Window & double glazing installers in Cornwall

67 companies · 15 towns & cities

Cornwall has 67 active window and glazing businesses on the Companies House register. Choose a town below to see the companies listed there, or request free quotes from FENSA or Certass registered installers covering your postcode.

Why Cornwall homeowners are upgrading their windows

Cornwall took 1,325mm of rain and 6 frost days in 2025 — the freeze / thaw cycles that lift seals, warp frames and let moisture creep in behind old glazing. Across the county's 251,477 households, 86% live in a house (detached, semi or terraced) — that's a lot of Cornwall homes with 8 – 12 windows each, most fitted with early double-glazing units that are well past their sealed-argon life.

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Free quotes below from FENSA / Certass installers active in Cornwall — no obligation, most respond within 48 hours.

Rainfall1,325mm

Frost days6

Peak gust95km/h

Temp range-1.7° to 26.9°C

Households251,477

Houses (det + semi + terraced)86%

Flats8.3%

Weather: Open-Meteo historical archive, 2025 daily readings for Cornwall.Housing: ONS Census 2021 (tables TS041 households, TS044 accommodation type), aggregated across Cornwall's local authorities.

Largest towns in Cornwall

Truro18 companies Newquay12 companies Penzance6 companies Camborne5 companies Helston5 companies Redruth5 companies Falmouth4 companies Cornwall2 companies Penryn2 companies St Ives2 companies Threemilestone Truro2 companies Hayle1 company

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All towns in Cornwall

Truro (18)Newquay (12)Penzance (6)Camborne (5)Helston (5)Redruth (5)Falmouth (4)Cornwall (2)Penryn (2)St Ives (2)Threemilestone Truro (2)Hayle (1)Isles Of Scilly (1)St. Agnes (1)St. Just (1)