A conservatory adds usable floor space and floods the adjoining room with light, but the cost range is enormous. A basic lean-to on a modest rear extension can be done for £8,000–£12,000; a large Victorian-style structure with a solid or tiled roof can reach about £38,000, and a P-shape or orangery £50,000 or more. Understanding what drives those figures helps you plan a project that suits your budget and your home.

Quick Cost Guide

Conservatory typeTypical floor areaSupply & fit (polycarbonate or basic glass roof)Supply & fit (solid/tiled roof)
Lean-to (mono-pitch)8–12 m²£8,000–£18,000£15,000–£28,000
Victorian (3- or 5-facet)10–16 m²£12,000–£25,000£20,000–£38,000
Edwardian (rectangular)10–18 m²£10,000–£22,000£18,000–£35,000
P-shape (combination)16–28 m²£18,000–£35,000£28,000–£50,000
Orangery12–24 m²Not applicable£25,000–£60,000+

Prices assume a standard brick or block dwarf wall base, uPVC or aluminium frame, double-glazed units, and a concrete or paving slab floor. Prices exclude internal fit-out (flooring, heating, décor).

Types of Conservatory

Lean-To

The simplest design, a single-pitch roof slopes away from the house wall. Well suited to bungalows, terraces, or properties where ridge height is limited by a neighbouring structure or planning constraint. The clean lines also suit contemporary homes.

  • Maximum height is straightforward to control.
  • Most economical to build and to maintain.
  • Less natural light than a pitched structure.

Victorian

Characterised by a steeply pitched roof, a multi-facet (usually 3 or 5 sided) bay front, and ornate ridge details. Victorian conservatories suit traditional UK housing styles, late-Victorian terraces, Edwardian semis, and interwar detached houses all look appropriate with this style.

  • The angular bay front reduces internal floor area compared with an Edwardian of the same footprint.
  • Ridge crestings and finials add character but can trap moss and lichen.

Edwardian (Georgian)

A square or rectangular footprint with a hipped or gabled pitched roof. The rectangular plan maximises usable floor area and furniture placement. One of the most practical styles for a family room or garden room.

  • Symmetrical and relatively simple to construct.
  • Roof pitch can be adjusted to allow roof windows.

P-Shape

A combination of a lean-to attached to a Victorian or Edwardian section, forming a P when viewed from above. Suits larger properties where different zones are needed (e.g. dining area in the rectangular section, sitting area in the lean-to leg).

  • More complex to build; higher cost and more potential for leaks at the junction.
  • Can give a large total floor area, but the permitted development limits on depth and on garden coverage still apply.1

Orangery

Technically distinct from a conservatory: an orangery has a solid flat lantern roof with glazed lights, brick or rendered piers rather than a glazed frame, and a flat soffit around the perimeter. The result is a more robust, room-like structure that blurs the line between extension and conservatory.

  • U-values can meet full Part L compliance, making it habitable as a permanent living space.
  • Building Regulations approval is usually needed: with a largely solid roof and walls, an orangery is normally treated as an extension rather than an exempt conservatory, so check with building control first.
  • Cost reflects the additional masonry and structural work.

Roof Options

The roof determines whether your conservatory is comfortable to use year-round.

Polycarbonate, cheapest; poor insulation; overheats in summer, loses heat rapidly in winter. Few installers recommend it for new builds in 2026; it is mostly sold as a replacement for existing roofs.

Double or triple glazed glass, better than polycarbonate; self-cleaning coatings reduce maintenance; solar-control glass (low-e coatings) limits overheating. A fully glazed roof is still warmer in summer and colder in winter than a solid roof.

Solid/tiled roof, insulated panel or tiled over a structural frame. Where the conservatory counts as an extension, Approved Document L limits a new roof to a U-value of 0.15 W/m²K.2 Transforms the space into something approaching a proper room. Adds £5,000–£15,000 over a glass roof depending on size.

Roof lantern (orangery-style), fixed glazed lantern within a solid flat roof; good balance of light and insulation.

Frames: uPVC vs Aluminium

FactoruPVCAluminium
CostLower (typically 15–25% less)Higher
SightlinesBulkier profilesSlimmer, more contemporary
Colour optionsWhite, cream, woodgrain foils, some coloursAny RAL colour; dual-colour inside/out
Lifespan20–30 years40+ years
MaintenanceLowVery low

For traditional properties, uPVC in white or woodgrain is visually acceptable. For contemporary or premium projects, aluminium is the better choice.

