Conservatory Conversions: A Complete Guide

Table of contents

1. Permissions and Regulations for Conservatory Conversions
2. Converting a Conservatory into an Orangery
3. Converting a Conservatory into a Sunroom
4. Converting a Conservatory into a Living Room or Family Room
5. Converting a Conservatory into a Kitchen Extension
6. Converting a Conservatory into a Bedroom
7. What the Conversion Build Involves
8. How Much Does a Conservatory Conversion Cost?
9. How to Find a Conservatory Installer
10. FAQs: Conservatory Conversions

The planning and building regs section affects all conversion types and is worth reading before focusing on a specific room type, the rules are more nuanced than most homeowners expect.

Permissions and Regulations for Conservatory Conversions

Most conservatory conversions don't require a new planning permission application, provided the work stays within the existing footprint and doesn't increase the height or materially change the external appearance of the building.

Planning Permissions

A roof replacement that doesn't alter the footprint is generally treated as a like-for-like improvement and falls within permitted development.

If you're expanding the footprint, adding a floor, or the property is listed or in a conservation area, planning permission is more likely to be needed - always check with your local planning authority before committing to a design. For a full breakdown of the planning permission and building regulations picture for new conservatory builds, see our guide to building a conservatory.

Building Regulations

Building regulations are a separate and more complex picture. The original conservatory was almost certainly built as an exempt structure - thermally separated from the house, not connected to the central heating system, and therefore not required to meet building regulations. The moment a conversion changes this status, full building regulations apply.

The conversion triggers building regs when:

• You remove the dividing door between the conservatory and the house, thermally integrating the spaces
• You connect the new room to the central heating system
• You replace the roof with an insulated solid roof that brings the thermal performance up to habitable standard

Once building regs apply, the whole structure must meet current standards for insulation (Part L), structure (Part A), fire safety (Part B), ventilation (Part F), and electrics (Part P). A completion certificate from a building control officer is issued on sign-off, and this certificate is what solicitors require when a property changes hands.

A note on foundations: Most conservatories were built on shallower foundations than a full habitable room requires. If you're planning a significant structural conversion, a structural engineer should assess the foundations before work begins. See our guide to converting a conservatory into an extension for a full breakdown of the foundation implications.

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Converting a Conservatory into an Orangery

Converting a conservatory to an orangery is the most popular type of conservatory conversion. It produces a space that sits between a conservatory and a full extension. It’s more thermally efficient than a conservatory, with a warmer, more architectural quality, while retaining substantial natural light. For many homeowners, it's the best of both worlds.

What defines an orangery:

An orangery has less glass than a conservatory. The defining characteristics are solid brick or stone pillars supporting the roof, solid perimeter walls (typically below window height), and a lantern roof - a central glazed rooflight set within a solid roof structure rather than a fully glazed ceiling.

The ratio of glass to solid wall is lower than 50% for walls and lower than 75% for the roof, which is the technical distinction from a conservatory.

What the conversion from conservatory to orangery involves:

The glazed walls of the existing conservatory are replaced with brick or stone pillar construction, reducing the glass area and bringing the thermal performance closer to that of a solid wall.

The glass or polycarbonate roof is removed and replaced with a solid insulated roof section with a central lantern rooflight. The internal wall treatment changes from the lightweight insulated boards typical of a conservatory to full plastering on solid walls.

This is a more substantial build than a simple roof swap, it involves masonry construction, which requires the existing foundations to be assessed. The result is considerably more energy-efficient, visually distinguished from a conservatory, and generally adds more value to the property.

Timescale: Typically 6-8 weeks once work begins, assuming no foundation complications.

Converting a Conservatory into a Sunroom

The terms sunroom and conservatory are used interchangeably in the UK, but in a conversion context, converting to a sunroom usually means improving the glazed structure's thermal performance without converting to masonry construction.

The result is a lighter, more open feeling than an orangery, with a higher proportion of glass.

A sunroom conversion typically involves:

• Replacing a polycarbonate or older glass roof with a modern thermally efficient glazed roof system - double or triple glazed with solar control coating
• Upgrading the wall glazing to modern double-glazed panels with low-emissivity glass
• Improving frame insulation and sealing, and adding or upgrading thermal blinds
• Extending the heating system or adding efficient electric heating

A sunroom conversion is less disruptive and less expensive than an orangery conversion because it doesn't involve masonry. The existing frame structure is largely retained and upgraded rather than partially replaced.

