BUILDING RENOVATION USING LIGHT STEEL FRAMING

Renovation is an important social and economic requirement and is an increasingly important part of the UK construction industry. The use of light steel framing has found a niche market in this sector, particularly in extensions and adaptation of buildings.  Recent applications of light steel framing in over‑roofing and over‑cladding of existing buildings, infill walling in building conversions, and the use of modular construction to extend buildings are reviewed. Economic assessments have shown that the renovation work can be self‑financing in terms of energy savings and rental income over a 20 year period.

SCI and Corus are partners in a new RFCS project ‘ROBUST’, or renovation of buildings using steel technologies, which is aimed at addressing the key technical issues in this expanding sector.

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Over‑roofing or Roof‑top Extensions

‘Over‑roofing’ is a terms used for the creation of a new roof structure to an existing building[[1]]. The main reasons for over‑roofing are the poor performance of the existing roof (such as water leakage) and the desire to utilize the space in the roof, for example, for communal use or as new apartments. The form the new roof construction depends largely on whether or not the space is intended for habitable use.. The value of the new space created can pay for all the renovation work.

Over‑cladding

‘Over‑cladding’ is defined as the attachment of new cladding directly over an existing façade[[2]], and is differentiated from ‘re‑cladding’ in which the existing cladding is replaced. Over‑cladding is carried out in order to:

·       reduce the heat losses through the façade and to meet modern thermal regulations

·       improve the appearance of the building

·       arrest the deterioration of the existing structure or façade, including water leakage

·       minimise disruption to the occupants during the renovation process.

Modular Units in Renovation

Buildings may be extended easily using modular or ‘volumetric’ units which are self‑supporting vertically, but which are supported laterally by the existing structure. Modules are generally less than 3.6 m wide so that they can be transported without special escort and are easily lifted into place. Cladding can be pre‑attached, or can be installed conventionally on site.

The use of modular units in renovation applications is most well established in Scandinavia.  Interest in modular construction for building extensions is increasing in the UK, and recent applications include medium‑sized hotels and social housing projects[[3]]...

Economic Assessment of Over‑roofing and Over‑cladding

A full economic assessment of over‑roofing and / or over‑cladding savings must take into account the following annual savings and income, in addition to the broad social and environmental benefits. The readily quantifiable financial benefits are:

·       savings in heating bills for both the occupants and owner

·       increased rental charges due to an improved internal and external environment

·       increased revenue (or sales) from the creation of new habitable space or additional facilities

·       reduced maintenance and repair costs of the existing roof or façade.

Other demonstrable savings of these renovation projects, in comparison to the alternative of demolition and re‑building are the:

·       cost of having to re‑house the occupants temporarily

·       extra cost and disruption of demolition and re‑building in terms of site infrastructure, etc.

·       time delays required by demolition and re‑building

For further information, please contact

Mark Lawson
Professor of Construction Systems, SCI
Email: m.lawson@steel-sci.com
Tel: +44 (0)1344 631027