Guardian vs SupaLite: which conservatory roof is better?

These are two of the most asked-about tiled warm roofs, and on paper they are close. Both put an insulated, tiled roof on an aluminium frame, both quote a U-value of 0.15 W/m²K as standard, and both sell only through independent installers. The differences are in the published weight, the glass options, how clearly the guarantee is set out and, above all, how easy it is to find a good installer near you.

Guardian began in Ireland and is sold through a licence network of certified fabricators and installers. SupaLite is made in Preston by SupaLite Tiled Roof Systems Ltd, a private company founded in 2009. We have not tested either roof: figures are the makers’ own unless we say otherwise.

Guardian vs SupaLite at a glance

	Guardian Warm Roof	SupaLite Tiled Roof
Maker	Guardian Building Systems Ltd (Irish origin; UK company number not confirmed)	SupaLite Tiled Roof Systems Ltd, Preston (company 06930456)
Construction	Aluminium frame; installer build-up of plywood deck, two 50mm insulation layers and 72mm insulated plasterboard	Aluminium frame, eaves ring beam and ridge; 100mm insulation between rafters plus a 25mm layer, plywood, membrane, insulated plasterboard
U-value (W/m²K)	0.15 England, 0.13 Wales, 0.12 Scotland	0.15 standard, 0.12 enhanced
Weight	No maker figure; about 55 kg/m² (ConservatoryRoofCosts.co.uk)	Under 46 kg/m² (SupaLite); 40 to 49 kg/m² on third-party sites
Roof finish	Guardian Esprit Shingle, Metrotile Shingle, Guardian Slate	ExtraLight Classic, ExtraLight Shingle, Tapco Slate
Glazed options	Guardian Solstice rooflight, VELUX roof windows	SkyVista solar control glass panels (one or two), SkyVista Glow heated glass, roof windows
Certification	LABC and HBC approved, LABSS (Scotland), BRE tested, TrustMark Scheme Provider from 2025	Stroma building control approval; LABC Registered Detail EW277 (2014 to 2016, current status not confirmed)
Guarantee	10 years product plus 10 years installer workmanship, insurance-backed (Guardian)	10 years (product page); other sources differ (see below)
Installer network	About 70 installers (ExpertSure estimate)	About 30, mostly North West (ExpertSure estimate)
Typical fitted price	£7,500 to £14,500; most 14 to 18 m² roofs £9,000 to £11,500 (ExpertSure, VAT not stated)	From £10,000 plus VAT for 10 m² (ExpertSure); £900 to £1,350 per m² installed (ConservatoryCost.com)

Which is warmer, Guardian or SupaLite?

There is nothing to choose between them on the headline figure. Both quote 0.15 W/m²K as standard, the limit Approved Document L sets for a new roof in England. Guardian publishes 0.13 for Wales and 0.12 for Scotland, which match those nations’ tighter targets, and SupaLite offers an enhanced 0.12 build. Guardian says its figures are BRE assessed.

Both have improved over time. An older Guardian brochure gave 0.18, and SupaLite’s LABC Registered Detail from 2014 stated 0.18. If someone quotes you 0.18 in 2026, ask which build-up they are fitting. On insulation, SupaLite describes 100mm between the rafters plus a further 25mm layer, and an installer’s published Guardian build-up shows two 50mm layers plus 72mm insulated plasterboard. See our guide to tiled conservatory roofs for what the roof can and cannot do for a cold room.

Weight and structure

SupaLite publishes a weight and Guardian does not. SupaLite says its roof is under 46 kg/m², adding that this may vary by roof style. Third-party sites quote 40 to 49 kg/m² for SupaLite and about 55 kg/m² for Guardian, and ExpertSure gives 18 kg/m² for Guardian’s tiles alone. On the figures available SupaLite is the lighter roof, although a third-party comparison also calls it heavier than LivinRoof, LEKA and UltraRoof.

Either way, building control will want to know your frames can carry it. LABC says frames built for a polycarbonate roof may not have enough reinforcement, and inspectors check for a steel core by drilling pilot holes or with a magnet. If there is none you may need new frames or support posts. SupaLite’s guide shows support mullions fixed inside its eaves beam for this. LABC adds that a lightweight solid roof typically adds less than 10% to the load of a glazed roof, and trial holes are usually dug to check the foundations. Our guide to whether a conservatory can take a solid roof goes through the survey.

Looks and finishes

Both look like a tiled roof from outside and give you a plastered ceiling inside.

