While they might not be a common sight, two-storey conservatories are definitely striking features, adding instant 'wow', not to mention creating some beautiful, light-filled spaces internally.
Conservatory ideas have come a long way since the 1980s, when they picked up their reputation as flimsy add-ons prone to leaking, overheating and for being too cold to spend time in during the winter months. These days, largely thanks to advances in glazing technology, they can be designed to provide a beautiful sunny spot from which to sit and enjoy the garden, protected from the elements, all year round.
But can they really span more than one storey? Is it a good idea to even try to add a two-storey conservatory to a house, and just what does the job entail? We put it to the experts.
Article continues belowCan you have a two-storey conservatory?
If you are adding a conservatory to increase the floor space within your home, it makes sense to consider ways of maximising this new structure, and building another storey would certainly do this – but is it viable?
"Two-storey conservatories are a fairly specialist project and they need careful planning from the outset," picks up Michael Arrowsmith, manager at Etheridge Windows. "They’re also quite uncommon, it’s not something we’re often asked about compared to standard conservatories or single storey extensions.
"Structurally, they’re much closer to a small house extension than a typical conservatory," continues Michael. "You’re effectively adding two levels of glazed space onto the rear of a property, so the foundations, structural supports and how the new structure ties into the existing house all need proper design work. In most cases there will be steelwork involved and a structural engineer will usually be part of the process."
Michael is manager at Etheridge Windows, a family-run business established in 2019. They specialise in doors, windows and conservatories and aim to make the whole process of choosing new windows and doors stress-free.
What is a two-storey conservatory?
Unlike standard conservatories, two-storey designs are rather complex. More thought needs to go into every aspect, including their foundations and how that second storey will be supported.
"From a design point of view, the biggest consideration is how the upper floor connects with the house," says Michael Arrowsmith. "Some homeowners use the space as part of a bedroom or landing area, while others create a balcony overlooking the conservatory below. Either way, it needs to feel like part of the original building rather than an add-on."
Often, these two storey structures are more akin to either orangeries, which feature more solid elements than conservatories, or complex glass box extensions.
"In one project we completed (seen below), the lower basement floor was completely excavated and extended to create a bright, functional space that previously had no garden access and now opens to a lower courtyard," explains George Lucas, marketing executive at Vale Garden Houses. "The upper level orangery provides light-filled views over the garden. This design approach created large amounts of usable space across two levels and allows light to flood into both levels of the home. It also transformed how the home is used, creating a seamless connection between indoors and outdoors from both levels while enhancing functionality and aesthetics of the rear elevation."
George Lucas is the marketing executive at Vale Garden Houses. He brings a wealth of knowledge and experience regarding conservatories that contributes to all areas of the company.
Are two-storey conservatories a good idea?
If a two-storey conservatory is something you have been considering, you may well be debating whether or not an extension or a conservatory will be the best option for you. So what can a dual-height conservatory offer?
"The main advantage is the amount of space and light you gain," says Michael Arrowsmith. "You’re creating a tall glazed area that can transform the back of a property and bring a lot more daylight into both levels of the home. For homeowners who want something visually striking, it can make a big impact."
"One advantage of a split level conservatory extension is the increased living space you get without expanding further into the garden – something particularly valuable in townhouses or homes where outside space is limited," adds George Lucas.
What are the disadvantages of a two-storey conservatory?
Given that this type of structure is going to take time to design and build, cost you a fair amount of money, and will have a huge effect on the appearance of your home, you need to go into the project fully aware of the downsides of a two-storey glass addition such as this.
"There are a few drawbacks to be aware of. Cost is always going to be the main one, as you’re dealing with a much larger structure and more complex build than a standard conservatory," points out Michael Arrowsmith. "Thermal performance also needs careful thought. Modern glazing and roof systems can deal with this well, but it needs to be specified properly at the design stage."
Along with the need to fully address the potential this kind of building will have for overheating, you will also need to look at other common conservatory pitfalls, such as poor privacy measures and inadequate ventilation. And don't forget, all that extra glass is going to need regular cleaning if you want this to be an attractive addition to your home.
Are two-storey conservatories expensive?
Any kind of heavily-glazed structure, be that an extension or orangery, need to be meticulously designed and specified if you want them to be beneficial additions that will stand the test of time – and this kind of project doesn't come cheap. While conservatory costs tend to be amongst the most affordable when compared to other kind of extensions, when you start adding another level, prices start to rise.
"In terms of costs, a two-storey conservatory will usually start somewhere around £35,000 - £50,000 and can go well beyond that depending on size, materials and structural work required," reveals Michael Arrowsmith. "If significant alterations to the house are needed, that price can rise very quickly."
Given that it is possible to add a simple, small uPVC lean-to conservatory for as little as £12,000, you can see that there is a big difference.
FAQs
Do you need planning permission for a two-storey conservatory?
Part of the beauty of standard conservatories is that they rarely require planning permission, providing they meet permitted development criteria. In the case of two-storey structures, however, things are likely to be very different.
"Unlike most single-storey conservatories, two-storey designs almost always require planning approval because of their height and visual impact," explains Michael Arrowsmith. "That doesn’t mean they’re difficult to get approved, but the design needs to sit comfortably with the property and the surrounding homes.
"Good drawings and early discussions with the local authority tend to make the process much smoother."
Even where your conservatory won't require planning permission, conservatory building regulations will always be a requirement. Not only will they ensure the structure is safe to spend time in, but adhering to them will also mean your new addition is energy efficient.
