What Does an Aluminium Winter Garden Conservatory Cost?
Updated: Oct 9
An aluminium winter garden conservatory costs £2,500 to £3,500 per square metre for the glazed structure, before the building works that sit beneath and around it. A simple roof-and-frame design sits at the lower end; a fully glazed room with large sliding doors, automatic vents and external awnings sits at the top. Add the base, the walls, the services and the finishes, and the whole project for a typical family-sized room is a substantial investment, comparable with a high-quality hardwood conservatory of the same size.
What drives the cost of an aluminium conservatory
The price of a winter garden is decided in four areas, and a quotation that only covers the first of them is not a quotation for the room.
The glazed structure
The aluminium frames, the glazed roof, the sliding or bifolding doors and the glass itself. Four things move this figure: the size of the room, the style and detailing, the number of opening elements, and any special glass such as triple glazing, solar control or self-cleaning coatings. This is the part priced at £2,500 to £3,500 per square metre.
Construction works
The insulated base and damp-proof membrane, foundations, blockwork and brickwork for any flank walls, the openings cut into the house, plastering the external wall that is now inside, lead flashings, electrics, lighting, underfloor heating, screed and the connection of rainwater drainage. Taken together these run to approximately £750 to £1,000 per square metre.
Final finishes
Skirting, architrave and second-fix carpentry, decoration, and the floor. For a painted finish to the internal walls and a tiled floor, allow £120 to £150 per square metre. Stone floors, bespoke joinery and lighting design sit above that.
Professional fees and applications
A householder planning application in England has a national fee of £528 (from April 2025), with the drawings and documents on top; a complex listed building application can exceed £2,000 in drawings and heritage reports, though listed building consent itself has no fee. A building regulations notice is about £300 and a full plans application over £1,500. Structural calculations, for a steel beam over a new opening for example, are about £300 each.
What a winter garden costs in practice
Put the four parts together and the shape of the budget is clear. The structure is the largest single line, the construction works are the one most often underestimated, and the fees are small but not optional. For comparison, a hardwood orangery of similar size sits at £2,500 to £5,000 per square metre for the build, so the two are closer in cost than their appearance suggests; the full picture for the traditional option is in our guide to orangery extension cost.
To turn the rates into a budget for your room, work through it in order:
Floor area x £2,500 to £3,500 for the glazed structure. A 4m x 4m room is 16 square metres; a 5m x 4m room is 20.
Floor area x £750 to £1,000 for the construction works.
Floor area x £120 to £150 for basic finishes, more for stone floors or bespoke joinery.
Add the fees for drawings, applications and structural calculations.
Add VAT at 20%, then a contingency of 10 to 15% for what the ground and the existing house reveal.
The lower end of each range fits a simple lean-to room with a few opening doors; the upper end a room with a hipped roof, wide sliding doors, automatic vents and awnings.
Every figure above excludes VAT, which is charged at 20% on the build.
How does a winter garden compare with other ways to add a room?
Winter garden: £2,500 to £3,500 per square metre for the glazed structure, plus the construction works and finishes. The most glass and the most light, with a slim aluminium frame.
Hardwood orangery: £2,500 to £5,000 per square metre for the build. A solid roof perimeter with a lantern, and a traditional look.
Standard conservatory: usually less per square metre than either, with thicker frames, a lighter base and a roof that is harder to keep comfortable year-round.
Brick extension: can cost less at the budget end and similar at the premium end, with more wall and less light.
What does a winter garden cost to run?
Running cost depends on the glass, the orientation and how the room is heated. A winter garden with insulated, low-emissivity glazing, underfloor heating on its own controls and external shading in summer behaves like a well-glazed room of the house rather than a conservatory that swings from cold to hot. The biggest savings come from design: letting low winter sun in, shading the glass before it overheats and venting hot air at the ridge, rather than heating and cooling against the building.
Design choices that change the price
Size. A larger winter garden costs more in total but less per square metre, because the structure and the groundworks both carry fixed costs. Very large spans, over a swimming pool for instance, reverse that by needing structural steel.
Position. A room that sits in a corner has two open sides instead of three, and costs less for it.
Roof shape. A lean-to mono-pitch or reverse-pitch roof is the least costly. Hips, valleys and gables can double the cost of the roof.
Openings. Every sliding or bifolding door costs more than a fixed panel of the same size. Decide which elevations need to open and which only need to be glass.
Glass specification. Triple glazing, solar-control coatings and self-cleaning glass each add to the unit cost and each earns its place in the right position.
Automation. Roof vents, external awnings and weather sensors add to the structure cost and are the difference between a room that is pleasant in July and one that is not.
Keeping the room cool in summer and warm in winter
Design the room to work with the sun: orientation that lets low winter sun in, external awnings that shade the glass on the hottest days, and roof vents that release hot air. That is how our winter garden conservatories are designed, and our guide to what a winter garden conservatory is explains the type.
How to budget for an aluminium conservatory
Start with the use, not the size. A room that will become the kitchen or the main living space justifies a different budget from a garden room used at weekends. Then fix the size and position from the house and the garden, decide which elevations open, and let the glass specification follow the orientation. Ask for the four parts of the cost separately, so the structure, the construction, the finishes and the fees can each be checked and adjusted. A budget built that way rarely surprises anyone at the end.
Aluminium conservatory cost questions, answered
How much does an aluminium conservatory cost per square metre?
£2,500 to £3,500 per square metre for the glazed structure, plus approximately £750 to £1,000 per square metre for the construction works and £120 to £150 per square metre for basic finishes, all before VAT.
Is an aluminium winter garden cheaper than a hardwood orangery?
They are similar. Both provide the same structural stability, weather and thermal performance; the difference is the look. A hardwood orangery runs £2,500 to £5,000 per square metre for the build, against £2,500 to £3,500 for the glazed structure of a winter garden.
Do I need planning permission for a winter garden?
Often not, if it stays within the permitted development limits for a single-storey rear extension. Where an application is needed in England, the householder fee is £528 and the drawings are extra. Our guide to permitted development and planning permission for glass extensions covers the limits.
Talk to our design team
If you would like the four parts priced for your house rather than estimated, talk to us about your project and we will size the room, work out the cost and adjust the design with you before anything is drawn in detail.
