Orangeries FAQ

What is an Orangery?

I am often asked this questions or told by people what their interpretation is.

‘Even if your ultimate desire is to grow citrus trees an ORANGERY can be whatever you wish it to be and can vary from an extremely elaborate and expensive structure costing many thousands of pounds to a modest ‘full Orangery design’ with a central glazed lantern and internal perimeter ceiling having down lighters at a very realistic budget’.

Much will depend on materials to be used, overall dimensions and design.

I trust that the following ‘Questions and Answers’ will help you embarking on the journey to thoroughly research the very best design, materials and price which pleases you in all respects.

Most people have a picture in their heads of a flat roof extension to their home with a centrally positioned glazed lantern.

Most certainly not.  If you have deep pockets and a country mansion, then most certainly your ultimate project may cost many thousands of pounds.  There are however opportunities to purchase a superb Orangery design which fulfils all your needs at prices which many people are able to purchase when a high budget is not desired.

There will be no greater needs other than an appropriate foundation, depending on supporting soil stability and the percentage of solid walling within the side elevations.  Generally speaking, there should be absolutely no further requirements if you were adding a standard extension to your home.

Whilst any traditional thinkers would wish to have a low dwarf wall and small glass panels, there is a big move towards glass to ground and very large glazed panels even up to 2 metres in width.  You may however wish to have brick or stone columns but do fully consider not just outward appearance but looking from within and if these might interrupt your view of the garden and surrounding countryside.

Absolutely whatever you wish.  Hardwood, High Specification PVCu, Architectural Aluminium and in some cases GRP.  Each will of course vary in price with Hardwood being the most expensive and whereas PVCu would previously have been frowned on for use in an Orangery, the very high specification extrusions which we offer have been chosen by architects and customers demanding the very highest of standards.

Whilst Bi-folding doors often are initially considered, in the British climate you need to carefully consider whether the full advantage of these more expensive systems can be fully taken advantage of – ideal when they can but most certainly not for the majority of each year.  Outward opening hinged French Doors will provide you with a  2 metre opening and you may even wish to have two of these within your side elevations.  Windows need to be carefully considered and whatever you wish, is easily factored into your ultimate choice of design.

A single large lantern with a perimeter internal ceiling of some 900 has generally proved to be the most popular.  However for a larger structure, which may be rather long compared to its depth, two lanterns could be considered.  Most importantly, you need to be fully reassured that whoever is constructing the roof, fully complies with Current Building Regulations as your project will most certainly fall under these.  A very important issue is how the lanterns are supported and whether this is to be steel, glulam beams with perhaps double or triple joists.  Most certainly structural engineers full assessment with appropriate calculations will be required, as your project will need to be compliant with Current Building Regulation Stipulations.

The most popular is down lighters controlled by a dimmer switch within the surrounding perimeter ceiling.  Many choose to have a decorative chandelier set with the centre of their lantern.

Whilst many traditional conservatories are constructed in Hardwood and this material with a special very low maintenance Aluminium Capping has been used, the tide is now changing.  Even for Listed Buildings many local authorities will accept a High Specification Architectural Aluminium, as long as the extrusions are designed to look like timber profiles.  It should be considered that the roof is an extremely vulnerable area and if Thermally Separated Architectural Aluminium is chosen, this will give peace of mind for the foreseeable future.  Not least of all, these latest Architectural Aluminium Lanterns are designed with extremely slim profiles and large panels of glass rather than having overpowering heavy timbers.  This is extremely important as the lantern is such a predominant feature within an Orangery.

The side elevations are relatively straightforward.  It should most certainly be toughened to the very highest of specifications, Low ‘E’ for Heat Retention and Argon Gas Fill.  For the roof lantern there is much more to consider.  This should most certainly be Easi-Clean, some call it Self-Clean but not strictly true, as it most certainly will require washing with a hose or similar but very much easier than glass which was available some years ago.  Most people, unless surrounded by trees or a north elevation, would wish to have Heat Reflective Glass.  This is available in Blue, Neutral or Clear and extremely effective, protecting you in the height of the summer whilst still allowing good light to penetrate plus a degree of solar gain.

In this respect, you will most certainly have to thoroughly carry out your research.  There are single ply damproof membranes which come up to a 30 year guarantee but you need to be absolutely confident that claims by their providers and indeed who installs them, will live up to all of their claims.  Alwitra by ICB is most certainly a Rolls Royce product and usually only available to those who have undergone intensive training to provide and fit this.  Such that the manufacturers will offer an independant substantial guarantee.  You could certainly walk on this material but of course not in high heels or if there are any sharp objects may have come to lay on this, for all the obvious reasons.

