By Shaun, Shelfbank Windows. Published .
If you want more space at ground level, the choice usually comes down to a conservatory or a single-storey extension. Both add a room to the house, and both can look good, but they are treated differently by building regulations and behave differently once they are built.
I build both, so I am not trying to push you one way or the other. This guide sets out the main differences so you can decide which fits the way you want to use the room.
The basic difference
A conservatory is mostly glass, with glazed walls and a glazed or lightweight roof, and is kept separate from the house by external quality doors or windows. An extension is built with solid, insulated walls and roof, like the rest of the house, with windows and doors set into it.
In planning terms they are treated the same way. Both are single-storey extensions, and both follow the same permitted development limits. Our post on planning permission for conservatories sets out those limits.
Building regulations
Conservatories
A conservatory is normally exempt from building regulations if it is at ground level, under 30 square metres, separated from the house by external quality walls, doors or windows, and has its own independent heating. The glazing and any fixed electrics still have to comply.
Extensions
An extension needs building regulations approval. That covers the foundations, structure, insulation, ventilation, drainage, fire safety and electrics. In England, the guidance in Approved Document L limits the total area of windows, roof windows and doors in an extension to 25 per cent of its floor area, plus the area of any openings the extension covers up. If you want a lot more glass than that, talk to building control early.
Comfort through the year
This is where most people make their decision. A traditional conservatory can get very hot on a sunny day and cold on a winter night, because glass lets heat in and out quickly. That is fine if you want a garden room for spring and summer, but less so if you want a room you can use every day of the year.
An extension is insulated to the same standard as a modern house, so it stays at a steadier temperature. If you want a kitchen, dining room, playroom or office, an extension is usually the better fit.
Opening up to the house
Many people want the new room to flow straight on from the kitchen or living room. With an extension, that is part of the design. With a conservatory, removing the doors between the house and the conservatory brings it under building regulations, and the conservatory may then have to meet the same energy standards as an extension.
The middle ground
If you already have a conservatory that is too hot or too cold, there is a third option: keep the base and frames and replace the roof with an insulated, solid one. That makes the room much more usable without starting again. Our post on putting a solid roof on a conservatory explains what is involved.
How to decide
- How will you use the room, and in which months?
- Do you want it open to the house or kept separate?
- How much glass and light do you want?
- Is the garden, the orientation or the neighbouring property a factor?
- Does your home have any planning restrictions, such as being listed or in a conservation area?
At the survey I will look at the space, talk through how you want to use it and give you a fixed written price for the option that suits.
Talk to Shaun
To talk through your options, see our extensions and building work, conservatories and warm roof replacements pages. I work across Oswestry, Shrewsbury and Wrexham. Call Shaun on 07815 753361 for a free site survey and a fixed written quote.
Related services: Conservatories, Warm Roof Replacements, Extensions & Building Work.