Are you wondering how historic building preservation works?
You’ve come to the right place!
In this Regional Foundation Repair guide, we’ll cover:
- The difference between conservation and preservation
- The benefits of preserving historic buildings
- How foundation settling impacts historic buildings
And much more!
So, if you want to understand how foundation movement affects the preservation of historic buildings, keep reading our guide below!
What Is Historic Preservation?
The appreciation of old and historic buildings in America is always apparent, but it isn’t necessarily followed up with the same enthusiasm for preservation and repurposing. The practice and process of preserving America’s historic buildings poses many challenges and sadly, in many instances, buildings are demolished due to demand for housing or commercial property. This doesn’t have to be the case, as shown in Miami’s Little Havana where the National Trust Research and Policy Lab has found building out vacant lots and utilizing historic vacant buildings could accommodate as many as 550 new businesses and 10,000 new residential properties. Opting to demolish rather than preserve doesn’t need to be the norm, and there is great scope for further preservation of some of the oldest buildings in the country.
The building preservation industry is becoming more important as buildings of significance age and need attention to retain their historic value and add to the vibrancy of our cities. The reasons for a building holding historic value are highly varied and can be specific to any given region or even an individual who once lived there. Let’s look first at historic preservation and what it entails.
Exploring Historic Preservation
Historic preservation is the practice of protecting, conserving and preserving buildings, sites, districts and even individual structures that hold local, national, culture, economic, social, political, architectural or archaeological historic value. This explanation alone shows the sheer scope of the field. We might naturally think that historic preservation is a task associated with museums and archaeologists, but it goes far beyond this.
Those working in the sector may be historians or archaeologists or they may be experienced builders and architects. The process of historic preservation involves research into the historic value of any site and the navigation of local, federal, and state guidelines for the treatment of historic buildings. The treatment of historic properties is governed by strict guidelines and restoration and preservation work can be highly technical and complex, with a need to try and make any restorative work sympathetic to the original build and in line with the processes used originally, too.
Historic Preservation History and Regulations
The importance of preserving historic buildings has been a consideration for the US government for centuries. The first formal activities of historic building work began around 1850, but there is evidence of less formalized activity back to the 18th century. The first building to ever receive historic designation from the US government was the Newburgh, NY property that served as George Washington’s headquarters during the Revolutionary War. Early decisions in preservation focused on the Revolutionary War and its landmarks as well as important figures such as Washington.
Since its foundation in 1949, the National Trust for Historic Preservation has been the central body tasked with the preservation of all buildings of historic significance, in different communities around the country. In 1966, the US government passed the National Historic Preservation Act, establishing the National Register of Historic Buildings (NRHP). This registry has provided private historic property owners with incentives to protect their own historic buildings and over 80,000 buildings are protected under the NRHP.
Understanding Conservation vs. Preservation
The terms conservation and preservation are often used interchangeably but, in the US, they have different meanings and should be considered as separate practices. The field of historic preservation focuses on preserving cultural or historic property. Work may include disciplines including engineering, architecture, landscape architecture, construction, advocacy, heritage tourism and archaeology. Historic preservation is guarded by strict regulations and may include the Secretary of the Interior’s Standard for the Treatment of Historic Properties.
Conservation relates to both environmental and cultural property. Environmental conservation is carried out by conservationists while cultural conservation is carried out by conservators. Conservators may work on historic building preservation and will carry out the physical work involved in preserving and saving a historic property.
Historic preservation work will include preservationists and conservators working together to help ensure the building is treated sympathetically and with its original design in mind.
Practical Benefits of Preservation
Preserving older buildings comes with many benefits, not least their historical significance and it’s worth keeping these points in mind when considering any preservation project.
1. Historical Importance
We cannot underestimate the importance of recognizing and respecting our history. Commemorating the past is important and it can also have a monetary value if visitors are interested in visiting the property and enjoying a piece of history. The esthetic value of historic buildings and architecture is important, too.
2. Commercial Value
Preserving a historic building can be an opportunity to renovate and restore precious items, materials and more, which cannot be recreated or are too expensive to replicate. Preservation allows you to reuse and build upon the existing building’s structure and foundations, and often, higher quality materials such as old growth wood can continue to be used.
Opting for preservation over demolition gives you the chance to make the most of the existing materials, minimizing the carbon impact of the building. Less construction and demolition debris is produced and there is less need to provide new materials for the building. Reusing and repurposing existing buildings is a sustainable practice, to which many are committed due to the huge environmental and carbon impact of demolition and building from scratch.
4. Energy Saving
In the same area as point three, preserving historic buildings minimizes excess energy use. There is no need to waste energy on demolition and new construction, and embodied energy from within the building materials and assemblies can be reused.
