Sustainable building design for Chithurst Buddhist Monastery, Sussex

Building Chithurst’s Carbon Neutral Green Oak Meditation Dhamma Hall

The site of a ruined coach house set within 150 acres of Sussex forestry has become the chosen place for Chithurst Buddhist Monastery’s long needed new Dhamma* Hall (meditation hall). The Dhamma Hall is now a place where natural balance can be realised through silent meditation.  ‘Dhamma‘ is a very significant word in Buddhism: it means both the teachings of the Buddha, the nature of ultimate truth, and the characteristic of a phenomenon.  The phrase ‘the way it is’ is sometimes used to cover all its meanings: it carries suggestions of natural balance in human and macrocosmic terms.

Meditation is the heart of Buddhist practice, and yet the monastery, based at a Victorian house in Sussex lacked a suitable space for this important daily routine and was using an inadequate large room in the existing house.  Apart from being too small for the number of people who liked to join the monks and nuns (sangha) in their evening meditation and hear the teachings, the room was also next to the office and reception area – with their inevitable noise and traffic.

Chithurst’s Carbon Neutral Green Oak Hall
green oak Dhamma Hall

From an architectural point of view, simplicity, and an emphasis on natural unfinished materials were chief requirements for the new Dhamma Hall.  These fitted in well with the renunciate ethos of the sangha. (The monks and nuns take vows to never personally handle money, to own no personal possessions other than their monastic robes and eating bowl, to only eat one main meal a day before midday and to remain silent during sustained periods of meditation retreat.)  To acknowledge this disciplined monastic ethos the building would have to be as clear as possible of visually distracting detail, noisy catches, switches and hinges.

Aside from this, but just as importantly it would also have to fit the functional requirements of seating up to 200 – 250 people, and be comfortable enough for sitting on the floor. Monks and nuns may sit for hours virtually motionless in meditation, therefore if it were draught-free, and contained a ‘neutral’ warmth without inducing drowsiness it would be a blessing indeed.  On top of this the building as a whole had to fit in with the style of the local architecture in order to comply with stringent local planning laws.

The monastery belongs to a lineage of ‘forest monasteries’ that is based in N.E. Thailand, but has several overseas branches. This particular forest based monastic lineage emphasises the benefits of living in harmony with nature.

In order to learn ‘inner balance’ one is recommended to understand that one is part of a much larger cosmic balance that includes the natural world.

In the severely ravaged ecologies of S.E. Asia, forest monasteries, (which comprise simple huts) remain a refuge for wildlife and native flora; and the monks who have ‘renounced the world’ nevertheless support both environmental protection and reforestation.  Chithurst Buddhist Monastery is a good example of this: with 150 acres of chestnut coppice, the monastery has for many years been restoring the estate to native woodland.

Eco Arc where selected for the project by the monastic client as we had already worked on a sister monastery in Northumberland, and had strong Buddhist sympathies, which include co-running a York based meditation group, working on fourteen other UK Buddhist projects and leading eighteen Buddhist based mountaineering trekking expeditions in the Nepal and Tibetan Himalayas.

Structural Design Ideas

During initial dialogue, the client sangha outlined the concept of a Hall that carried echoes of trees and groves. From this we came up with a design resembling a traditional Sussex aisled barn in which a series of stout wooden columns support the roof. The end of the ‘grove’ of aisled columns framed a large alcove for the Hall’s presiding image – of a Buddha seated in meditation. The open roof structure acts like a canopy of tree branches refracting light from above and allowing shafts of light to fall on the natural stone floor.

Some three years before the frame was built we went into the monastery woods to select out curved timber for the frame. A number of trees with pronounced curves were marked and felled, through and through sawn, and sticked and stacked for cutting the braces when needed. Air-drying the timber in this way helped minimise gaps occurring in the joints through shrinkage, which is more problematic especially in braces.

