Historic Gardens and External Features: Garden Buildings, Statuary, Walls and Glasshouses

A conservation guide to the features of historic gardens and the spaces around old buildings: garden buildings and glasshouses, statues and urns, walls and ha-has, gates and railings, paths and steps, water features and street furniture. It covers how they deteriorate, how to maintain and repair them, and the protections that apply.

Building Restoration Index — Technical Library. By Paul Stenning and Mike Walters, Historic Buildings Advisors, Tuscan Foundry Products.

Understanding a historic garden

A historic garden is a designed landscape, and its features make sense as part of the whole design.

• Find out how the garden developed: old maps, estate plans, photographs and garden histories help.
• Identify structures and features that survive, even as fragments: walls, terraces, paths, steps, water features, garden buildings and statuary.
• For larger or more significant gardens, a conservation management plan sets out what matters and how it should be cared for.
• Landscape architects and garden historians can advise on restoring lost features.

Designations and protection

Historic gardens and their features can be protected in several overlapping ways.

• Registered parks and gardens. In England, Historic England’s Register of Parks and Gardens of Special Historic Interest grades sites I, II* or II. Registration doesn’t add a separate consent regime, but it is a material consideration in planning decisions, and The Gardens Trust is consulted on planning applications affecting registered sites. Wales, Scotland and Northern Ireland have their own registers or inventories.
• Listed structures. Garden buildings, walls, gates, statues and urns may be listed individually.
• Curtilage. Structures within the curtilage of a listed building, built before July 1948, may be treated as part of the listing.
• Conservation areas and trees. Trees in conservation areas and trees under preservation orders need notice or consent before work.
• Scheduled monuments. Some garden earthworks and archaeological features are scheduled.

See our guide to Listed Building Consent.

Garden buildings

Summerhouses, temples, follies, gazebos, boathouses and estate buildings are often lightly built, rarely heated and poorly maintained, which makes them vulnerable.

• Roofs and rainwater. Small roofs with failed gutters and downpipes soon let water into walls and timbers. Keep rainwater goods clear and repaired, and make sure water is carried away from the base of the walls.
• Ventilation. Closed-up buildings suffer from condensation and rot. Ventilate them and open them up on dry days.
• Timber. Garden buildings often have timber frames, cladding or joinery close to the ground. Inspect for rot and repair with matching timber.
• Masonry. Use lime mortars and like-for-like stone or brick. See our guides to historic brickwork and historic stonework.
• Vegetation. Ivy, climbers and tree roots damage walls and foundations. Control them before they take hold.

Glasshouses and conservatories

Historic glasshouses, orangeries and conservatories combine timber, iron and glass, and each material needs regular care.

• Timber glasshouses need regular painting and repair of glazing bars and sills, which are the first parts to rot.
• Cast and wrought iron structures need corrosion treatment and painting, and broken castings can often be copied. See our guide to historic ironwork.
• Glass. Keep historic glass where it survives. Replacement glass should match the thickness and character of the original, and safety glass may be needed in public areas.
• Rainwater. Gutters and downpipes on glasshouses are small but essential. Blocked gutters cause overflowing and rot in timber and corrosion in iron.
• Heating systems. Historic boilers, pipes and flues may survive and be significant.

Statues, urns and ornaments

Garden statuary is made of stone, lead, bronze, cast iron, terracotta and artificial stone, and each material needs different care.

• Stone. Frost, water and soluble salts break down stone surfaces. Keep water from collecting on and in statues, and avoid harsh cleaning.
• Lead. Lead statues can sag and distort under their own weight as internal armatures corrode. A conservator can assess and support them.
• Bronze and cast iron. Corrosion should be treated and the surfaces protected with suitable waxes or paints.
• Terracotta and artificial stone. Vulnerable to frost and impact. Repairs need specialist materials.
• Winter protection. Breathable winter covers protect vulnerable stone statues from frost and rain. Avoid impermeable sheeting, which traps moisture.
• Bases and fixings. Check that statues are stable, with sound plinths and fixings, especially where the public has access.
• Lichens and biological growth. Gentle removal may be appropriate in some cases, but harsh biocides and scrubbing can damage surfaces. Take advice from a conservator.

Theft and security

Garden statuary, lead features and metal gates are valuable and portable, and theft is a real risk.

