Quick takeaways on conservatory replacement
- A new conservatory can cost from £8,000,
- A conservatory roof replacement is often the most affordable way to improve an existing conservatory, costing from £2,000.
- Planning permission is not always required, but it depends on the conservatory's size, location, and height.
An older conservatory can be a bonus when you move into a new home – or a bit of a headache. It may offer extra space and better garden access, but if it is cold, damp, dated, or too hot in summer, it can quickly become a room you avoid rather than enjoy.
The good news is that you have options. You could replace the conservatory roof, upgrade the existing structure, or remove it entirely and build a more permanent extension in its place. For many homeowners, a conservatory roof replacement is the most practical first step, offering a less disruptive and more affordable way to make the space warmer, quieter and more usable all year round.
How much does a conservatory conversion cost?
The cost of a conservatory conversion can vary widely. A simple roof replacement may cost a few thousand pounds, while a full replacement extension can cost tens of thousands. The biggest factors are the size of the conservatory, the condition of the existing structure, the type of roof, and whether any structural work is required.
As a rough guide, you might expect to pay:
| Type of conservatory work | Typial cost range* | What this usually covers |
|---|---|---|
| Polycarbonate conservatory roof | £2,000 - £4,000 | A like-for-like or basic replacement roof, usually the lowest-cost option |
| Gass conservatory roof replacement | £3,000 - £5,000 | Replacement glazing, with costs varying depending on size and glass specification |
| Tiled conservatory roof replacement | £4,000 – £6,000 | A more insulated roof option, often with internal finishing and possible structural checks needed |
| Lean-to uPVC conservatory | £8,000 – £17,000 | Roof, floor, glazing, plastering, electrics and internal finishes |
| Basic uPVC conservatory | £10,000 – £15,000 | Roof, floor, glazing, plastering, electrics and internal finishes |
| Mid-range aluminium conservatory | £20,000 – £40,000 | Roof, floor, glazing, plastering, electrics and internal finishes |
| Bespoke timber conservatory | £45,000+ | Roof, floor, glazing, insulation, plastering, electrics and internal finishes |
| Replacement single-storey extension | £1,000 – £2,500 per m², excluding VAT | A more permanent rebuild, usually involving foundations, structure, insulation and Building Regulations approval |
* Replacement roof costs and conservatory costs from Ideal Home.
Costs can rise if the conservatory is large, access is difficult, the existing base is poor, structural calculations are needed, or you choose higher-spec finishes such as roof lanterns, aluminium glazing, underfloor heating, or bespoke doors.
It is also worth budgeting for extras such as skip hire, electrics, decoration, Building Control fees, structural engineering advice, and VAT.
Conservatory roof replacement cost
A conservatory roof replacement is often a popular option because it tackles one of the biggest issues with older conservatories: poor temperature control.
Many older conservatories have polycarbonate or basic glass roofs, which can lose heat quickly in winter and make the space uncomfortably hot in summer. They can also be noisy in heavy rain and may become discoloured, damaged, or leaky over time.
Replacing the roof with a more insulated option can make the room feel much more comfortable and connected to the rest of the home, without necessarily demolishing the whole structure. It can also be part of wider energy efficiency improvements, especially if you’re already looking at ways to reduce heat loss, improve insulation, or make your home cheaper to run.
Conservatory roof replacement options
Polycarbonate roof replacement
Polycarbonate is a lightweight, clear plastic roofing material and is usually the cheapest option for a conservatory roof replacement. It may be a good choice if you simply need to replace a damaged or leaking roof on a tight budget.
However, while polycarbonate is affordable, it is not usually the best option if you want the room to feel warm, quiet, and comfortable year-round. It can lose heat more quickly than more insulated roof options and may be noisier in heavy rain.
A polycarbonate roof replacement may cost around £2,000–£4,000, depending on size and specification.
Glass roof replacement
A new glass roof can improve the appearance of the conservatory and help maintain the room's bright, open feel. Modern glazing can perform much better than older glass, especially if you choose solar-control or thermally efficient glass.
A glass conservatory roof replacement may cost £3,000–£5,000. However, this depends on the roof size and the type of glazing used.
Solid or tiled conservatory roof replacement
A solid or tiled roof is often the best option if you want the conservatory to feel more like a year-round living space. It can improve insulation, reduce glare, and make the room quieter in wet weather.
