Conservatories & Orangeries in London

Most conservatories are permitted development under Class E of the GPDO, meaning no planning application is required. To qualify under PD: the conservatory must be single storey, not forward of the principal elevation, not exceed 50% of the curtilage, and be under 4m high at the ridge (or 3m if within 2m of a boundary). Critically, a conservatory must be thermally separated from the house by an external-quality door and have a glazed or translucent roof — if it lacks these features, it is treated as an extension and different PD rules apply. Conservation areas, listed buildings, flats and properties with exhausted PD allowances all require full planning permission.

A conservatory is exempt from building regulations if it meets all four conditions: floor area under 30m², at ground level, glazed or translucent roof (more than 75% of the roof area), and thermally separated from the house by an external-quality door and fixed glazing. If any condition is not met — for example the roof is a solid insulated structure — the project is treated as an extension and Part L (thermal), Part A (structural), Part F (ventilation) and Part O (overheating) all apply. Orangeries with solid roofs almost always require building regulations. FENSA or CERTASS registration is required for all replacement glazing work regardless of whether full building regs apply.

A lean-to conservatory (6–12m²) starts from £35,000 fully constructed. A standard P-shape or T-shape conservatory (15–22m²) typically runs £55,000–£80,000. A full-width rear conservatory (25m² plus) costs £75,000–£100,000. An orangery with solid roof, brick pillars and internal cornice: £80,000–£120,000. These are complete fixed-price figures including all groundwork, structure, glazing, doors, electrics and decoration.

A conservatory is defined by its glazed roof — more than 75% of the roof area must be translucent or transparent under planning and building regulations rules. An orangery has a solid insulated roof with a central lantern light, brick or stone pillars, and an internal architectural cornice — it is structurally and thermally much closer to a house extension than a conservatory. Orangeries perform better thermally (Year-round use without auxiliary heating is realistic), typically add more value, require building regulations (Part L assessment mandatory), and cost 20–40% more than an equivalent-size conservatory. For period London homes, orangeries typically sit better architecturally.

Key choices: self-cleaning glass (hydrophilic coating, reduces cleaning frequency on roof planes — recommended for all inaccessible roof sections); solar-control low-E units (SHGC 0.2–0.35 for south and west-facing aspects to reduce overheating); argon-filled sealed units achieving 1.0–1.2 W/m²K centre pane (vs 2.8 W/m²K for standard double); roof lanterns with structural aluminium frames and thermally broken glazing bars; bifold doors (3–7 panels, fully open for summer) or inline sliding doors (better thermal performance when closed). For conservation areas, slim-profile double-glazed units in timber or Accoya frames that replicate Victorian glazing bar proportions are typically required.

Yes, but with restrictions. In a conservation area, Class E PD rights for outbuildings and extensions remain available for rear additions not visible from the public highway. However, Article 4 Directions in many London conservation areas (Hackney, Islington, Camden, Wandsworth, Hammersmith) remove Class E rights entirely, requiring full planning for any addition. Where planning is required, conservation officers typically insist on traditional materials (brick matching the existing house, timber or Accoya frames rather than uPVC or powder-coated aluminium), Georgian-bar glazing proportions, and pitched or hipped roof forms. uPVC frames are refused in most London conservation areas. Builderr has successfully obtained planning for conservatories and orangeries in conservation areas across all 32 London boroughs.