Guardian vs LEKA: which conservatory roof is better?

LEKA and Guardian both sell lightweight tiled warm roofs through networks of independent installers, but they are built from different materials. Guardian uses a lightweight aluminium frame. LEKA, a Cardiff company founded in 2015, uses a patented frame of GRP (glass reinforced plastic) with no aluminium, steel or timber in it. On the published figures LEKA is lighter, claims a lower U-value and offers a much longer product warranty; Guardian has the longer history and a clearly stated insurance-backed guarantee.

We have not tested either roof. Most of the figures below are the makers’ own claims, and several LEKA figures come only from installers or third-party sites, so we label them.

Guardian vs LEKA at a glance

	Guardian Warm Roof	LEKA Warm Roof
Maker	Guardian Building Systems Ltd (Irish origin; UK company number not confirmed)	Leka Systems Ltd, Cardiff (company 09504332); made by UK manufacturing partners
Construction	Lightweight aluminium frame; installer build-up of plywood deck, two 50mm insulation layers, 72mm insulated plasterboard	Patented GRP ring beam, rafters and ridge; rigid PIR insulation core, LEKA external boards, insulated internal boards or plasterboard
U-value (W/m²K)	0.15 England, 0.13 Wales, 0.12 Scotland	From 0.10 depending on specification (LEKA); installers and third parties quote 0.12 to 0.15
Weight	No maker figure; about 55 kg/m² (ConservatoryRoofCosts.co.uk)	No maker figure; about 34 kg/m² (third-party sites)
Roof finish	Guardian Esprit Shingle, Metrotile Shingle, Guardian Slate	Tapco Slate, Britmet LiteSlate, Metrotile shingle, Britmet tile
Glazed options	Guardian Solstice rooflight, VELUX roof windows	LEKA Skylite glazed section, tailored to parts of the roof
Certification	LABC and HBC approved, LABSS (Scotland), BRE tested, TrustMark Scheme Provider from 2025	MFA Building Control type approval with a certificate per installation; GRP to BS EN13706; JHAI approved (per Modplan)
Guarantee	10 years product plus 10 years installer workmanship, insurance-backed (Guardian)	40-year component warranty and 40-year tile warranty; parts not supplied by LEKA excluded
Installer network	About 70 installers (ExpertSure estimate); 100,000+ roofs fitted (Guardian claim)	350+ trained installers; 10,000+ roofs fitted (LEKA claims)
Typical fitted price	£7,500 to £14,500 (ExpertSure, May 2026, VAT not stated)	No LEKA price found; ExpertSure’s general tiled figure for a 4m x 4m Victorian is £8,000 to £12,000

Which is warmer, Guardian or LEKA?

LEKA claims the lower figure. It says U-values are available from 0.10 W/m²K depending on specification. Modplan, which sells LEKA roofs, quotes 0.12 for conservatories, and other sites quote 0.15, so ask what your build will actually achieve. Guardian quotes 0.15 for England, 0.13 for Wales and 0.12 for Scotland, which it says are BRE assessed, and each matches that nation’s building regulations limit for a new roof.

LEKA also argues its GRP frame avoids the cold bridging that aluminium can cause. That is the maker’s claim rather than a tested comparison. In practice the gap between 0.10 and 0.15 is small next to the heat lost through the conservatory’s walls, windows and floor, so either roof is a large step up from glass or polycarbonate. Our guide to tiled conservatory roofs explains what a solid roof changes.

Weight and structure

Neither maker publishes a weight per square metre. Third-party sites put LEKA at about 34 kg/m² and Guardian at about 55 kg/m², which would make LEKA the lighter by a clear margin. LEKA’s own wording varies: its home page says the roof weighs about 10% to 12% of the glass roof it replaces and around half of competitor systems, while its installer guide says it is of similar weight to, or lighter than, a glass roof.

The fixing details differ too. LEKA’s GRP ring beam sits directly on the window frames with no packers and is screwed up through the frame heads. Guardian fixes through a 70mm x 60mm timber packer sealed to the window heads. Both use tie bars where specified.

Whatever the weight, building control will check your frames. LABC says frames built for polycarbonate may lack the steel reinforcement for a heavier roof, and inspectors test with pilot holes or a magnet. LEKA’s guide says glazed walls correctly specified for the original glass roof should cope. Our guide to whether a conservatory can take a solid roof covers the survey.

