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The Citrus House

The Citrus House (and Propagation House) are listed grade II as ‘a large glass house of early date retaining considerable architectural character’.

The Renovation of the Citrus House

The 200-year-old Citrus House was part of a grant package for £1.8 million under the Rural Development Plan for Wales, run by the Assembly and the European Union. 
The money was spent on several projects and the restoration of the Citrus House was one of them.
The Citrus House in Margam Park was built in around 1800 to replace earlier greenhouses on the estate.

Thanks to the grant it has been returned to its original use, which was to house citrus plants.

Understanding the Building

The building was originally referred to as the ‘Orange Wall’ rather than the Citrus House. Confirmation of the term ‘Orange Wall’ is found in the records when Lady Mary Fox Strangways asked that ‘timber in the gardens be felled to prevent interception of light onto the Orange Wall’. (Lady Mary was the wife of T. M. Talbot who built the Orangery).

From Estate records we know that the construction, supervised by William Gubbings, was at a cost of £223 9s 8½d. The records indicate that the new conservatory was built on the foundations of a former building. Each year the “lights” were removed from the ‘Orange wall’ in May and replaced in October. They also indicate that the majority of the trees growing in here were against the trellis on the back wall. Records from 1842 indicate that there were 40 such trees in the structure.

What is certain is that prior to the construction of the present Orangery there were at least three major greenhouses housing the Margam citrus collection, the greenhouses were between 100-150 ft in length. Other accounts show that Citrus and Fuchsias have been kept in this structure, the existence of apparently contemporary trellising and raised internal beds suggests that the Citrus House may have also had other uses.

The Citrus House, some 44.5m long, consists of a glazed central section (38.6m long) between cement rendered pavilions at either end each with a glazed roof. The main glazed roof is in 2 pitches supported centrally off an arcade of slender cast iron columns. The pavilions and rear wall are in rubble stone. To the front is a low level plinth in dressed free-stone. In 2007 the glasshouse fell into disrepair and deemed too dangerous for public access . With the help of a grant from The Rural Development Plan the Citrus House has now been painstakingly restored to its former glory and today welcomes us to promenade should the weather turn wet!

How significant is the Citrus House as a Building?

The Citrus House (and Propagation House) are listed grade II as ‘a large glass house of early date retaining considerable architectural character and for group value with Orangery and other structures at Margam Park.’

The buildings lie within the Registered Historic Park and with the Orangery make an enormous contribution to the architectural, social, historical and cultural significance of this nationally important site. Its importance, architecturally, lies in its composition and scale together with its iron structure and lightweight timber detailing. The slender iron columns, ‘stick’ thin rafters and scalloped glass tiles are a testament to Victorian garden architecture. Without constant maintenance these buildings deteriorate very quickly. The break up of the large estates has lead to the loss of most of the Victorian glasshouses in Wales, this gives those that remain an increased importance.

The Renovation Work:

The design brief for the renovation required that the Citrus House provided full and safe access to both public and staff. The challenge for the design team was to achieve this level of access whilst retaining the integrity and significant qualities of the listed building. These were: architectural composition; scale; the iron structural frame; the light weight timber detailing ; the scalloped glass tiling.

Scalloped Glass Tiles

Scalloped glass tiles were developed in the 19th C to reduce rot in rafters of glass houses by directing water away from puttied rebates. Though originally crown or cylinder glass it appears that all the remaining tiles in the citrus house were 3mm plate glass probably installed as replacements in 20th C. Research by the design team suggested that heat soaked toughened glass was the most appropriate to replace the glass with.

Lightweight Timber Rafters

Structural analysis of the timber members found that the strength of the lower jack rafters and main purlin failed to meet current standards with regard to imposed loading. The design team recommend the flitching of the principle rafters and main purlin together with the introduction of a lightweight steel purlin (‘T’) spanning between the principle rafters and to halve the span of the jack rafters. Though expensive, this approach will ensure that the overall the sizes of timber members remain as existing. All new timber would be imported Douglas Fir.

Cast Iron Structures

As several of the cast iron brackets were cracked, it was decided to record and log all cast iron members, temporarily remove them from the site, have them shot blasted and repaired as necessary before re-installing.

Heating and Ventilation

Winter heating is provided with large bore cast iron pipes at the front of the building and from a gas fired boiler in the ‘apple store’ to the rear. Summer ventilation is provided by the existing arrangement of opening sashes. The complete system was overhauled and now powered by an electric motor.


All mortars and renders used in the building are hydraulic lime based.

The Propagation House...

lies on the north side of the spine wall. Evidence remains to suggest that this house was built at the same time as the late 19th C rebuild of this Citrus House. For a period it fell into disrepair, it has now been renovated using the same principles that were applied to the Citrus House. All the original cast iron structural members remained, this has allowed it to be reconstructed as accurately to the original as possible.

Taking a step back in time...

it is easy to imagine the gardeners working in these wonderful greenhouses having a relatively comfortable time, especially during the Welsh winter months, working in the warm atmosphere. However the lifespan of many such gardeners was a short one. The chemical sprays, including arsenic, that Victorian gardeners used to kill the unwanted insect life in their glasshouses, ultimately did for many of the gardeners themselves.


© Margam Country Park