Making additions to existing buildings can be fraught with difficulties – planning concerns over the proposed scale and visual relationship between old and new, the conjunction of different materials, the anxieties of neighbours who fear being overlooked being just a few of the challenges faced in even the smallest project. And all this even before trying to find suitable, contractors able to work within the proposed cost range.
Yet the number of extensions continues to rise, partly as a result – until recently – of spiralling house prices and the difficulty of finding affordable alternative accommodation and partly because the way we use our homes continues to change.
It would be untrue to suggest that extending a house is an inexpensive option, however, and nowadays the addition of even a small room – depending on the design and materials used – can have a considerable cost. For these and other reasons, the use of timber in new house extensions has increased significantly in recent years and, in parallel with this rethinking of material appropriateness, so too has the degree of design adventure employed by architects in the UK.
The opportunities are not purely domestic though – developers working with existing buildings have recognised both changes in fashion and the need for more sustainable solutions when making additions. A good example can be found in Glasgow where jm architects were employed by developer Classical House to transform an 1820s Grade B-listed mansion in the city’s Linn Park. The property had fallen into such disrepair that the roof collapsed and the whole building was deemed unsafe. Rather than demolish, however, a feasibility study was commissioned to test the viability of conserving and converting the building for residential purposes. The result is a faithful restoration of the existing historical villa and an uncompromisingly modern timber extension to the rear.
The use of timber here has multiple functions: it forms a new mediation between existing building and landscape; it emphasises the distinction between new and old and makes no concession to the oft-required use of identical materials; and it provides a crisp, simple counterbalance to the heavy detailing and blond colour of the mansion’s sandstone construction.
This is more than just a simple domestic extension, however – the cleverly crafted larch-clad box in standard 150mm timber frame contains two discrete residential units whose windows are designed to maximise available natural light and frame the views of the park. It also doubles the number of flats in the project, ensuring the financial viability of the restoration.
Building onto traditional stone buildings doesn’t need to be to the side or rear only – it can also be above, and in such situations timber is frequently the obvious material, adding less weight to existing foundations.
With flooding a threat, the cedar-clad extension of Craigo Mill takes the building skywards
In many instances roof extensions end up being a compromise between planning restrictions and existing roof structures. Only rarely is the solution both effective and visually attractive. At Craigo Mill in Angus, however, flooding from the River Esk forced a more radical solution. Unable to avoid the situation recurring, the owners and their architect, Mark Walker, chose to reconfigure the two-storey house and make the ground floor as flood-proof as possible, while moving the main entrance to first floor level and accessing it with the introduction of a traditional Scottish fore-stair.
Cleverly, the bedrooms have been kept on this level to allow the new, western red cedar-clad top floor to contain an open- plan living area in which the roof structure is a visible part of the interior design as, while the structure is standard timber frame lined with plasterboard, the roof trusses have been left exposed. The western red cedar has been left untreated.
Aside from the enhanced views of the surrounding countryside from the new top floor, the owners now have the security of knowing the living accommodation has been raised above flood level. In a period when this problem is more and more prevalent throughout the UK, transformations such as this may well become more common.
More usually, however, the desire for increased living space is the critical determinant in extending a property. How much volume can be successfully added – or allowed – is often a moot point, and a late 1950s three-bed semi-detached former council house in Fernieside, Edinburgh has an extension that appears almost as large as itself yet, being within 26m2 limit for permitted development, avoided needing planning permission.
The uncompromising modern extension of the 19th century mansion in Linn Park
In transforming the property, the architect, Graphite Studio’s Simon Brims, not only designed a distinctive rear extension in standard timber frame, but also remodelled the interior and converted the attic to create a five-bed home, with an upper floor polycarbonate-lined ‘light box’ and external deck area.
It is this upper area that perhaps distinguishes the project from the usual single-storey addition: the glass box that was originally conceived for the first floor would have required an expensive – and heavy – steel support structure, so the notion of the glass box has instead been realised in timber. The polycarbonate light box is sheathed with narrower untreated oak boards spaced more widely than those used for the ground floor cladding to create an oriental lantern-like glow in the evenings. The adjacent roof terrace allows the owners to survey the extraordinary landscape scheme that covers the garden and the ‘contemplation’ hut – a kind of home office – that terminates the view.
The use of timber in house extensions is no longer an unusual phenomenon – more and more this type of project provides the testing ground for ideas that later emerge in larger buildings.