For homeowners who value natural light and the open, garden-connected feel of a conservatory but want it to function year-round, a sunroom conversion strikes the right balance. For homeowners primarily focused on creating a usable, well-heated room that happens to have good garden views, an orangery or solid-roof conversion will deliver better results.

Timescale: A roof-only sunroom upgrade can be completed in a few days. A full sunroom refurbishment typically takes 1-2 weeks.

Converting a Conservatory into a Living Room or Family Room

Converting a conservatory into a full living room or family room is one of the most common conversion goals. The space is large enough to function as a distinct room, it connects to the garden, and it's typically adjacent to the main living areas of the house.

Making a conservatory work as a year-round living room requires addressing the full thermal envelope: the roof (the largest source of heat loss in most conservatories), the glazing, and the thermal separation from the house.

This means either a solid insulated roof replacement or, if natural light is important, a high-performance glazed roof.

The additional considerations specific to living room use:

Flooring:

A living room needs a warmer, more comfortable floor than a tiled or concrete conservatory base. Underfloor heating beneath engineered wood or carpet makes a significant difference to comfort. This typically involves raising the floor level by 50–100mm, which affects the relationship with doorways and adjacent rooms.

Connectivity to the house:

Removing the dividing door and opening up to the main living area creates a more flowing, open-plan feel but triggers building regulations for the whole structure. If you want to keep the building regs position simple, retaining a high-quality external-spec door rather than a standard internal door maintains the thermal separation exemption while still connecting the spaces visually.

Electrical provision:

Lighting, TV points, and sufficient socket provision for a living room are a significant addition to what most conservatories have. Planning the electrical layout as part of the conversion rather than adding it retrospectively gives a much cleaner result.

For how to make the space warmer during and after conversion, see our guide on making a conservatory warmer.

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Converting a Conservatory into a Kitchen Extension

Converting a conservatory into a kitchen extension is the most complex and most regulated of the common conversion types, and for good reason, a kitchen has specific requirements around plumbing, drainage, ventilation, electrical provision, and wall-hanging capacity that a standard conservatory structure can't always accommodate.

The specific challenges:

• Wall strength: Kitchen units, worktops, and appliances require walls that can bear their weight. Most conservatory frames cannot support full wall-mounted units without structural reinforcement or replacement.

• Plumbing and drainage: Connecting a sink and dishwasher requires extending the cold water supply and waste drainage to the conservatory. The drainage in particular requires a fall to a stack or drain connection, which may need careful routing depending on the existing drainage layout.

• Ventilation: Building regulations require adequate ventilation for a kitchen, specifically, extract ventilation capable of managing cooking fumes and moisture. This is typically a ducted extract fan. If the conservatory shares a wall with the main house kitchen, extending the existing extraction may be an option; otherwise a new duct must be routed through the roof or a wall.

• Electrical provision: A kitchen requires a dedicated circuit for high-load appliances (oven, dishwasher, washing machine if included), plus sufficient ring-main sockets. This requires a qualified electrician and building regulations Part P compliance.

A kitchen extension conversion is effectively a full building regulations project, all the thermal, structural, drainage, and electrical requirements apply. It's the conversion type where getting the design right before starting work matters most, and where an architect or designer's input is likely to be worth the additional cost.

See our house extension cost guide for a comparison with starting from scratch.

Converting a Conservatory into a Bedroom

A conservatory bedroom is less common than other conversion types but suits specific situations - particularly where a ground-floor bedroom is needed for accessibility reasons, or where the conservatory is large enough to serve as an annexe.

The requirements are more demanding than for a living room because building regulations for habitable rooms used as bedrooms are more specific:

Means of escape:

A bedroom requires a fire egress window — a window that can be opened wide enough for a person to climb out in an emergency. Most conservatory glazing doesn't meet this requirement as standard, and the window or door specification must be addressed during the conversion.

Sound insulation:

Between a bedroom and an adjacent room, sound insulation requirements apply. The dividing construction between a converted conservatory bedroom and adjacent living spaces needs to meet Part E requirements.

Privacy glazing:

A bedroom with floor-to-ceiling glazing on one or more sides requires carefully considered privacy - obscured glazing, external planting, or carefully positioned screening. This is a design consideration rather than a regulatory one, but it significantly affects whether the space functions well as a bedroom in practice.

A conservatory bedroom that is fully building regulations compliant counts as a habitable room and contributes to the bedroom count that affects property valuation, worth bearing in mind when assessing the cost-benefit of the conversion.

