How Much Does a Conservatory Cost to Build?

It costs around $30,000 to build a conservatory, but most conservatory installations run between $10,000 to $80,000 (or about $200 to $400 per square foot). You can save money with a modular kit for a detached garden room, ranging from $7,000 to $25,000. 

Conservatories have a rich history. These glass enclosures function as an additional living space where you can grow plants or spend time. Think of it as a livable greenhouse that’s attached to your home.

Conservatory Cost Factors

There’s a reason conservatory prices have a wide range. You can add to an existing space or build an entirely new room. The latter is typically more expensive. The size, type of materials, and design will also greatly impact the total cost. 

Size

Conservatories cost an average of $200 to $400 per square foot, including professional installation. In other words, the bigger your conservatory, the more you’ll spend. A small conservatory measures 10 by 10 feet and costs as little as $10,000. 

A large extension of your living space at 20 by 30 feet can cost more than $80,000. Many homeowners split the difference and build a 10-by-15-foot garden room for $25,000 to $45,000. Here are some typical costs.

New Conservatory vs. Garden Room Extension

The cost to build a conservatory from scratch is similar to the cost of a home addition, but you can save money by building onto an existing space. The cost to build a covered patio can be as low as $3,000. You can also convert a greenhouse into a livable conservatory. All you have to do is add insulation and climate control, which will cost anywhere from $5,000 to $20,000.

Glass Roof vs. Tiled

Most garden rooms have glass roofs, which range between $6,000 and $12,000 to install. You can lower the price by opting for tile instead. Adding a tile roof costs between $3,000 and $8,000. Keep in mind that a glass roof is essential for growing plants and will make the space a true extension of the outdoors. Conservatories typically get more sun than a sunroom because of the roof.

Frame Material

Choosing the right frame material is important for both style and structural integrity. The material you choose also significantly impacts your budget. Wood is the least expensive, while a frameless conservatory is the most expensive.

Land Prep and Foundations

Since conservatories are essentially home additions, the land has to be level before construction can start and you’ll need to install a concrete foundation. Expect to spend:

• $1,300 to $5,300 on the cost of clearing land

• $5 to $37 per square foot on the cost to install a foundation

• $0.90 to $2.00 per square foot for underfloor insulation

• $3 to $22 per square foot on flooring installation costs

Regulations and Building Permits

Most living space additions require local authorities’ permission. Most building permits cost $150 to $2,000, but it depends on the project. Talk to your contractor about regulations and necessary steps before starting the project. You may also need to check with your homeowner’s association if you have one.

Windows and Vents

Ventilation is a necessary part of home conservatory costs. You need it to grow healthy plants. Moisture trapped in roots can cause root rot and kill your plants over time. On top of that, all the windows in a conservatory can make the room quite hot in warm weather if you don’t have some sort of climate control. Ventilation helps mitigate these issues.

Windows are one way to increase ventilation. Adding operable windows that you can open and close increases the cost. Expect to spend $300 to $1,200 each. 

Vents also help increase ventilation in your conservatory. The cost to install roof ventilation is typically $2 to $3 per foot, excluding labor. Manual vents, which are on the low end of the price spectrum, are adequate for small conservatories with only one or two vents to open close. 

Electronic (or automatic) roof vents, which cost about $1,500 each, are better for large conservatories. Rather than use a pole to open and close vents, you’ll be able to open all the vents with a button. Some even have climate control and rain sensors.

Average Conservatory Prices by Design and Type

The broad category of conservatories (or garden rooms) includes several styles, whether you want to use your space as a garden office, sunroom, or traditional orangery. Each design has its advantages, disadvantages, and budget considerations.

Mediterranean/Lean-To

For $15,000 to $35,000 you can get a simple, straightforward design that prioritizes natural light. Mediterranean or lean-to conservatories feature a sloped roof and are the simplest to install as an addition to an existing room.