Base and Floor

The conservatory sits on a concrete strip or raft foundation. A dwarf brick or blockwork wall (typically 600–900 mm high) is common, it improves insulation and privacy compared with a full-height glazed frame. The internal floor is usually laid over a concrete slab with underfloor insulation; popular finishes include porcelain tile, luxury vinyl tile (LVT), or engineered timber.

Budget roughly £300–£1,500 for internal flooring in a standard 12 m² conservatory, plus any levelling or subfloor preparation: fitted LVT typically runs £25–£70 per m², and porcelain tiling roughly £85–£120 per m² including the tiles.

Heating

A conservatory connected to the central heating system performs best. Options:

  • Underfloor heating (UFH): £1,200–£3,000 for a 12 m² room; the most comfortable option for a solid-roof conservatory.
  • Radiator extension: adding a radiator to the existing circuit costs £300–£700 per radiator.
  • Electric panel heater or infrared: low installation cost but higher running cost; suitable for occasional use.

Extending the house’s central heating into a conservatory takes it out of the Building Regulations energy exemption: Approved Document L then treats it as an extension, with full insulation standards for its walls, roof and glazing.2 If you want it heated from the house system, plan and budget for that from the start.

Planning Permission

In England, a conservatory falls under permitted development (PD) provided:

  • It does not extend beyond the rear wall of the original house by more than 3 m (terraced or semi-detached) or 4 m (detached), and it is no more than 4 m high.1
  • It does not extend beyond the front (principal) elevation of the original house, or beyond a side wall that fronts a highway.1
  • Together with other buildings, but not counting the original house, it would not cover more than half the land around the house.1
  • It is no higher than the highest part of the existing house’s roof.1
  • If it is within 2 m of a boundary, its eaves are no higher than 3 m.1
  • In a conservation area, National Park or other article 2(3) land, a side extension or cladding is not permitted development, though a single-storey rear conservatory within these limits can be.1

Larger Home Extension Scheme allows up to 6 m (semi/terrace) or 8 m (detached) with a neighbour consultation and the local authority’s prior approval. It is not available on article 2(3) land or on a site of special scientific interest.1

Building Regulations

A conservatory is exempt from Building Regulations approval in England if:

  • It is at ground level and does not exceed 30 m² in floor area.3
  • The glazing meets the safety requirements of Part K (Part N in Wales), which concern glazing in and beside doors and at low level in walls.4
  • It stays separated from the house by an external-quality wall, door or window, so it does not form part of the thermally controlled envelope.2
  • The house’s heating system is not extended into it.2

Fixed electrical installations in it must still comply with Part P.5

If you remove the separating wall to integrate the conservatory with the main house, it is treated as an extension: Building Regulations approval is required and it must meet the energy standards for extensions, which in practice usually means a solid, insulated roof and insulated walls.2

What to Watch Out For

  • Structural survey: confirm the existing house wall can carry the new structure’s loading.
  • Drainage: check existing gutters and downpipes can handle the additional roof catchment area.
  • Party Wall Act: if you will dig within 3 m of a neighbour’s building and below the level of its foundations, you must serve notice under section 6 of the Party Wall etc. Act 1996 at least one month before starting.6
  • Guarantees: reputable installers commonly offer a 10-year guarantee on the structure, and sealed glazing units usually carry a warranty of at least 5 years; get both in writing.
  • VAT: a VAT-registered installer will charge the standard 20% rate; ensure quotes state whether VAT is included.7

Getting at least three quotes from Which?-trusted or Checkatrade-verified installers is the most reliable way to arrive at a fair price for your specific project.

References (7)

Figures in this note were checked against the sources below on 30 September 2026. Superscript numbers in the text point to them. Every source the site cites, by topic.

