Restoration at Hestercombe

When visiting old and historic properties, most of us marvel at the demands and challenges they make of their owners. These are magnified when they require renovation or restoration. Whilst there is much information about energyefficiency and new-builds there is less for older-properties but a just-completed project at Hestercombe Gardens (Somerset) sets out to remedy this. A seventeenthcentury Watermill and 18th-century Barn have been restored and converted into an Educational Centre for Sustainable Energy (opened in 2010).

Hestercombe has become well-known for its unique collection of gardens spanning 3 centuries of garden-history and design, all brought back to life over the past 20 years. There’s a 40-acre, Georgian, Landscape Garden (created 1750-1786), in the combe (valley), north of the House; a Victorian Terrace Garden south of the House (laid out 1873-1878); and an Edwardian Formal Garden created by Lutyens with planting by Jekyll, made 100 years ago and considered one of their finest creations. The Estate has also been virtually self-sustaining over the years, using stone from its own quarries for the buildings, fuelling fires with timber and charcoal from the woodland and generating its own water-power via wheel and turbine in Victorian times. It makes an ideal and appropriate location for the Centre.

The restoration project was ambitious. In March 2009 when work began, the buildings (the only remaining, unrestored complex on the estate), were derelict and last-used as pigsties. Initially, a survey was commissioned from The Centre for Alternative Technology (CAT) to advise on ways to reduce the carbon foot-print and suggest sustainable-energy strategies. ‘We wanted to reduce our on-going and future energy needs and manage the buildings as economically as possible’, explains Philip White, Chief Executive of The Hestercombe Gardens Trust.

The conversion was focussed on sustainable restoration, typifying the challenge – or minefield? – of adapting ancient, historical buildings for this century. ‘We considered the building’s infrastructure – insulation, lighting, heating etc, continues Philip, ‘and how it would operate in practice. The processes we’d need to manage and maintain it. We wanted to restore the buildings sympathetically and unobtrusively whilst making them as energy-efficient as possible. They are Grade II-listed, and designed in-part by Lutyens, so it wasn’t straightforward. We were very fortunate with our architect who found subtle and innovative ways to resolve sometimes apparently-conflicting demands.’

Robert Battersby from Architecton has been the consultant-architect for the project and specialises in this sort of restoration. ‘With historic buildings you should still see and feel the original outlines, shapes and forms. It’s only when you start looking critically that you might notice what’s actually been done. You’re seeking to draw out the spirit of the old [building] whilst at the same time making new – and sensitive – insertions to accommodate changed functions. Don’t replace timbers unless it’s absolutely necessary. Try and make any repairs subtle, using the same trades and methods as were used originally to create the building.’

What examples are there of these principles at the Mill & Barn?

In The Mill, the entire first-floor had gone, so new, steel, flitch beams sandwiched in oak were used when replacing it. ‘That way, we had both strength and appearance’, says Robert. ‘And in the Barn roof, a complex scarf-joint had to be made to replace rotten elm with new oak and according to the foreman, Steve Smith, this was probably the most difficult job in the restoration. The original building material was a pinkish stone, so any new-building has been done in a contrasting blue-brick so that the original form of the buildings is still clearlydefined. Despite the extensive work required both structurally and internally, care has been taken to retain the Lutyens gables which are focal points when seen from both the Edwardian Garden and the Landscape Garden in the valley.’

What about conserving heat and energy, often difficult in older buildings?

Robert stresses the importance of insulation. ‘Although the roof-structure was OK in the Barn, we raised a new roof above the existing one to get significantly more insulation in and still maintain an appropriate outline when seen from outside. The roof in the Mill needed a completely new structure so it was easy to put in more insulation on the inside than Building Regulations require.’

The mantra is ‘Insulate, insulate, insulate’! As well as the roof, there is insulation under the floors. And the more you can reduce heat-loss, the less energy needs to be consumed to heat your building. Burning wood – logs, pellets or chips – is considered ‘good’ but if you have limited supplies (as at Hestercombe where the logs come from the sustainably-managed woodland), or just want to reduce costs, then ‘Minimise Heat-loss’ is another rule. Small lobbies have been created inside all the external doors in the Centre, another very straightforward energy-saver. Dependency on artificial light is minimised by using substantial, oak-framed, fullsize windows and roof skylights. ‘This maximises the natural-light and sometimes it’s just simple measures like these that make a difference’, says Robert. ‘So don’t forget to check your window-seals too!’

Inside the Centre, displays show how previous generations used renewable energies and inform about contemporary, cutting-edge techniques for today. The 1895 water-wheel was restored in-situ and you can discover how this and the turbine provided energy for a corn-mill, an apple-crusher and a timber saw-bench. You can also see the new biomass-boiler, heating a 2,200 litre, heavily-insulated tank supplying the under-floor heating. ‘People feel comfortable at lower temperatures with under-floor heating’, explains Philip, ‘so it’s more energy-efficient. We’ve 100-acres of woodlands. As well as fuelling this boiler, they also provide charcoal and timber for income. We regularly coppice and re-plant, particularly hazel which is an important habitat for dormice. We’ve plans to establish a new cider-apple orchard too. There’s no solar-heating in the Centre because The Mill is overshadowed by trees so it wouldn’t have been efficient here but we’re looking at it for the greenhouses and Visitor Centre so it may come in the future.

‘We’ll have information-boards around the site explaining what we are doing. We want to put out simple and clear messages about the practical things we – and you – can do. There are going to be some very big compost heaps to see! As a matter of principle, all the scrap-metal was sent off-site for recycling. Everything else was recycled here. Even the concrete was crushed to create woodland tracks and improve public access. Our aim throughout has been to reduce energyconsumption, improve the environmental sustainability of the property and maximize cost-savings.’

Hestercombe is not just a tourist attraction but an important educational centre. An Education Development Officer was recently appointed. Working with The University Centre Yeovil, Hestercombe offers a Foundation Degree in Historic Gardens and Heritage Horticulture as well as B.Tech courses in Amenity Horticulture and Garden Design.

Hestercombe also works extensively with local schools and community groups. This Educational Centre, demonstrating both historical and contemporary approaches to sustainable energy and conservation, complements its existing educational activities and extends them further. A documentary film (DVD), has been produced for students of Further Education, Higher Education, Continuing Professional Development and skills-based audiences. Recorded throughout the restoration, it details the processes, the materials and the skills as well as the overall benefits of the range of sustainable-energy systems. It will be shown in the Centre as part of a package for group educational-visits.

‘There’s lots of scope for the adaptable re-use of old buildings like ours’, says Philip White. ‘Some 20% of UK housing stock is pre-1919. We hope what we’ve done here will inspire others interested in these older, often historic properties.’

© Helen Harrison

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