one added to an existing house – you will need Building Regulations consent, and probably planning permission as well. Even if the size means that you do not need planning, garden rooms can throw up problems with Building Regulations, because under normal circumstances the area of glazing should be no more than 25 per cent of the overall floor area.

Even if you have a solid wall and door between the walls of the original building and the new room, the amount of permitted glazing may well not match your require - ments. Therefore, the extra glazing has to be justified by other means. This is often possible by increasing the thermal performance of the roof, floor and walls.

So if the conservatory/garden room is large, or there is no thermal break between the house and the conservatory, then the full weight of the energy-efficiency regulations comes into effect. Basically, this means that glazing should have a maximum U-value of 1.8, which translates as argon-filled, low-E coatings and large air gaps. This will probably be more expensive than conventional walling or roofing materials.

“What it amounts to is that, providing the CO2 emissions from the building as designed are no greater than the CO2 emissions from a building of exactly the same size but which complies with minimum Building Regulation standards, then you comply,” says Building Regulations consultant Colin Williams.

So what about design? Well, you could opt for something individually designed: perhaps a contemporary frameless structure or something very much in-keeping with the rest of the house. This will have to be designed by someone who can visit your house and assess your own individual requirements. You could also be a little bit more fussy and choose a specialist conservatory company that offers something well designed and a little bit out of the ordinary — try Franklin Windows, Countrywide or Vision Group.

If you don’t fancy an enclosed space, consider a simple compromise — a covered outdoor area that’s open onto a patio or garden. Perfect to enjoy some outdoor living and the ideal solution to the traditional rainy barbecue. Whatever you choose, make sure you apply the same design principles to your conservatory as you would any other part of your house.

Further reading:

• Dormer Windows: How to Get Them Right
• A Converted Cottage with a Conservatory
• A Super Insulated Self Build with a Conservatory
• A Guide to the New Permitted Development Rules