Laser scanning is a mass data collection technique, where millions of points can be collected quickly, producing quality of data and levels of accuracy unmatched by traditional methods.
The advance of technology has opened up new opportunities in surveying techniques, bringing substantial benefits to our historic built environment. Knowledge of the position, size, shape and identity of the components of a historic building or site is vital. For heritage projects, this provides a detailed archivable record prior to any intervention, assisting in the conservation, refurbishment or analysis process. The information provides a detailed framework for the assessment of the site’s significance, and a basis for further conservation analysis.
The conservation of a listed property traditionally begins with a time-consuming building survey that involves many manual measurements - accurate measurement is an extremely important part of this. Theodolite and tape measures have long been part of the building surveyor’s toolkit in this scenario. These traditional measurement methods are now being augmented, and possibly will be superseded, by laser technology.
The scanning equipment has improved in recent years, with increases in the speed of data collection, enhancements in the quality of the data, and the development of methods that allow the rapid survey of more difficult areas using modern survey techniques, often these buildings can now be surveyed within a working day allowing the next stage of works to commence almost immediately.
Benefits for heritage buildings
Heritage buildings often require much higher attention to detail, with complexities and intricacies that are hard to capture through manual surveying and measurements. Laser scanning offers considerable cost, programme and quality benefits as a result of the following benefits:
• reduces time surveying on site
• improves accuracy of measurement
• complex areas, curves and obstructions can be accommodated
• previously inaccessible areas can be surveyed
• less disruptive in occupied buildings
• provides information for BIM and other 3D models
• enables a more complete data-set, for potential expansion of client brief or other future needs thus reducing re-visits
• provides a snapshot record of the heritage asset
• improves health and safety on site
Old Shire Hall, Warwick
SNC-Lavalin’s Faithful+Gould business recently worked on a project where laser scanning measurement was put to excellent use. Old Shire Hall was constructed in the mid-18th century, remodelling and integrating aspects of an earlier 17th century building. Now Grade I listed, the building was a working law-court until 2010.
Warwickshire County Council has converted the Old Shire Hall into an events venue. Our team was appointed as designers, project managers and quantity surveyors for the refurbishment of the commercial kitchen and wedding preparation facilities and the upgrade of the building emergency services. A laser scan survey was commissioned and this accurately captured important data, including the period architectural details such as decorative stonework, cornice and ceiling roses. Inaccessible areas such as the voids within the attic were also accurately measured and recorded for the first time.
In an exciting development, the historic ventilation system located within the roof void was identified by our conservation specialist and subsequently preserved—illustrating the importance of applying fundamental conservation principles to historic services as well as historic fabric.
Using the technology in many sectors
The technology increasingly benefits projects outside of the heritage arena: for example, the transport, health, education, retail and commercial sectors. 3D laser scanning is now also used on new-build projects, to produce a record of existing adjacent buildings, buildings to be demolished and the topography of development sites. Capturing data from an early stage within a project can assist in the successful lodgement of planning applications, listed building consents and other legal matters such as The Party Wall etc Act and Rights to Light agreements.
Which projects benefit?
Faithful+Gould is at the forefront of the digital construction agenda, working with our clients to understand their key objectives and identify the appropriate methods and technologies which are able to achieve these. However, not every project needs the most sophisticated technology available. The choice of survey method should consider the size, complexity and accessibility of the asset in order to achieve the client’s purpose and aim. Not all projects require laser scanning and working with our team of Chartered Building Surveyors will identify the best survey methodology in order to meet the client requirements in the most cost effective and timely manner.