  1. 1technicalvery strongThe National Archives (legislation.gov.uk), legislation.RN-Z0XQ8VParagraph A.1 sets the householder extension limits: buildings may not cover more than 50 per cent of the curtilage (A.1(b)); a single-storey rear extension may not extend more than 4 metres beyond the rear wall of a detached house or 3 metres for any other house, nor exceed 4 metres in height (A.1(f)), rising to 8 metres and 6 metres under the larger home extension route (A.1(g)); an extension of more than one storey may not extend more than 3 metres beyond the rear wall or be within 7 metres of the rear boundary (A.1(h)); eaves within 2 metres of a boundary may not exceed 3 metres (A.1(i)); a side extension may not exceed 4 metres in height, have more than one storey or be wider than half the width of the original house (A.1(j)). Paragraph A.2 removes cladding and side or multi-storey rear extensions on article 2(3) land such as conservation areas. A.3 requires materials of similar appearance and obscure-glazed, non-opening upper-floor side windows unless the opening part is more than 1.7 metres above the floor, and A.4 sets the neighbour consultation (prior approval) procedure with its 42-day determination period.
  2. 2technicalvery strongMinistry of Housing, Communities and Local Government.RN-L0FCJXThe in-force U-value tables a DIY insulation or door note must quote, with the exact numbers. Table 4.2, limiting U-values for new fabric elements in existing dwellings, sets roof 0.15, wall 0.18, floor 0.18, swimming pool basin 0.25, window 1.4 or Window Energy Rating Band B minimum, rooflight 2.2, doors with more than 60 per cent of the internal face glazed 1.4 or Doorset Energy Rating Band C minimum, and other doors 1.4 or Doorset Energy Rating Band B minimum. Table 4.3, for existing elements, gives a roof threshold of 0.35 and an improved value of 0.16, which is the figure a loft insulation note needs: paragraph 4.12 says a retained element whose U-value is higher than the column (a) threshold, for example through a loft or garage conversion, should be upgraded to the column (b) value. Paragraph 4.13 allows a lesser upgrade only where the improved value is not technically or functionally feasible or would not achieve a simple payback of 15 years or less. Paragraph 4.8 requires a replacement element to be no worse than the one it replaces as well as meeting Table 4.2. Paragraph 4.10 gives the heritage exception: where character must be maintained, a centre pane U-value of no more than 1.2 or low-emissivity secondary glazing. Note 9 records that the timber window concession of 1.6 or Band C ended on 14 June 2023. The 2021 edition came into force on 15 June 2022; a 2026 edition exists at https://assets.publishing.service.gov.uk/media/69c122a6cfa346b9d4704a55/ADL1_2026.pdf.
  3. 3technicalvery strongThe National Archives (legislation.gov.uk), legislation.RN-Y7MVZKClass 7 is the conservatory and porch exemption every extension note leans on: the erection at ground level of an extension consisting of a conservatory, porch, covered yard or covered way, or a carport open on at least two sides, is exempt from the building regulations where the floor area does not exceed 30 square metres. Where a conservatory or porch is wholly or partly glazed, the glazing must still satisfy Part K4 and K5.1 to K5.4 and Part N of Schedule 1. Class 6 exempts small detached buildings up to 30 square metres single storey and up to 15 square metres otherwise, which is the garden room threshold.
  4. 4technicalvery strongMinistry of Housing, Communities and Local Government.RN-XH6E39The standard that decides whether a loft ladder is legal and when a raised deck needs a balustrade. Published 3 January 2013, it covers protection from falling, collision and impact including stairs, ladders, ramps, guarding and vehicle barriers. Paragraph 1.31 states that retractable ladders must not be used as a means of escape. Paragraph 1.32 permits a fixed ladder, with fixed handrails on both sides, only for access in a loft conversion containing one habitable room, and only where there is not enough space without altering the existing space for a compliant stair, which is the rule that catches most loft ladder installations. Paragraph 1.29 restricts alternating tread stairs to loft conversions. For a private stair the maximum pitch is 42 degrees (Table 1.1 note 1), the normal relationship between rise and going is twice the rise plus the going between 550mm and 700mm, and for dwellings external tapered steps forming part of the building need a going of at least 280mm. Paragraph 3.1 requires guarding wherever it is reasonably necessary for safety at the edge of a floor, gallery, balcony, roof, light well, basement or similar sunken area. Paragraph 3.2 requires guarding to be at least the height in Diagram 3.1, allows any wall, parapet or balustrade to serve as guarding, and requires it to resist the loads in BS EN 1991-1-1 with its UK National Annex and PD 6688-1-1, with BS 6180 for barrier and infill panel design. Handrails should be positioned 900mm to 1000mm from the pitch line or floor.
