You’ve decided you want more light-filled space at the back of the house. Everyone keeps using the words orangery and conservatory as though they mean the same thing, and the quotes you’re getting range from £12,000 to £80,000 for what sounds like a similar sized room. Understanding what actually separates the two will save you from comparing quotes that aren’t comparing like for like.

Most homeowners assume orangery is just a fancier word for a posh conservatory. It isn’t. The two are genuinely different structures, built differently, performing differently, and costing differently, and choosing the wrong one for what you actually want to use the space for is one of the more expensive mistakes people make with home extensions.

Based on current 2026 UK build costs, building regulations, and our experience from hundreds of extension projects across Mansfield, Nottinghamshire, South Yorkshire, and Derbyshire, here’s exactly what separates an orangery from a conservatory and how to work out which one is right for your home.

Key Topics Covered

  • The genuine structural differences between an orangery and a conservatory
  • Why an orangery costs roughly twice as much per square metre
  • Energy efficiency and year-round usability compared
  • Planning permission and building regulations for each
  • Which one adds more value to your property
  • How to decide which is right for your specific needs

The Basic Difference

A conservatory is a predominantly glazed structure, typically with a glass or polycarbonate roof and thin frames, designed to feel like an extension of the garden brought indoors. Somewhere between 60 and 80% of a conservatory’s external surface is glass.

An orangery is closer to a genuine extension with generous glazing rather than a glass room with some walls. It has solid masonry walls, usually brick to match the existing house, a flat or shallow-pitched roof with a central glazed lantern rather than a fully glazed roof, and it is built with proper insulated foundations designed to the same standard as the rest of your house.

The distinction dates back to the 17th and 18th centuries, when orangeries were literally used to grow citrus trees through the winter and needed solid, heat-retaining walls with enough glazing to let light in without losing all the warmth. Conservatories evolved later as lighter, fully glazed Victorian additions built primarily to let light flood in. That history still shapes how each structure performs today.

What This Means for How the Space Actually Performs

This is where the difference stops being aesthetic and starts affecting how you actually live in the room.

An orangery with a solid insulated roof typically achieves a U-value of around 0.18 to 0.25 W/m²K, which meets current Building Regulations for a habitable room. A conservatory with a glazed roof, even double glazed, typically only achieves a U-value of around 1.2 to 2.0 W/m²K, meaning it loses heat five to ten times faster. Wall performance follows the same pattern, with an orangery’s solid insulated walls performing many times better than a conservatory’s glazed panels.

The practical result is that a conservatory typically costs somewhere in the region of £300 to £600 more per year to heat than an equivalent sized orangery, and that gap shows up immediately the first winter you try to use the space as anything more than a summer sitting room. Most homeowners who build a conservatory as their only living space extension end up using it for six or seven months of the year and abandoning it through the coldest stretch of winter and often through the height of summer too, when a fully glazed roof turns the room into a greenhouse.

An orangery, built and insulated to the same standard as the rest of the house, is genuinely usable all year round. That is the entire point of paying more for one.

The Cost Difference

Costs for both structures vary considerably depending on size, specification, and who you use, but the pattern across current 2026 pricing data is consistent.

A conservatory typically costs £1,200 to £2,000 per square metre, putting a standard 3m x 3m conservatory at roughly £10,800 to £18,000, and a larger 4m x 5m structure at £24,000 to £40,000.

An orangery typically costs £2,000 to £3,000 per square metre, sometimes higher for premium aluminium frames and bi-fold doors. A 15 to 16m² orangery generally lands somewhere between £30,000 and £52,000, and larger or higher specification orangeries can run considerably beyond that.

Some industry sources put the gap even more precisely, with orangeries running 50% or more above conservatory costs on a like-for-like footprint, driven by the solid insulated roof, brick walls, and more substantial foundations an orangery requires.

Whichever figures you’re quoted, the underlying reason for the price gap is the same. An orangery is built to full extension standard with proper foundations, brickwork, and insulation. A conservatory is a lighter, factory-produced structure with a simpler build process, which is exactly why it costs less and performs less well thermally.

Planning Permission and Building Regulations

Here’s something that catches a lot of homeowners out. Calling a structure an orangery rather than a conservatory does not change the planning rules that apply to it. What matters to your local planning authority is the size, height, and position of the structure, not the label you put on it.