• Guardian: Guardian Esprit Shingle in Greenstone, Coal-Black, Charcoal or Scarlet; Metrotile Shingle in seven colours; or Guardian Slate, a synthetic slate in Black, Grey, Mulberry or Terracotta.
• SupaLite: ExtraLight Classic, a recycled polymer tile in black; ExtraLight Shingle, stone-coated steel in Charcoal, Ember or Walnut; or Tapco Slate in six colours including Stone Black, Pewter Grey and Brick Red.

SupaLite’s ExtraLight Shingle is approved down to a 10 degree pitch and the Classic tile to 12.5 degrees, which helps on shallow lean-tos. Inside, SupaLite has offered a vaulted ceiling, a flat ceiling with a lighting pelmet and a tongue and groove timber-effect finish. Guardian’s ceiling is insulated plasterboard, ready to plaster.

Light: roof windows or glass panels?

SupaLite has the more developed glass option. Its SkyVista panels are solar control, self-cleaning glass fitted as one or two panels in the roof, for Edwardian, Victorian and lean-to shapes. SupaLite says they reflect up to 60% of the sun’s heat and let through up to 47% of the light (its product page says 45%). SkyVista Glow adds thermostatically heated glass, which SupaLite says costs about 9p an hour per panel at 25p per kWh. SupaLite has not published a U-value or weight for the glazed version.

Guardian offers its Solstice rooflight, a sealed glazed panel, and VELUX roof windows from centre-pivot to contemporary designs. Installers also list sun tunnels. Both approaches let light in at chosen points; neither turns the roof back into a glass one.

Guarantees, and what happens if your installer stops trading

Guardian is the clearer of the two. It 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.

SupaLite’s terms are harder to pin down. Its product page says 10 years. Green Oak, a SupaLite installer, quotes a 15-year manufacturer warranty and 25 years on tiles, while SupaLite says Tapco Slate carries a 10-year tile guarantee as standard. SupaLite also mentions an “Installer Guarantee” when an approved installer fits the roof, and ExpertSure says SupaLite does not publish its warranty terms. Ask for the actual document before you sign.

If an installer goes bust, an insurance-backed guarantee (IBG) is what keeps the workmanship cover alive: it is issued by FCA-regulated providers such as HomePro. Without one, Citizens Advice says you register as a creditor and might not get money back. Keep any deposit to 25% or less, and pay by credit card where possible for section 75 protection. Our guarantees guide explains the options.

Price and value for money

The price ranges overlap. 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. For SupaLite it reports a published price of “from £10,000 plus VAT for 10 m²”, which works out at £12,000 with VAT, although we could not find that figure on SupaLite’s own site. ConservatoryCost.com gives £900 to £1,400 per m² installed for Guardian and £900 to £1,350 for SupaLite. Green Oak, an Essex installer, quotes £1,100 to £1,300 per m² plus VAT for SupaLite.

For comparison, our 2026 range for a fitted tiled roof on a medium conservatory (about 4m x 3.5m, across four common shapes) is £7,400 to £12,100, typically about £9,600. See tiled roof costs for the extras that push a quote up.

Reported problems

These are what reviewers and review sites report, attributed to them. 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 appearing years later. Several earlier Guardian-named companies have been dissolved; the current trading name is Guardian Building Systems Ltd.
• SupaLite: its Trustpilot profile is unclaimed with no reviews, and its website displays a Google rating of 4.1. ExpertSure notes the smaller installer network concentrated in the North West. Companies House lists many regional companies using the SupaLite name, most dissolved (for example SupaLite Roof Systems Ltd, dissolved January 2025); their link to the manufacturer is not confirmed.

For both, check the installer’s own reviews and trading status on Companies House before you pay anything.

Guardian or SupaLite: which should you choose?

• There is a well reviewed installer of one brand near you and not the other: choose that one. The specs are close enough that the installer matters more.
• You want solar control or heated glass in a tiled roof: SupaLite, with SkyVista or SkyVista Glow.
• You want a clearly stated insurance-backed guarantee: Guardian, but ask to see the policy.
• You live outside the North West: Guardian is likely to have more installers nearby.
• Your conservatory is a shallow lean-to: SupaLite’s shingle is approved to 10 degrees; ask any Guardian installer what pitch they can do.

Read our Guardian Warm Roof review and SupaLite review for more on each. When you get quotes, ask each installer for the system name, the U-value in writing, who applies for building control and who backs the guarantee. Our guide to comparing quotes has the full checklist.