Lean-to
A single shallow pitch off the house wall. The cheapest plan, and the only one that works under a low first-floor window or a bungalow eaves.
04What we fit
Most conservatories fail for the same two reasons.
They cook in July and freeze in January because the roof was never insulated, and they move because the base was never checked. Both are fixable — but only if somebody looks before quoting.
05The single biggest fix
Keep the frames. Replace the roof.
If the conservatory itself is sound — frames square, glass intact, base solid — the roof is almost always the only thing actually wrong with it. Swapping polycarbonate for an insulated warm roof turns a greenhouse back into a room, for a fraction of the cost of starting again.
The catch is weight. An insulated roof is heavier than the polycarbonate it replaces, so the existing frames and base have to be checked to see whether they will carry it. Sometimes they will not, and we would rather tell you that than overload a structure and hand you a worse problem.
- Existing polycarbonate
- 3.4W/m²K roof
- After conversion
- 0.18W/m²K roof
- Typical duration
- 3–5days on site
- Internal finish
- Plasteredand skimmed
Regulations
Replacing a translucent conservatory roof with a solid one is usually notifiable work and can remove the conservatory's exemption altogether. We establish which route applies at survey and put it in writing before you order anything.
Five plan shapes
The house usually decides, not taste
Edwardian
Square or rectangular with a hipped roof. Gives the most usable floor area for the footprint, because there are no cut-off corners to lose furniture in.
Victorian
A three or five-facet bay front. Softer against a period elevation, but the angled corners cost you floor space and sofas never quite fit them.
Gable
The full-height front wall carried up to the ridge. The most imposing option, and the one that needs the most careful structural check at the house junction.
Orangery
Masonry piers, a perimeter pelmet and a flat roof with a lantern. Reads as an extension rather than a conservatory — and is priced like one.
Not sure which?
Plan shape is usually decided by the house rather than by taste — where the soil pipe runs, how far the eaves overhang, where the boundary sits. The surveyor will normally narrow it to one or two options on the day.
Book a surveyEverything above ground
depends on what is under it
The bit nobody photographs
Cracked frames, doors that stop closing and roofs that leak at the ridge are usually base problems wearing a glazing costume.
On a new build we dig and pour to the ground conditions we actually find, not to a standard depth on a drawing. On an existing structure we open a trial hole before quoting a heavier roof. Groundworks are where a "from" price quietly becomes the final price — ours is fixed once the trial hole is done.
| Stage | What happens | Typical |
|---|---|---|
| Trial hole | Existing footing depth and condition confirmed | ½ day |
| Excavation | Dug to firm bearing, spoil taken away | 1 day |
| Footings | Concrete to the depth found, not a standard figure | 1 day + cure |
| Dwarf wall | Brick or block to match, cavity and DPC | 1–2 days |
| Slab | Insulation, damp-proof membrane, screed to level | 1 day + cure |
| Frames and roof | Structure erected, glazed and sealed | 2–4 days |
Planning and
regulations
General guidance, not legal advice
Often not — many conservatories fall under permitted development. But the limits are real and they bite: depth beyond the rear wall, height at the eaves, how much of the garden is being covered, and whether the property is listed, in a conservation area, or has had permitted development removed by condition. We check the constraints at survey and tell you which route you are on. Where an application is needed, we say so before you commit.
A conservatory can be exempt if it is at ground level, under the floor area threshold, mostly glazed, separated from the house by external-quality doors, and independently heated. Remove any one of those — most commonly by taking out the separating doors or putting a solid roof on — and it stops being exempt. That is not a technicality; it changes what has to be built and certified.
Usually, but not always. The existing frames and base have to carry the extra load, and on some older lightweight systems they will not. We check the footing with a trial hole and assess the frames before quoting. If it will not take it, we will say so — a roof that overloads its structure is a considerably worse outcome than the roof you already dislike.
Extending the house heating system into an exempt conservatory is one of the things that removes the exemption. With a warm roof and a properly insulated floor it becomes a heated room and is designed and certified as such. Electric underfloor heating on its own thermostat is the usual middle path — but confirm it with whoever will certify the work, not only with us.
Not legal advice
Planning and Building Regulations are decided by your local authority on the facts of your property. Everything above is general guidance to help you ask the right questions — confirm your own position with the council or your Building Control body.
—Next step
Have the structure checked before anything is priced.
Trial hole, frame assessment and a written route through planning and regulations — then a fixed price rather than a "from" figure.
Roof U-value0.18 W/m²K
Conversion3–5 days
New build3–4 weeks
PriceFixed after trial hole