What the Conversion Build Involves

The build process for a conservatory conversion varies significantly by conversion type, but most share a common sequence.

• Roof replacement: is almost always the first and most significant structural stage, whether that's a like-for-like roof upgrade, a solid insulated replacement, or a lantern-topped orangery roof. The roof is the element with the greatest impact on thermal performance and the one that most clearly changes the character of the space.

• Wall treatment: follows, whether that involves replacing glazed panels with masonry, re-insulating the existing walls, or upgrading the glazing specification.

• Floor treatment: comes next - building up the existing concrete slab with a damp-proof membrane, insulation, screed, and floor finish, which raises the finished level and needs careful coordination with door thresholds.

• Mechanical and electrical work: heating extension, electrical installation, plumbing for kitchen or bathroom conversions - is typically carried out in parallel with or immediately after the structural work.

• Plastering and finishing is the final stage before decoration, flooring installation, and fitting out.

A roof-only conversion can be completed in a few days. A full orangery conversion typically takes 6-8 weeks. A kitchen extension conversion is usually 8-12 weeks.

How Much Does a Conservatory Conversion Cost?

Costs vary considerably depending on the conversion type, the size of the conservatory, and the specification.

A sunroom upgrade - new roof glazing and improved heating - typically costs £5,000-£15,000. A solid roof replacement as a standalone project costs £5,000-£10,000 for most standard-sized conservatories. A full orangery conversion involving masonry work and a lantern roof typically costs £15,000-£30,000+. A kitchen extension conversion is broadly comparable with building a new kitchen extension - £20,000-£40,000+ depending on spec, kitchen fittings, and structural requirements.

For full pricing detail across different conservatory projects, see the conservatory roof replacement cost guide, and the conservatory insulation cost guide.

How to Find a Conservatory Installer

For orangery conversions and structural work, a conservatory installer who can manage the full project is usually the most practical choice.

Post your job on MyBuilder with details of your current conservatory and your conversion goal, the room type you're aiming for and roughly what you want to use it for, and specialists in your area will respond with their recommendations.

All tradespeople on MyBuilder undergo checks at registration - such as ID documents, company details, certifications for regulated jobs and skill assessments - allowing you to hire with confidence.

Find a conservatory installer near you

FAQs: Conservatory Conversions

Does Converting a Conservatory to an Orangery Need Planning Permission?

Usually not, provided the conversion stays within the existing footprint and doesn't significantly change the external appearance or height of the structure.

A like-for-like roof replacement and masonry infill within the existing footprint is generally treated as a permitted development improvement. If the conversion increases the footprint, alters the ridge height, or the property is listed or in a conservation area, planning permission is more likely to be required. Always confirm with your local planning authority before work begins.

Can I Convert a Conservatory Without Applying for Building Regs?

Only if the converted space remains thermally separate from the house - i.e., you keep an external-quality door between the conservatory and the main house and don't connect it to the central heating system.

The moment these conditions change, building regulations apply in full. Most homeowners converting a conservatory into a genuine room want to integrate it properly, which means building regs are almost always relevant.

How Long Does a Conservatory Conversion Take?

It depends heavily on the conversion type. A roof-only upgrade can be completed in a matter of days. A sunroom refurbishment typically takes 1-2 weeks. A full orangery conversion with masonry work usually takes 6-8 weeks.

A kitchen extension conversion is 8-12 weeks. You can browse photos of completed conservatory conversion projects on MyBuilder to see what different conversion types look like in practice.

Does a Conservatory Conversion Add Value?

Generally yes, particularly conversions that create genuinely usable year-round rooms and have building regulations sign-off. An orangery or solid-roof conversion that functions as an integrated room typically adds more value than an underused conservatory.

A kitchen extension conversion adds value proportionally to the kitchen improvement and additional floor space. The precise value uplift depends on your local market and how well the finished space integrates with the property.

What Is the Difference Between a Conservatory and a Sunroom?

In UK usage, the terms overlap significantly. A conservatory is technically defined as a structure with at least 50% glazed walls and 75% glazed roof. A sunroom has higher-quality glazing and typically better insulation, but still retains a primarily glazed character.

An orangery has less glass than either - solid brick or stone pillars and walls with a lantern roof - and sits between a conservatory and a full extension. In practice, many modern "conservatories" perform to sunroom standards, and the distinction is mainly architectural rather than regulatory.