Victorian

A Victorian-style conservatory costs $15,000 to $60,000. This design follows a classic style that often features multiple softer angles instead of a typical rectangle. French doors are typical for this style, though expect to increase your budget to accommodate French door costs. This option tends to be white, with PVC as the main building material.

Natural

A more rustic look uses wooden materials and costs between $10,000 and $50,000. This option is especially popular for homeowners who build the space specifically to connect with nature. Interior design complements the natural look, with wooden floors and rustic decor.

Gable

Especially popular for freestanding structures, gable designs range between $20,000 and $60,000. Intricate windows and other decorative finishes help you make a statement beyond adding function. Because of the intricacy, your window installation budget will be on the higher end of the typical range.

Modern

Modern styles range from $10,000 to $70,000. They include anything from Mediterranean to frameless. Clean, symmetrical styles dominate. PVC and aluminum are most prevalent if you choose to frame the room.

Orangery

The cost to build an orangery is $40,000 to $80,000. This is the most expensive type of garden room. It's modeled after conservatories in the 17th and 18th centuries, when upper-class citizens built expensive structures to grow tropical fruits.

Especially in colder climates, the purpose of orangeries was to grow and protect citrus trees from frost. Today, the same type of building acts as a high-level addition to your home. The most common framing material is brick, but you can also use an oak frame for a budget-friendly option.

Benefits of a Conservatory

A conservatory can add around 6% to the value of your home, but that’s not the only benefit. The main draw is that a new conservatory essentially adds an extra room to your space. It’s a less expensive alternative to a full-on extension, but gives the same benefits. For those with a green thumb, it’s the perfect place to grow an indoor garden year-round. It also offers a calming ambiance and allows you to experience the outdoors without experiencing the elements.

DIY vs. Hiring a Conservatory Builder

Technically, you can build a conservatory on your own, but the process is more straight forward if you choose a modular kit. Regardless, this job is complex and involves foundation work, landscaping, building, roofing, and electrical skills. In most cases, you should hire a pro to build your conservatory.

A DIY project saves on budget, but it can invite potential problems down the road. The foundation might sag. You might compromise the structural integrity of the space—or even your home since the structures are attached. Mistakes in the building process increase future repair costs. Get the job done right by hiring a conservatory and sunroom contractor near you.

FAQs

What's the difference between a garden room, conservatory, and greenhouse?

A conservatory is a glass enclosure that acts as an extension of your home. Though similar, greenhouses are stand-alone structures. As a result, the cost of a greenhouse is typically significantly less. 

Garden rooms are a little different. A conservatory can function as a garden room, but you can also have detached garden rooms. The main distinction is use. These light-filled structures enable plant growth but typically have a cozier style compared to a utilitarian greenhouse. Orangeries are the classic type of garden room.

What is the difference between a conservatory and sunroom or solarium?

A four-season sunroom costs between $20,000 and $80,000. Sunroom is commonly used as a catch-all term, but typically refers to the type of shade-filled enclosure common in the United States. Oftentimes, a sunroom will feature a tile roof and only some windows. 

A solarium, which costs between $30,000 and $75,000, is made almost completely out of glass—including the roof.  The term solarium is often used interchangeably with conservatory, though conservatories usually refer to a traditionally British or European style of architecture.

What is a garden office, and how much does it cost to build one?

A garden office ranges between $10,000 and $40,000 in most cases. Think of it as a mix between sunroom and home office. Garden offices are often glass-encased. They are comfortable workspaces but separate from your living area.

Garden offices can be conservatories that connect to your home or separate outbuildings with their own heating and insulation. Your budget should account for materials, construction, insulation, and electrical work.

How much does a glass roof cost per square foot?

Expect to pay between $15 and $60 per square foot for your glass roof. That price includes the glass itself, as well as installation. Where you fall on that range depends on the quality of glass, type of frame, and more.

What's the cheapest way to get a conservatory built?

The easiest option is to buy a modular kit for as little as $7,000. However, it comes with a few disadvantages. The insulation might not be effective. It also must be freestanding and cannot be an addition to your existing space.