• Photograph and record every piece, with measurements and distinctive marks.
• Forensic marking and secure fixing to plinths deter theft.
• Check insurance covers garden features at their true value.
• If items are stolen, report them to the police and to salvage and art loss registers.
• Buyers of reclaimed garden ornaments should ask for provenance.

Walls, ha-has and terraces

Garden walls, kitchen garden walls, ha-has and terrace walls are structural features that are often taken for granted.

• Copings protect walls from water. Repair and reset failed copings before the wall below is damaged.
• Use lime mortars for pointing and rebuilding, matching the original.
• Retaining walls and ha-has can bulge and collapse if drainage behind them fails. Get engineering advice for movement.
• Tree roots and climbers are a major cause of damage.
• Kitchen garden walls sometimes contain flues for heating, and may have historic fixings for training fruit trees.

Our guide to historic stonemasonry covers wall repair in more detail.

Gates, railings and ironwork

Gates, railings, garden furniture, plant supports and bridges are often made of cast or wrought iron, and they last for centuries if painted and maintained.

• Keep paint in good condition and deal with rust before it spreads.
• Repair broken castings by copying them, rather than replacing whole runs.
• Check gate hinges, posts and fixings, as their failure can make gates dangerous.
• Cast iron garden benches and furniture can be repaired and repainted.

See our guides to historic ironwork and paint systems for exterior historic metalwork.

Paths, steps and surfaces

Historic paths, steps and edgings are an important part of a garden’s design and are easily lost to modern resurfacing.

• Keep traditional materials such as gravel, setts, cobbles, flagstones and brick where they survive.
• Uneven steps should be reset rather than replaced, with attention to safety for visitors.
• Drainage of paths and terraces prevents water collecting against walls and buildings.
• Decorative tiled or pebble paths may need specialist repair.

Water features

Fountains, cascades, ponds, canals and their pipework are among the most complex garden features to maintain.

• Leaks from linings and pipes undermine surrounding structures.
• Puddled clay linings need to be kept wet and protected from roots and burrowing animals.
• Historic pipework, valves and pumps may survive and be significant.
• Ice can damage stone basins and fountains, so drain or protect them in winter.

Street furniture and estate features

Lamp posts, bollards, boundary markers, troughs, drinking fountains and pumps are part of the historic environment around buildings, and many are listed.

• Repair in place rather than replacing with modern equivalents.
• Cast iron street furniture can be copied from surviving examples where pieces are lost.
• Check ownership and responsibility, which may lie with the local authority or another body.

Wildlife and trees

Historic gardens are often important for wildlife, and this affects how and when work can be done.

• Bats roost in garden buildings, trees and walls, and all bat species and roosts are protected by law. Get a survey before works that might affect them.
• Nesting birds are protected. Avoid work to hedges, climbers and trees during the nesting season.
• Veteran trees can be significant parts of the garden design and important habitats.
• Balance wall and building repair with wildlife needs, for example by timing work carefully.

Maintenance and choosing specialists

A simple annual inspection of every garden feature, recorded in a log, prevents most serious decay.

• Check roofs, gutters, copings, statues, ironwork and paths in autumn and spring.
• Clear leaves from gutters, drains and outlets on garden buildings.
• Use specialists: stonemasons and sculpture conservators for statuary, blacksmiths and foundries for ironwork, joiners for glasshouses, and landscape architects for restoration plans.
• For grant-aided or significant work, an architect or landscape architect experienced in historic gardens should specify and supervise.

Common mistakes

Mistake	Consequence
Neglecting gutters and drainage on garden buildings	Rot in timbers, damp walls and corroded ironwork
Pointing walls with cement	Faster decay of brick and stone
Covering statues with impermeable sheeting in winter	Trapped moisture and frost damage
Harsh cleaning or biocides on statues	Loss of surface detail and damage to stone
Leaving metal statuary unrecorded and unsecured	Theft and difficulty recovering stolen items
Replacing historic paths with modern surfacing	Loss of character and historic materials
Letting ivy and tree roots grow into walls	Cracking, loosening and collapse
Replacing whole runs of railings when a few castings are broken	Unnecessary loss of historic ironwork
Working on trees or buildings without checking for bats and nesting birds	Breaking wildlife law and delaying work
Assuming garden structures are not protected	Unauthorised works to listed or curtilage structures