Common Structural Problems in Historic Buildings
Historic buildings often experience the same problems over time. The building has been resting on its foundation for centuries and so it is important to periodically check for issues with the structure and ensure any concerns are quickly dealt with. Below we’re looking more closely at the most common structural problems found in older buildings:
Foundation settling is usually found in the form of diagonal cracks in plaster or the foundation as well as sagging floors, exterior doors and windows. Foundation settling occurs when the foundation’s footing fails by sinking downwards or moving laterally from where it was originally placed in the ground. The foundation footing is a masonry structure that sits beneath the foundation wall and supports the wall, taking its name from the foot, which supports a leg. The property’s masonry wall atop the footing will sink as the footing fails.
In historic properties, foundation settling often occurs when there has been too much water build up around the foundation footings. However, the same can happen in arid and dry regions, as prolonged drought can shrink the soil surrounding the footings.
Foundation settling in small amounts is not a huge cause for concern and does not mean the foundation as a whole has failed.
Failed or damaged masonry can be a problem in historic buildings, as restoring it in the same way is not always possible. Masonry foundations, construction from brick, concrete block or poured concrete are prone to damage and failure over time. Moisture getting into the masonry is one of the most common problems and once it gets in, it can freeze and cause cracks or spalling of the stone, bricks or concrete.
The mortar between foundation bricks, concrete block or stones can also ail and this can result in walls bowing inwards. This is why repointing is a key task in masonry restoration and preservation, critical in restoring and maintaining the health of the building’s foundation.
Bowed Foundation Walls
Foundation walls can bow inward over time and symptoms of this include sagging floors, cracked plaster and buckling to hardwood flooring. Water build-up is the most common cause of bowing, as hydrostatic pressure builds up outside of the walls and forces the foundation inwards. Walls can also bow due to overgrown tree roots.
Bowed walls need to be treated carefully and often require the expertise of a structural engineer. The wall may need to be disassembled and reassembled in parts and for old buildings, it isn’t unusual to need some walls replaced.
Modern Techniques for Historic Preservation
Historic preservation work in the US is still governed by standards set out in 1977, so it’s clear a more modern approach may be necessary to ensure all is done to restore and preserve buildings from our history. Rapid urbanization, the decline of rural areas and the growth and value of real estate as a business has led to historic buildings not always getting the treatment they deserve. Demolition is often thought of as the first option when perhaps there should be more consideration for many buildings. America still only categorizes its old buildings as historically significant, or not, and if it’s the latter, demolition is much more easily planned.
In Britain they have a tiered grading system which protects buildings of exceptional importance, particularly important buildings of more than special interest and buildings of special interest and this allows for a much wider range of buildings to have protection and more grants and funding is available to preservation work. It is a model we could consider in the US. Similarly, there are a growing number of technologies that can help preservation efforts.
Advances in Restoration Architecture
Restoration architecture covers a wide range of different innovative and exciting new ways of improving the preservation process. Lasers, virtual reality and 3D printing are just three tools in use by leading architecture and construction firms. Notable examples include:
- Notre Dame Cathedral – when the world famous Notre Dame Cathedral in Paris caught fire and was partially destroyed in 2019, restoration efforts were immediately begun. Amazingly, a decade earlier, an architectural historian and computer scientist team laser-scanned every inch of the cathedral, inside and out. This data was converted into three-dimensional forms and has been able to be used in restoring the cathedral as accurately as possible.
- Open Heritage Project – utilizing virtual reality and 3D printing, the Open Heritage Project combines the talents of San Francisco engineer Ben Kacrya and Google. Kacrya’s company CyArk has teamed up with Google to show off 27 different sites of historic and heritage importance across 18 countries. The most exciting thing about this project is they have been able to recreate sites that have already been destroyed and offer virtual 3D experiences to visitors from around the globe. The detailed nature of their scanning can also help to identify areas where there is damage and pinpoint places for further restoration.
There are further advances in the use of 3D printing and laser technology to help construction and preservation companies find the most appropriate and sympathetic approaches to restoration. Digitally recording historic buildings helps to ensure there is a blueprint for restoration in the future too, so this is a technique which should be considered for all projects where possible.
Preservation for History and Practicality
The preservation of our historic buildings is a great way of capturing a piece of our history and ensuring it is not forgotten about. Historic architecture and building methods can be used for future construction projects too and traditional techniques may have a resurgence as new generations of designers and architects develop. It’s also important to remember the environmental impact of preservation, with less energy expenditure and waste produced in a well-managed restoration project than demolition and reconstruction.
Preserving and renovating historic buildings could also play a role in dealing with the homelessness issues in the country. The White House figures show over 250,000 Americans are classed as homeless while there are 17m potential homes standing empty around the country. A good percentage of these will be old and may seem ready for demolition, but with the right preservation techniques and attention, they could become busy homes again.
In America, we do have a problem of recognizing the importance of our old buildings and classifying their historical significance, but even when this is the case, the benefits of restoration and preservation can be considered worthwhile from an economic perspective.