If you have carefully studied my outline above, then is it is reasonable to assume that you will make all the right decisions and most certainly employ a company, appropriate materials and structural details which will allow you to do so.  A very high percentage of our customers not only employ us to construct an Orangery but also open up connecting walls to their home with the introduction of Steel RSJ’s, so that the adjacent room becomes very much part of the Orangery.  This is very different from traditional conservatories which were a glazed structure fitted on an outside elevation with a connecting door.  It is therefore extremely important that the overall thermal efficiency, not just within the structure but also beneath a new floor is of the very highest specifications.

My concluding professional advice would be to ensure that any company you may approach for an orangery quotation, can off you just not a portfolio of many different design but that these should very much include an extremely high percentage of projects actually completed by them.  NOT JUST OVER THE LAST THREE OR FOUR YEARS.  My company is often employed to carry out detailed technical reports for orangery projects and sun rooms when they have failed to live up to the customer’s expectations.  This may involve numerous sealed units breaking down, foundations which have moved, inadequate lead flashing and for older projects, timber framework which has rotted.  We have numerous photographs showing these failings.

The good news is that you do not have to ‘pay through the nose for quality’, if you carry out your research thoroughly and choose a company with, 40 years continuous and proven trading, you can obtain the very best value for money and not least of all within your desired budget.


The concept of an Orangery has changed over the years and in the beginning gained its name as a protecting glass structure where citrus fruits could be grown.  There is a very special light, bright and warm area within a glass building was appreciated and many became lavish glazed palaces on country estates, where sumptuous dining and balls could be held.  In modern times, the general perception of an Orangery is structured with a fair amount of glass in the side elevations onto which is constructed a flat roof, albeit with one or more glazed lanterns.

More expensive and traditional Orangery designs have hardwood timber framework, into which varying amounts of glass are introduced.  They can have substantial corner posts and what is generally known as decorative pillasters may be chosen.  Some structures will have brick or stone columns. Glazing should be with sealed units which are Low E & Argon Gas within.  All glass should ideally be toughened.  Within the lantern you may well wish to have Heat Reflective Glass Panels and Easi-Clean, you have a choice of bronze, blue, neutral or clear Heat Reflective panels.  If you are not a Listed Property or wish to have Hardwood, then High Specification Thermally Separated Architectural Aluminium framework or PVCu may be chosen.

This will very much depend on the sub-structure where your Orangery is to be built.  You will certainly require appropriate foundations and the more unstable soil you have will dictate what depth these need to be and you may require steel reinforcing or even piling.  Many people believe that these are dependent on the weight of the upper structure but the most significant factor is how stable the ground is onto which their Orangery will be built.  Even a small lightweight structure will suffer from serious subsidence and consequential movement if the ground is unstable.

Glass manufacturing and its composite manufacturing and specification can appear to be a very complex subject.  It most certainly should not be because the main considerations are heat retention with low emissivity double glazed units which have Argon inside, appropriately toughened for safety and not least of all within any roof panels they have an appropriate heat reflective element, which can be blue, neutral or clear.  Another more recent opportunity is Easi-Clean, not self clean as some would suggest.  They are offering, a glass which is never easy to wash off any debris or accumulation of algae without too much elbow grease.

You may choose timber albeit capped externally with Aluminium to ensure minimum maintenance in this vulnerable area.  Thermally separated Architectural Aluminium is also popular and this will have much slimmer glazing bars.

The most import elements are Low E Glazing throughout with Argon and a substantial Celotex Insulation beneath the floor, usually 100mm.  These are combined with an overall structure which is fully storm proofed, you will most certainly should be able to enjoy a comfortable evening with family and friends, any time of the year.

Planning Permission may not be required if you are constructing on the rear elevation and no deeper than 4 metres for a detached property and 3 metres if semi-detached.  The height should not exceed 4 metres above ground level.

This concerns the structural elements of your project, such as foundations, drainage, lead flashing and not least of all thermal efficiency will apply, as long as these do no predominately have a glass or translucent roof.  Structural Calculations will be required covering Building. Many people choosing an Orangery will also desire Open Plan where adjoining doors or a window is opened up from your home.  Heat Loss Calculations are then required and to achieve these you may need to have extra insulation in the loft or upgrade your boiler.

Good foundations will certainly be required, their construction and depth will depend on the stability of soil where the Orangery is being constructed.  The internal floor will generally include removal of any insecure soil compacted scalping with sand blinding.  Substantial damproof membrane onto which is constructed a concrete oversite and usually 100mm of insulation.  A sharp sand and cement smooth screed is then laid on top ready to receive tiles, Karndean Flooring or carpets.

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