Building control and certification

Both routes need building control. LEKA holds a type approval from MFA, a registered building control approver, and says you will get a building control certificate on every LEKA installation. Some of LEKA’s marketing describes MFA approval as making the roof exempt, but its own FAQ is clear that you still need building control involvement, approval and certification.

Guardian says it has been approved by building control since 2006 and holds LABC and HBC approvals, with LABSS approval for Scotland. Some Guardian reviewers on Trustpilot say their installer never obtained the certificate, so with either brand, write into the contract who applies and when you get the certificate. Our building regulations guide explains the process.

Looks and finishes

Both give a tiled look outside and a plastered ceiling inside.

• Guardian: Guardian Esprit Shingle (Greenstone, Coal-Black, Charcoal, Scarlet), Metrotile Shingle in seven colours, or Guardian Slate (Black, Grey, Mulberry, Terracotta).
• LEKA: Tapco Slate, Britmet LiteSlate, Metrotile shingle or Britmet tile. LEKA says there are several colours but does not list them; Britmet lists seven LiteSlate colours and Tapco stocks eight.

Inside, Guardian uses insulated plasterboard ready to plaster, and LEKA uses its own insulated internal boards or plasterboard, skimmed.

Light: roof windows or glazed sections

Guardian offers its Solstice rooflight, a sealed glazed panel, and VELUX roof windows from centre-pivot to contemporary designs; installers also list sun tunnels. LEKA offers Skylite, a glazed section it says can be tailored to suit areas of the roof. If you want opening roof windows for ventilation, ask a LEKA installer what is possible; Guardian lists them as standard options.

Guarantees, and what happens if your installer stops trading

LEKA offers the longest product warranty we found: 40 years on LEKA components and 40 years on tiles. It excludes any products in the roof that LEKA did not supply directly, so ask which parts of your build are covered.

Guardian lists a 10-year product guarantee plus a 10-year workmanship guarantee from the certified installer, and says the cover is insurance-backed if the installer ceases trading.

The difference matters. A product warranty covers components; a leak caused by poor fitting is workmanship, and that guarantee comes from the installer. If the installer goes bust, an insurance-backed guarantee (IBG) from an FCA-regulated provider such as HomePro is what keeps that cover alive. We did not find insurance backing described for LEKA installs, so ask each LEKA installer whether they provide an IBG. Keep deposits to 25% or less and pay by credit card where you can.

Price and value for money

ExpertSure puts Guardian at £7,500 to £14,500 fitted, with most 14 to 18 m² Edwardian or Victorian roofs at £9,000 to £11,500, and ConservatoryCost.com gives £900 to £1,400 per m² installed. We found no LEKA-specific price. ExpertSure’s general figure for a tiled roof on a 4m x 4m Victorian conservatory (a 16 to 18 m² roof) is £8,000 to £12,000.

Our own 2026 range for a fitted tiled roof on a medium conservatory (about 4m x 3.5m) is £7,400 to £12,100, typically about £9,600. See tiled roof costs. Because neither brand publishes prices, the only way to compare value is quotes for the same size, shape and specification.

Reported problems

These are reports from reviewers and review sites, attributed. We have not verified individual cases.

• Guardian: Guardian Building Systems scores 3.3 out of 5 from 21 Trustpilot reviews (checked 27 September 2026). Low-star themes include installers going into liquidation and leaving customers without recourse, with reviewers saying Guardian told them responsibility lay with the installer; building control certificates not obtained; and leaks, staining, condensation and tile fading years after fitting.
• LEKA: we found no Trustpilot profile for LEKA, and the main homeowner forums blocked our checks, so we have no pattern of complaints to report. That is not the same as having none. LEKA’s installation and network figures are its own claims and have not been independently verified.

Guardian or LEKA: which should you choose?

• Your frames are borderline for weight: LEKA is lighter on third-party figures, but get a survey either way.
• You want the lowest U-value: LEKA, if the installer confirms 0.10 or 0.12 for your build in writing.
• You want a long product warranty: LEKA’s 40 years, checking what is excluded.
• You want a stated insurance-backed guarantee: Guardian, but ask to see the policy.
• You want opening VELUX windows: Guardian lists them as standard.

Read our Guardian Warm Roof review and LEKA review for more on each. When you get quotes, ask each installer for the U-value in writing, who applies for building control, and who backs the workmanship guarantee if they stop trading. Our guide to comparing quotes has the full list.