  5. 5technicalvery strongMinistry of Housing, Communities and Local Government.RN-JYJ3I5The document that decides what electrical work a homeowner may legally do themselves, and the exact list of notifiable jobs. Regulation 12(6A), reproduced at paragraph 2.5, makes only three things notifiable: the installation of a new circuit, the replacement of a consumer unit, and any addition or alteration to existing circuits in a special location. Regulation 12(9) defines special location as, in a room containing a bath or shower, the zone extending vertically from finished floor level to 2.25 metres (or the shower head position if higher) and horizontally 600mm from the edge of the bath tub or shower tray. Paragraph 2.7 states that all other electrical installation work is not notifiable, namely additions and alterations to existing installations outside special locations, and replacements, repairs and maintenance anywhere. Paragraph 2.8 gives worked examples: a built-in cooker is not notifiable unless a new cooker circuit is needed, and connecting an electric gate or garage door to an existing isolator is not notifiable but running a new circuit from the consumer unit to that isolator is. Paragraph 2.2 confirms Part P reaches outdoor work including fixed garden lighting, pond pumps and outbuildings such as sheds, detached garages and domestic greenhouses. Notifiable work must be certified by self-certification by a registered competent person, third-party certification, or a building control body (paragraph 3.1), with the compliance certificate issued within 30 days (paragraph 3.4). Note that Approved Document P is a source of guidance rather than a ban: non-notifiable work still has to comply with BS 7671.
  6. 6technicalvery strongThe National Archives (legislation.gov.uk), legislation.RN-QBUTY2The exact wording of the two excavation triggers that decide whether a basement or a deep foundation needs a party wall notice, worth quoting rather than paraphrasing. Section 6(1) applies where the building owner proposes to excavate, or excavate for and erect a building or structure, within a distance of 3 metres measured horizontally from any part of a building or structure of an adjoining owner, and the excavation will within those 3 metres extend to a lower level than the level of the bottom of the neighbour's foundations. Section 6(2) applies within 6 metres measured horizontally where the work will within those 6 metres meet a plane drawn downwards in the direction of the excavation at an angle of 45 degrees to the horizontal. Section 6(5) requires the building owner to serve notice on the adjoining owner at least one month before beginning to excavate. Section 6(7) provides that if the adjoining owner does not serve a notice indicating consent within 14 days, they are deemed to have dissented and a dispute has arisen, which is what triggers the surveyor and award process.
  7. 7technicalvery strongHM Revenue & Customs (GOV.UK), guidance.RN-4W7T33Sets the three UK VAT rates: standard 20% on most goods and services, reduced 5% on some goods and services such as children's car seats and home energy, and zero 0% on zero-rated goods such as most food and children's clothes. The standard rate rose to 20% on 4 January 2011 from 17.5%. Some supplies are exempt rather than rated, including postage stamps and financial and property transactions. This is the reference for converting a merchant's ex-VAT trade quote into the figure a homeowner actually pays.

  1. The Town and Country Planning (General Permitted Development) (England) Order 2015, Schedule 2, Part 1, Class A, UK Government, accessed 29 September 2026. legislation.gov.uk

  2. Approved Document L, Conservation of fuel and power, Volume 1: Dwellings, 2021 edition incorporating 2023 amendments, HM Government, accessed 29 September 2026. assets.publishing.service.gov.uk

  3. The Building Regulations 2010, Schedule 2: Exempt buildings and work, UK Government, accessed 29 September 2026. legislation.gov.uk

  4. Approved Document K, Protection from falling, collision and impact, 2013 edition, Ministry of Housing, Communities and Local Government, accessed 14 September 2026. assets.publishing.service.gov.uk

  5. Approved Document P, Electrical safety: Dwellings, 2013 edition incorporating 2010 and 2013 amendments, Ministry of Housing, Communities and Local Government, accessed 14 September 2026. assets.publishing.service.gov.uk

  6. Party Wall etc. Act 1996, section 6, legislation.gov.uk, accessed 30 September 2026. legislation.gov.uk

  7. VAT rates, HM Revenue & Customs (GOV.UK), accessed 30 September 2026. gov.uk