Most conservatories fall under permitted development and don’t need planning permission, provided they meet size and coverage limits. For a typical semi-detached house, that generally means a rear projection of up to 3 metres, or 4 metres for a detached property, single storey, not taller than the existing eaves, and not covering more than half the garden. Listed buildings, conservation areas, and areas of outstanding natural beauty always require planning permission regardless of size.

Orangeries more often exceed permitted development limits simply because they tend to be built larger and as more substantial additions, which means full planning permission is required more frequently, typically at a current application fee of a few hundred pounds. It is entirely possible to build a small orangery within permitted development limits, and equally possible to need planning permission for a large conservatory. The structure’s name has no bearing on this at all.

Building regulations are where the two genuinely diverge. A conservatory can often be exempt from full building regulations approval if it is thermally separated from the main house by proper external doors, has an independent or no heating system, and is under 30m² in floor area. That exemption is precisely why so many conservatories perform poorly as year-round living space. They are deliberately built to a lower standard because building regs doesn’t require otherwise.

An orangery, because it is built with solid walls and generally opened up into the main house through wide archways or without a separating wall at all, is almost always treated as a full extension of the heated living space and must comply fully with current building regulations, including the same insulation, glazing, and energy performance standards as a brick extension. If your design opens the new room directly into your kitchen or living room without a separating door, building control will require it to be built and insulated to full standard, whatever you choose to call it.

Which One Adds More Value to Your Home

Neither structure reliably returns its full build cost when you sell, which is true of almost every home improvement, but the two perform differently.

An orangery tends to add more value proportionally because it functions as genuine, comfortable living space that a buyer can use all year round without hesitation. It reads to a buyer as a proper extension rather than an add-on room.

A conservatory is viewed more cautiously by buyers. Because so many conservatories are cold in winter and unbearably hot in summer, buyers often mentally discount the space rather than adding its full cost to their valuation, and a dated or poorly built conservatory can actively put buyers off rather than adding appeal. A well-built, modern conservatory with a solid or hybrid tiled roof performs considerably better than the traditional fully glazed version, closing some of that value gap.

How to Decide Which Is Right for You

If you want a bright, garden-facing room primarily for spring and summer use, somewhere to sit with a coffee on a sunny morning or host guests through the warmer months, and budget is the primary constraint, a well-specified conservatory does that job at a lower cost.

If you want genuine additional living space you’ll use every day of the year, perhaps an open-plan kitchen extension, a family room, or a space that functions as a proper part of the house rather than an occasional add-on, an orangery is very likely the better investment despite the higher upfront cost. The £300 to £600 a year saved on heating, combined with genuinely usable space in January as well as July, adds up considerably over the years you’ll live in the house.

There is also a hybrid option worth knowing about. Many companies now build what’s sometimes called an orangery-style conservatory, or a conservatory with a solid tiled roof replacing the traditional glass one. This closes much of the thermal performance gap at a lower cost than a full brick-walled orangery, and is worth discussing with your builder if budget is tight but year-round usability still matters to you.

The Rosebrick Approach

At Rosebrick Developments, we build both orangeries and conservatories across Mansfield, Nottinghamshire, South Yorkshire, and Derbyshire, and we’ll always give you an honest recommendation based on how you actually intend to use the space, not just the one that carries the bigger price tag.

If you want a room you’ll use twelve months of the year, we’ll specify and build it to full extension standard from the outset, proper foundations, cavity insulation, and glazing that meets current Part L energy regulations, so you’re not heating a room that leaks warmth through a single-glazed roof. If a lighter, more affordable garden room is genuinely what you need, we’ll build that properly too, without over-specifying something you don’t need.

We manage the planning and building regulations process for both structure types as standard, so whichever direction you go, there are no surprises about what’s required before work starts.

Ready to Add Light-Filled Space to Your Home?

Whether you’re leaning towards a classic conservatory, a full brick orangery, or something in between, across Mansfield, Nottinghamshire, South Yorkshire, or Derbyshire, getting the right structure for how you’ll actually use the room matters more than the label on the brochure.

Contact Rosebrick Developments today for honest advice on which option suits your home, your budget, and how you want to live in the space, along with a transparent quote that reflects exactly what you’re getting.