Find a specialist

Specialists in the Building Restoration Index who work on historic gardens and external features, grouped by the part they play in a project:

Contractors and craftspeople

• Sculpture — conservation and repair of statues and garden ornaments
• Stone and Stonework — walls, steps, balustrades and stone features
• Metalwork — gates, railings, garden furniture and iron structures
• Conservatories & Glasshouses — repair and restoration of glasshouses and conservatories
• Brickwork — garden walls and brick structures
• Fine Joinery — timber garden buildings and glasshouse joinery
• Street Furniture — lamp posts, bollards and estate features

Architects, surveyors and engineers

• Landscape Architects — restoration plans for historic gardens and landscapes
• Architects — garden buildings and consent
• Structural Engineers — retaining walls, ha-has and garden structures

Consultants and designers

• Heritage Consultants — significance and heritage statements
• Architectural Historians — history of gardens and garden buildings
• Archaeologists — garden archaeology and lost features

Investigation and recording

• 3D Scanning — recording statues and garden structures
• Aerial Drone Surveys — surveys of large gardens and parks
• Materials Analysts — analysis of stone, mortars and metals

Material suppliers

• Architectural Salvage — reclaimed garden ornaments, stone and ironwork
• Stone — matching stone for repairs
• Lime Mortars & Plasters — lime mortars for walls and masonry
• Paints & Finishes — paints for ironwork and timber

Advice and training

• Organisations — national amenity societies and trade bodies, including those that publish technical advice
• Courses, Training & Events — courses and events for owners, contractors and professionals

Further reading from Tuscan Foundry

• The history of paint on period buildings and ironwork
• Heritage colours for cast iron by period
• Ten signs your cast iron guttering is failing

Related guides

• Historic ironwork: railings, gates and castings
• Historic stonework: decay, repair and cleaning
• Historic stonemasonry: repairing stone walls
• All guides in the Technical Library

The Index lists specialists without endorsement; check experience, references and insurance before appointing anyone. Specialists can add a free listing.

Frequently asked questions

Are historic gardens protected by law?

Registered parks and gardens are a material consideration in planning, and structures within them may be listed. Trees may be protected in conservation areas or by preservation orders. Check designations before work.

Do garden walls and statues count as listed?

They can be listed individually, or treated as part of a listed building if they are within its curtilage and were built before July 1948. Check with the local planning authority.

How should I protect stone statues in winter?

Use breathable winter covers that keep off rain and frost while letting moisture escape. Avoid impermeable sheeting, which traps moisture.against the stone.

Should I clean lichen off a garden statue?

Not without advice. Lichens can be part of the character and removal can damage the surface. A conservator can advise whether, and how, to remove them.

Why is my lead statue sagging?

Lead is soft and heavy, and the internal iron armature may be corroding. A sculpture conservator can assess and support it before it distorts further.

How do I stop garden statues being stolen?

Record each piece with photographs and measurements, fix them securely to plinths, use forensic marking and check your insurance. Report thefts to the police and loss registers.

How should historic garden walls be repaired?

With lime mortars and matching brick or stone, keeping copings sound to protect the wall. Bulging retaining walls need engineering advice.

Can I repair a Victorian glasshouse?

Usually, yes. Rotten glazing bars and sills can be replaced in matching timber, iron can be treated and repainted, and historic glass kept where it survives.

What is a ha-ha?

A sunken wall and ditch that keeps livestock out of a garden without interrupting the view. Ha-has can bulge or collapse if drainage behind them fails.

Do I need permission to fell a tree in a historic garden?

If the tree is in a conservation area or protected by a tree preservation order, you need to give notice or get consent. Work in registered gardens may also need planning advice.

Can I replace broken cast iron railings?

Repair them first. Broken castings can usually be copied from surviving pieces, so only damaged sections need replacing.

Why are gutters on garden buildings important?

Small garden buildings and glasshouses have little protection from the weather. Blocked or broken gutters soon soak walls, rot timber and corrode iron.

Who restores historic gardens?

Landscape architects and garden historians plan restoration, with stonemasons, sculpture conservators, blacksmiths, joiners and gardeners carrying out the work.