The main timbers are of green oak. These were shaped, installed and pegged together while green by The Green Oak Carpentry Company who are based just 5 miles from the monastery. This oak came from trees in the monastery grounds that had either been blown over by gales, or were due for felling (through thinning).  Other timbers and planking are of sweet chestnut, which resembles oak in its durability and appearance and is found in abundance in the monastery’s woodland.

The triple aisled barn form has nine structural bays, set within super insulated masonry walls. The trusses in the main hall are Crown post type, which is a true mediaeval style of roof, chosen because it most echoes the tree form with the braces curving and rising up through the layers of the structure

The timbers were sawn on site with a mobile band saw. Cutting and shaping the unseasoned oak is much easier than using seasoned timber. Historically it would be virtually unheard of to find dry timber used in a frame. The draw bored mortise and tenon joint is vital to the success of green oak framing as the pull on the joint when assembled, helps mitigate the shrinkage and hence gaps that occur in drying. Shrinkage cracks that occur in the drying of the timber are deemed to be a part of the aesthetic of green oak framing and are accepted as the norm.

Once assembled the frame was sand blasted to clean it, which removes the dirt, and softens the band-sawn surface. Overall the timber has taken on a pale straw-coloured hue and is undoubtedly hugely appealing to the senses as the growing popularity of these structures shows.

Ecological Design Features

In keeping with monastic frugality and ecological principles, a low energy building fabric is achieved with 200mm thick insulation in the walls and 300 mm insulation in the roof, triple-glazed low E argon filled glass in the windows and doors, draft lobbies to all entrances and air tight construction detailing to mitigate incidental air infiltration.  In technical terms, the building is intended to be carbon neutral. (Zero CO2)

The heavy weight, high thermal mass, wide cavity walls are super insulated and made from recycled natural stone salvaged from the coach house that formerly occupied the site.  The walls are finished internally with self-coloured 1 to 2.5 lime / sand render.  Reclaimed clay pan tiles cover the roof, which was super insulated to a depth of 300mm with recycled newspaper between Masonite I beams over the top of the oak structural frame.

The energy efficient building’s thermal mass and super-insulation naturally keep it cool during the summer and warm in winter. Additional warmth is provided during the winter by under floor heating. The heat source itself is a wood-fired Zero CO2 biomass boiler, which delivers heat where it was most needed for seated meditaters – through piping under the stone floor.

The Nordist / Bioenergy Technology log fired boiler heats the monastery dormitories, kitchen, offices, and the main meditation hall. The fuel is provided from the labour of the Buddhist monks with timber extracted from the monastery woodland. The boiler can generate an output of up to 90 kW. The cross-fired log burner operates at efficiencies comparable with fossil fired burners.

The floor itself is made of slabs of sandstone from a quarry that was coming to the end of its 500- year life and converting itself into a wildlife reserve. Rainwater is collected to fill a naturally formed wildlife pond. Toilet wastes are naturally treated on site by a Diamond sewage treatment system where out put nutrient liquids are filtered back to the land via a leach field drainage system. In the final phase of building work, the cloistered walkway will be completed. Funding will be raised to install photovoltaic panels to convert energy from the sunlight to Zero CO2 electricity which will power the building’s lighting and hearing loop p.a. system.


In many ways the materials and their sources echoed similar themes.  From a spiritual point of view, such congruence feels very auspicious. It has also been inspiring to note the human factors involved. The whole design teams sensitivity, flexibility and attention to detail has made for easy and enjoyable dialogue. The project manager, Nick Scott, lived on site and put six years of intense work into the project without any salary. Local self-employed tradesmen, carpenters, masons and craftsmen were directly employed instead of using one main contractor. The monks and nuns did much of the unskilled building work themselves.

The whole project was funded through donations, and supported by many acts of voluntary work – including the making of the statue of the Buddha himself who now sits, serene and smiling; an image in human terms of the natural balance that the Hall supports.

Even during the recent busy opening ceremonies, the Hall’s ambience was pervaded with silence and some people sensed the calm interior space as sublime.  In our increasingly busy and chaotic world we hope this simple sustainable building will provide a safe, quite haven for meditators to contemplate our shared quest for oneness, for the benefit of all beings.