Orangeries have become increasingly popular in recent years, a wide range of companies now construct them, using a variety of materials and approaches.
At the lower end of the market, several conservatory roof manufacturers have developed pre-fabricated uPVC orangery roof systems that are designed to be quick, easy and cheap to fit, but are little more than a conservatory roof with some plastic fascia. Whilst they clearly have their place, they are lacking in authenticity, substance and taste. These systems are generally designed to be exempt from building regulations, are restricted to standard sizes and are unlikely to add much value to the property.
Our orangeries are built to the same construction standards as a traditional extension, but allow in a greater amount of light and are more aesthetically pleasing. Costs vary, but they will generally add more value than an traditional extension as the orangery and adjoining rooms will benefit from greater levels of natural light.
In most cases, orangery foundations will need to be approved by a local authority building inspector.
Currently building regulations exceed past building standards, therefore it is not uncommon for us to put in deeper foundations than those on the existing building, particularly where there is clay in the ground and trees are nearby.
Orangery Piled Foundations
In some instances, piles are the most economical solution. Due to the increasing number of instances where this proved to be the case, we have invested in some mini-piling equipment. This is ideal in restricted access situations and/or where very deep excavations are required.
Orangery Structural Integrity
Whilst masonry is capable of bearing enormous downward loads, narrow piers and sections of brickwork generally do not possess much lateral strength. However, it is often desirable from a design point of view to incorporate narrow masonry piers to increase the proportion of glass. Where required, we use a steel portal frame to strengthen the brickwork and the overall building.
In most cases, it is important to ensure the conservatory or orangery seamlessly blends in with the existing building. Matching the masonry is an obvious, but often overlooked, way of doing this.
Boring it may sound, but brick libraries do exist! We have a number of connections with brick merchants and brick matchers to ensure we get the best available bricks for the job. In addition to matching the main brick, we would normally match any feature or detail bricks.
Where appropriate we will use reclaimed bricks, from Yellow, Red or Multi Stocks, to Plain or Multi Gualts, and Arlesey Whites. These are sourced form a variety of local stockists as local buildings tend to be built from local bricks. Unfortunately battered old second hand bricks cost a lot more than brand new ones, but the end result always justifies the cost difference.
Brickwork and Pointing
Matching the bricks is only part of the job, they also need to be laid and pointed appropriately. For modern houses this is a Stretcher Bond, bricks laid lengthways with a cavity wall.
On older properties a Flemish Bond was often used, bricks laid in alternate directions so that the inner an outer leaves of brickwork were bonded together. This is not appropriate form modern cavity walls, but using “snapped headers” can replicate this effect whilst providing the insulation and damp-proofing properties of a modern cavity wall.
Cavity Wall Insulation
Insulation is fitted in both the floor and walls. The exact specification will vary between jobs; but typically there is 100mm of Isowool type insulation the cavity walls.
For the inner leave, thermal blocks are used which when combined with the insulation and plaster give an overall u-value of around 0.27 W/m 2K
Either a concrete floor slab is laid or a suspended concrete “beam and block” floor is used. A concrete slab is laid on compacted and blinded hardcore, with a damp-proof membrane. The top of this will typically be 170mm below the finished floor level, the difference is made up with insulation and screed to allow both new and old floor levels to match.
Using a screed on top of insulation allows us to fine-tune the final floor level to perfectly match the existing, essential when new opening to the house are being created and desirable in most other cases. It also make it convenient to bury cables and pipework, either to provide services into the conservatory, and/or as underfloor-heating.
The downside of a screed is that is need to dry out before a final floor covering can be laid. We normally aim to get the screed down as soon as possible, then work on finishing other aspects of the build whilst the screed dries out.
Orangery Roof Construction
Orangery roofs are essentially big flat roof with a hole in the middle for the glazed lantern. This sounds simple, but they are one of the more complex types of roof to construct. There are alternative methods as described here but we’ve found the flat roof system to be the best.
To form the structural opening, we generally use Glulam beams. These are lighter and better insulated than steel, allowing us to span over ten metres.
Orangery Roof Covering
We typically use Sarnafil to cover the flat roof area of our orangeries. More details on Sarnafil.
The roof is laid to slight falls, which are typically hidden behind a decorative fascia or brick parapet. Rainwater outlets are strategically positioned and whilst they are normally 100mm (4″) in diameter and easily accessed, we usually supply leaf guards to prevent blockage.
The flat roof area can can be walked on, which makes maintenance of the existing property far more practical than with other options.