Conservatory Roof Replacement Costs UK — What to Charge in 2026

Why People Replace Conservatory Roofs

Almost every enquiry comes down to comfort. Old polycarbonate is a poor insulator — it lets heat pour out in winter and acts like a greenhouse in summer. The complaints you'll hear on the doorstep are remarkably consistent, and knowing them helps you steer the customer toward the right replacement option.

• Too hot in summer: Solar gain through polycarbonate makes the room unusable on a sunny day.
• Too cold in winter: Single-skin or thin twin-wall polycarbonate has a poor U-value, so heat escapes and condensation forms.
• Noise in rain: Rain drumming on polycarbonate is loud enough to drown out the TV — a solid or glass roof fixes this instantly.
• Leaks and discolouration: Sealant at the glazing bars perishes, panels yellow and craze, and the roof starts to leak at the ridge and box gutter.

The Three Main Replacement Options

There are three routes you'll quote, and each has a different price point, lead time and regulatory consequence. Make sure the customer understands the trade-offs before they pick — managing expectations here saves you grief later.

1. Upgrade to a Glass Roof

The simplest upgrade: swap aging polycarbonate panels for modern sealed glazed units. Specify self-cleaning, solar-control glass (such as a Pilkington Activ Blue or a Celsius-type coated unit) and you transform the thermal performance while keeping the conservatory light and airy. The frames usually stay, so it's the least disruptive option and the quickest to fit — often a single day for a standard size.

Because a glass roof is glazed in the same way as the polycarbonate it replaces, it is generally treated as a like-for-like replacement and does not change the conservatory's exempt status (more on that below). This is the option to push for customers who want a fast, lower-cost improvement and like the light a glazed roof gives.

2. Solid / Tiled Warm Roof

A lightweight tiled "warm roof" replaces the glazing entirely with an insulated, tiled structure — a proprietary system such as a Guardian Warm Roof, Leka, SupaLite or Ultraroof sits on the existing frames, packed with insulation and finished externally with lightweight tiles or slate-effect panels. Internally you get a plastered, insulated ceiling that makes the room feel like a genuine extension rather than a conservatory.

This is the most popular high-value upgrade and almost always the dearest option. It is also the one with the biggest regulatory and structural implications, because you are converting a glazed roof into a solid one — that changes the building's thermal status and adds significant weight. Do not quote this as a simple swap.

3. Hybrid (Solid with Glazed Panels or a Lantern)

A hybrid roof gives the best of both: a solid, insulated tiled roof with one or more glazed panels or a roof lantern set into it to keep natural light coming in. It's a great upsell for customers who love the warmth and quiet of a solid roof but worry the room will feel dark. Expect to price it between a full glass roof and a full solid roof, leaning toward the solid end once you add a lantern.

Conservatory Roof Replacement Prices by Size

Prices vary enormously by roof type, size and the number of facets (a Victorian conservatory with five facets costs more to roof than a square lean-to of the same floor area). The figures below are realistic supply-and-fit ranges for 2026, including the roof system but excluding scaffolding and any structural remedial work unless stated.

• Small lean-to (~3x3m): glass replacement £2,500–£4,000; tiled warm roof £6,000–£9,000.
• Medium (~3.5x3.5m): glass replacement £3,500–£5,000; tiled warm roof £8,000–£12,000.
• Large (~4x4m+): glass replacement £4,500–£6,000+; tiled warm roof £10,000–£15,000+.

A roof lantern set into a solid roof typically adds £1,200–£3,000 depending on size and spec. A fully plastered internal ceiling with insulation and a set of recessed LED downlights — usually quoted as part of a warm roof, but sometimes a separate line — adds roughly £1,500–£3,000 once you allow for the electrician, plasterer and decoration. Always confirm whether the customer's comparison quotes include the plastered ceiling, as some installers leave it out to look cheaper.

What Affects the Price

Two conservatories of the same footprint can be hundreds — sometimes thousands — of pounds apart. Survey for these factors before you commit a number:

• Roof type chosen: glass is cheapest, hybrid sits in the middle, full tiled warm roof is dearest.
• Size and number of facets: more facets, hips and glazing bars mean more cutting, more flashing and more labour.
• Structural capacity: a solid roof is far heavier than polycarbonate. The existing frames, wall plate and dwarf wall may not be rated for the load — you may need a structural assessment, a new structural wall plate, ring beam or supplementary posts.
• Glass spec: self-cleaning, solar-control and acoustic glazed units cost more than basic toughened units.
• Internal plastering and electrics: a plastered ceiling, downlights and any rewiring add a plasterer and electrician to the job.
• Scaffolding and access: two-storey-adjacent conservatories, tight side access or work over a neighbour's boundary push access costs up.
• Building control: a solid-roof conversion needs a building regs application and inspections — factor the fee and your time into the quote.

The Building Regulations Point You Must Get Right

This is where installers get caught out, so be clear with the customer from the start. Conservatories enjoy a "conservatory exemption" from building regulations provided they meet the conditions: built at ground level, under 30m², separated from the house by external-quality doors, with an independent heating system and glazing that complies with safety rules. Most conservatories qualify.

Replacing polycarbonate with glass — or new polycarbonate — is usually a like-for-like glazed replacement and does not change that exempt status. It's effectively a repair/replacement of an existing glazed roof.

Converting to a solid or tiled roof is different. Once you put a solid, insulated roof on, the structure is no longer a "conservatory" in the regulatory sense — it's closer to a single-storey extension. The conservatory exemption is lost, which means the work typically requires building regulations approval and a structural assessment to confirm the existing base, walls and frames can carry the additional dead load. The LABC (Local Authority Building Control) has issued specific guidance on exactly this point, and it's widely echoed by warm-roof manufacturers, who supply structural calculations with their systems for precisely this reason.

In practice this means the solid-roof job should include either a building notice or full plans application, building control inspections, and the system manufacturer's structural calculations. Quote it openly: it protects the homeowner, protects you, and is a genuine point of difference against a cowboy who slaps a tiled roof on with no sign-off. A customer who later sells the house may need the completion certificate, so getting it right adds real value.

Practical Quoting Tips for Installers

A conservatory roof quote goes wrong when it's priced off photos or a phone description. Survey properly and build these into your number:

• Check the structure before quoting a solid roof. Measure the existing frames, dwarf wall and base. If there's any doubt about load capacity, price in a structural check and possible wall plate or ring beam upgrade rather than discovering it mid-job.
• Separate building control as a line item. Show the regs application and inspection costs clearly so the customer sees you're doing it properly — and so you don't absorb the fee.
• Itemise the plastered ceiling and electrics. Make it obvious whether downlights and a plastered finish are included; this is the most common point of confusion when customers compare quotes.
• Confirm the box gutter and abutment. Where the conservatory meets the house, flashing and box gutter detailing is where leaks start. Note its condition and include any remedial work.
• Set glass-spec expectations. Explain the difference between basic toughened units and solar-control self-cleaning glass so the customer chooses knowingly.
• Allow for access and scaffolding. Get a scaffold quote where needed and pass it through as a separate cost rather than guessing.
• Give a written spec, not just a price. Name the roof system, glass spec, U-values and what's included. It demonstrates expertise and lifts your quote above competitors who just send a figure.

Quick Reference: Conservatory Roof Replacement Prices UK 2026