This is usually more expensive than replacing like-for-like with glass or polycarbonate, and you may need structural checks to confirm the existing frames and base can take the extra weight.
Depending on the size, insulation, lighting, and roof finish, solid or tiled conservatory roof replacements may cost between £4,000 and £6,000.
Is replacing a conservatory roof worth it?
Replacing the roof can be worth it if the rest of the conservatory is in good condition. It can be a sensible middle-ground option if you want to improve the space but do not have the budget for a full extension.
A new roof may help with:
- Heat loss in winter
- Overheating in summer
- Rain noise
- Leaks
- Glare
- Condensation
- General appearance
- Making the room feel more connected to the house
However, a new roof will not solve every problem. If the frames are poor, the floor is cold, the base is failing, or the room has damp issues, the project may need more than a roof replacement. In some cases, it may be better to remove the conservatory and start again.
Can you convert a conservatory into a proper room?
You can often improve a conservatory so it feels more like a proper room.
A basic conservatory is often designed differently from a full extension. It may have lighter foundations, more glazing, less insulation and thermal separation from the main house. If you want it to be an open-plan part of your home, it will usually need to comply with stricter Building Regulations.
A full conservatory conversion may include:
- Replacing the roof with an insulated solid or tiled roof
- Insulating or replacing the floor
- Building up dwarf walls
- Replacing old glazing
- Improving ventilation
- Adding heating with proper controls
- Upgrading electrics and lighting
- Plastering and decorating
- Checking the foundations and structure
- Applying for Building Regulations approval where needed
This can make the room more comfortable and attractive, but it is important to understand what the existing conservatory can safely support before spending money on finishes.
Converting a conservatory to an extension
Converting a conservatory into a single-storey extension is a bigger project. In many cases, it may mean removing most or all of the existing conservatory and building a new extension on the same or similar footprint.
This may be the better option if:
- The conservatory is old, damp, or poorly built
- The foundations are not suitable
- You want an open-plan kitchen or dining space
- You want to remove the external doors between the house and the conservatory
- You want a room that performs like the rest of the house
- You are planning a long-term renovation rather than a short-term fix
Replacing a conservatory with an extension will usually cost much more than replacing the roof. A typical single-storey extension can cost around £1,000–£2,500+ per m², depending on specification, location, access, and complexity.
Demolishing a conservatory and making good the back of the house
You may decide not to keep the conservatory at all. If the space is damp, poorly built, or blocks natural light, removing it can improve the layout and appearance of the back of the house.
This type of project may involve:
- Dismantling and disposing of the conservatory
- Making good brickwork, render or external walls
- Installing new French doors, sliding doors or bifold doors
- Repairing or replacing steps, patio areas or drainage
- Adjusting internal layouts
- Making the rear elevation look finished and intentional
This can be a good option if you would rather improve the existing house than spend money upgrading a conservatory that is unlikely to perform well.
What affects conservatory conversion costs?
Several factors can affect the final price of a conservatory conversion.
Size of the conservatory
The larger the conservatory, the more materials and labour will be needed. Roof area, floor area, and glazing all affect cost.
Condition of the existing structure
If the frames, roof, base, or walls are in poor condition, a simple upgrade may not be enough. Structural movement, damp, failing seals, or poor foundations can all add cost.
Structural work
If you’re removing walls, creating a wider opening, or changing the load on the conservatory frame, you may need a structural engineer and Building Control approval.
Insulation
A room used year-round needs proper insulation. This may include the roof, walls, and floor.
Glazing and doors
Replacing old frames or adding new bifold, sliding, or French doors can increase the budget, but may also improve the look and usability of the space.
Heating and electrics
Radiators, underfloor heating, sockets, lighting, and electrical upgrades all add to the overall cost. Any electrical work should be carried out safely and certified where required.
Finishes
Plastering, flooring, skirting, decoration, and blinds can make a big difference to the final look, but they should be included in the budget from the start.
How to keep costs under control
Before you commit to a conservatory conversion, be clear about what problem you are trying to solve. Are you trying to stop leaks? Improve insulation? Create a proper dining room? Open up the kitchen? Add value before selling?
Once you know the aim, it’s easier to choose the right level of work.
