What is restoration?

Restoration is the building work that returns a structure or component of architectural, historic, technical or other cultural value to good condition, in a way that keeps as much of its original significance as possible. It usually concerns historic buildings, but bridges, interiors and furniture are restored too.

Restoration versus related terms

• Conservation: keeping something in the state in which it was found, mainly through maintenance and protection.
• Restoration: repairing with respect for the historic fabric, often with more substantial intervention.
• Renovation or refurbishment: renewing and upgrading, usually for the same use; heritage value is not the main driver.
• Reconstruction: rebuilding what has been lost, based on evidence and research.

Guiding principles

Dutch heritage practice uses a simple rule of thumb: conserving beats repairing, repairing beats restoring, and restoring beats replacing. In short, do as little as possible and as much as necessary. The Dutch body for restoration quality, Stichting ERM, adds principles that are widely shared elsewhere:

• Reversible: an intervention should be capable of being undone later.
• Compatible: new material must not damage the historic fabric, technically or visually; repairs should be weaker than the original.
• Like for like: same material and technique where possible.

In Britain, the Society for the Protection of Ancient Buildings, founded by William Morris in 1877, has long argued for the same cautious, repair-first approach.

Application: how to approach a restoration

1. Understand the building first. A historic building survey and statement of significance tell you what must be kept.
2. Check consent. In England, works to a listed building that affect its character as a building of special interest need listed building consent from the local planning authority. Rules differ in Scotland, Wales and Northern Ireland.
3. Talk to the conservation officer early, before drawings are finalised.
4. Use specialists experienced with traditional materials and techniques.

Common mistakes

• Repointing historic lime-mortared brickwork with hard cement mortar, which is harder and less breathable than the original and can damage it.
• “Improving” during maintenance with a different material or profile, which may turn a repair into works requiring consent.
• Restoring back to a supposed original state and stripping out later layers that are significant in their own right.

Related terms

• Listed building
• Conservation
• Reconstruction
• Renovation
• Building archaeology
• Repurposing

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