Bay windows in Portsmouth
From £1,600
| Service | Typical price in Portsmouth |
|---|---|
| UPVC double glazed windows | £464 - £927 |
| Sash windows (UPVC & timber) | £927 - £2,472 |
| French & patio doors | £1,339 - £3,296 |
| Bay & bow windows | £1,648 - £3,914 |
| Secondary glazing | £361 - £979 |
Bay window replacements in Fratton, Milton and Cosham
Portsmouth’s Victorian and Edwardian terraces are dense in bay-fronted stock across Fratton, Milton and Copnor, and its interwar semis in Drayton and Cosham favour splayed bays over square. Legacy Windows introduces homeowners to three bay specialists who quote a fixed supply-and-fit price and, where the bay is load-bearing, include the structural head detail.
Why locals in Portsmouth choose Legacy Windows
- Typical 2026 pricing runs from around £1,650 for a compact three-light UPVC square bay to £3,915 for a splayed aluminium replacement.
- All matched installers are FENSA or CERTASS registered, and load-bearing bay heads are covered by a separate Building Regulations notice with structural calculations.
- Coastal-grade fittings and marine-quality gaskets are specified as standard on our Portsmouth panel, since salt spray finds any weakness quickly.
- Every unit hits a whole-window Uw of 1.4 W/m2K or lower under Part L 2022, with self-cleaning coatings offered on exposed south-facing bays.
- Colour matching for stucco cills, heritage cream and anthracite grey is itemised in every quote.
Areas we cover around Portsmouth
Bay briefs concentrate in PO1, PO2 and PO4, covering Fratton, Milton, Copnor and Baffins. Cosham and Drayton on the mainland see splayed interwar bays and postwar box bays. Requests from Havant, Waterlooville, Gosport and Fareham are handled by the same Hampshire fabricators. Any brief inside the twenty-three conservation areas is flagged so the streetscape and glazing bar rhythm are preserved.
Frequently asked questions
Is Building Regulations sign-off needed for a bay window replacement in Portsmouth? Yes if the bay carries the wall above, which is common on Victorian terraces in Fratton and Milton. A lintel and structural calculation is required in addition to the FENSA glazing notice.
Can I upgrade a two-light bay to a three-light unit? Only if the opening size stays the same. Changing the outer footprint alters the elevation and needs planning permission. On an Article 4 street in Southsea or Old Portsmouth the answer is almost always no.
What thermal performance should I expect? A modern replacement bay in Portsmouth typically achieves a whole-window Uw around 1.2 to 1.3 W/m2K using warm-edge argon-filled units, comfortably inside Part L 2022.
Windows and doors in Portsmouth - local context
Terraced streets across Southsea and Fratton, Victorian villas in Old Portsmouth, plus postwar rebuild in the docks area after heavy WWII bombing.
Dominant era of housing stock: Victorian to Edwardian, plus significant postwar reconstruction.
Heritage note: 23 conservation areas including Old Portsmouth and Southsea.
- Southsea
- Old Portsmouth
- Cosham
- Drayton
- Milton
Postcodes we cover in Portsmouth
- PO1
- PO2
- PO4
- PO5
- PO6
Not seeing your postcode? Request a quote anyway - we likely still cover it.