To keep costs under control:
- Get at least three written quotes
- Ask each builder to quote on the same scope of work
- Check whether VAT is included
- Ask whether Building Control fees are included
- Budget for a contingency of at least 10%
- Check whether the existing structure is suitable before choosing finishes
- Avoid spending heavily on a conservatory that has poor foundations or failing frames
- Choose a qualified, experienced builder for structural work
A cheaper quote isn’t always better if it leaves out important items such as insulation, plastering, structural checks, waste removal, or Building Control.
Do you need planning permission for a conservatory conversion?
Conservatories usually follow the same planning rules as single-storey extensions. This means you may not need to submit a full planning application if the work falls within permitted development rights.
As a general guide, planning permission may not be needed if the conservatory:
- Does not extend more than 6 metres from the rear of an attached house, or 8 metres from a detached house
- Is single-storey and no more than 4 metres high
- Is no more than 3 metres high if it is within 2 metres of a boundary
- Does not cover more than 50% of the land around the original house
- Is not being built on a listed building or a home in a conservation area, Area of Outstanding Natural Beauty, or other protected location
However, the rules can vary depending on your property, previous extensions, and local restrictions. If you’re converting an existing conservatory, replacing the roof or rebuilding it as an extension, it is always worth checking with your local planning authority before work starts.
You may also want to apply for a Lawful Development Certificate. This isn’t the same as planning permission, but it gives formal confirmation that the work is lawful, which can be useful if you sell your home in the future.
Do Building Regulations apply?
Building Regulations are separate from planning permission. Even if you don’t need planning permission, you may still need Building Regulations approval.
A conservatory is normally exempt from Building Regulations if it is:
- Built at ground level
- Less than 30 square metres in floor area
- Single storey
- Separated from the house by external-quality doors, walls or windows
- Heated independently, with separate temperature and on/off controls
- Fitted with glazing and electrics that meet the relevant requirements
If you remove the doors between the house and the conservatory, create a large structural opening, or turn the conservatory into an open-plan room, Building Regulations approval will usually be required.
Building Regulations may also apply if you replace a lightweight glazed roof with a solid roof, as the existing structure must be able to support the extra weight and meet the required thermal performance standards.
Before starting work, it is worth checking the latest guidance on the Planning Portal, as it covers both planning permission and Building Regulations for conservatories. You should also check with your Local Authority, as it is ultimately the homeowner’s responsibility to ensure the necessary approvals are in place.
Finding the right builder
A conservatory conversion can look simple, but it often involves several parts of the home – structure, roofing, glazing, electrics, heating, insulation, and drainage. That’s why it’s important to use a builder who understands both the practical work and the necessary permissions.
Our members are professionally vetted and their work inspected before they can join the FMB, giving you extra reassurance when choosing someone to carry out building work. For a project that could affect the layout, value, and performance of your home, that peace of mind can make a real difference.
Frequently asked questions about replacing conservatories
How much does a conservatory roof replacement cost?
A conservatory roof replacement may cost from around £2,000 for a basic polycarbonate replacement to £4,000 plus for a solid or tiled roof. The final cost depends on the roof size, materials, insulation, structure, internal finishes, and whether Building Regulations approval is required.
Is a conservatory roof conversion cheaper than an extension?
Usually, yes. A conservatory roof conversion is normally cheaper than replacing the whole conservatory with a new extension. However, if the existing base, walls or frames are poor, it may be better value to rebuild properly rather than upgrade a failing structure.
Can I put a solid roof on my conservatory?
In many cases, yes, but the existing structure must be checked first. A solid roof can be heavier than a glass or polycarbonate roof, so the frames, walls, and foundations need to support it. Building Regulations may also apply.
Can I remove the doors between my house and conservatory?
If you remove the external-quality doors, windows, or walls that separate your conservatory from the main house, the space may no longer be treated as a separate conservatory. Instead, it may be classed more like an extension, which usually means Building Regulations approval will be needed.
This is because the conservatory would no longer be thermally separated from the rest of the home. You may need to upgrade the insulation, glazing, structure, heating, and ventilation so the space meets the required standards.
Before removing any doors or creating an open-plan layout, check the latest guidance on the Planning Portal and speak to your Local Authority Building Control team. It is ultimately the homeowner’s responsibility to ensure the necessary approvals are in place before work starts.
Can I convert my conservatory into a kitchen extension?
Possibly, but this is usually a more complex project. Kitchens need proper insulation, ventilation, electrical systems, plumbing, heating, and Building Regulations approval. In many cases, replacing the conservatory with a new extension may be more practical than adapting the existing structure.