Steel windows are ideal for warehouse refurbishment - By Matthew Hahn, President, Steel Window Association

The latest buildings to receive the attention of preservationists are the late 19th century warehouses which once dominated our industrial cities and riverside docks and now cry out to be returned to their former glory. It is not only the conservationists who want these buildings kept, planning officers also want to see them left as part of the towns and cities that were largely created from the wealth that these buildings originally produced.

The major trend of recent years is to convert warehouses into modern loft-style apartments which attract premium prices.  But even when a modern building is planned on the site of one of these warehouses, planning departments will generally demand that those fascias of the buildings which overlook a public thoroughfare are left intact.

In these situations refurbishment is called for and with it preservation or replacement of the existing fenestration. Most of the windows in these old warehouses were either cast iron or cast steel. In both cases extremely narrow glazing bars were obtained - far narrower than is possible now from other window materials.

However, modern steel windows can be made to replicate the windows made over 100 years ago. The fine sight lines and the small pane windows that were then popular can readily be produced. Integral tee glazing bars can be provided in the same idiom as the originals without restoring to fake "Georgian bar" effects within double glass units.

Another peculiarity found in some of these warehouse windows is a shaped head. The soldier course at the top of the frames was often a semi circle or certainly shaped. Steel lends itself to be rolled very easily into any shape, and there is no problem in fixing steel windows directly to the brickwork.

Steel windows are all made to order, so the variations in size which are evident in the hand made windows in the old warehouses can be repeated without creating problems of trying to make all the openings for windows a similar size. Even in the more modern of the warehouses, the floor heights and therefore the window depths are often reduced towards the top of the buildings. These changes in dimension present no problems to steel window manufacturers.

While the steel window can replicate what went before in appearance, it will bring with it all the advantages of modern windows. The steel itself is galvanized to prevent rusting and it is can be factory finished with a polyester powder coating which eliminates site painting.

The continuing relevance of steel windows has recently been confirmed with the issuing of a major revision to a 20 year old British Standard. BS.6510 : 2005 has been drawn up by British Standards Institution technical sub-committees B/538/1 & 2 and represents a full revision of the 1984 Standard to reflect the way in which steel framing solutions have progressed in response to demands for improved performance as well as greater design freedom.

Amongst the most significant changes within the new Standard are specifications on energy conservation, acoustic insulation and fire safety, together with an expansion of scope to include all steel profiles.  It embraces all the relevant harmonised European standards published to date and takes into account the forthcoming European product performance standard for all windows and external pedestrian doors.  It goes on to give information on how specifications relate to the European Construction Products Directive, and consequently enable the CE mark to be correctly applied to steel windows when this becomes a requirement.

Total window replacement is not always the answer.  Old cast iron and steel windows in some of the warehouses might look in bad shape but they can sometimes be fully refurbished either in situ or back in the window factory. It means sand blasting the windows and repainting them - or galvanizing them if they have been removed; cleaning and replacing the fittings, which are often solid brass or bronze, fitting draughtproofing and making sure that the opening lights fit securely into the frames.

Tel: 020 7637 3571

www.steel-window-association.co.uk