I am looking at the potential to convert my attic to usable space. It is too low to qualify for human habitation (about 2m max height) but it occupies a large surface area in proportion to my very small semi-detached house (57sq m/614sq ft). I don’t want to engage a turn-key attic conversion company as I just want a basic, structurally sound open space with stairs and it would not be worth spending more than €10,000 for it, so I am thinking of doing it piecemeal starting with the steel. My attic has a simple trussed roof with concrete tiles on a single apex so I reckon a single steel would do. The width between the gable walls is about 4.7m. Would you be able to advise roughly how much a steel for this would cost, including structural engineer certificate?
The conversion of an attic is a great way to accomplish additional floor space, writes Noel Larkin. The cost is usually more manageable than an extension. The fact that you are working within the existing building envelope means that your roof and external walls are in place already and therefore more resources can be directed towards better finishes, improvements and the like. But converting an attic is always a balancing act. How useable will the additional space be? Will it be habitable? What space will be lost at first floor level to accommodate a new staircase to the attic? What is the additional cost of bringing the house into compliance with the building regulations in terms of means of escape and fire precautions?
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The provision of an additional floor increases fire risk and the building regulations require fairly substantial improvements to the original house as a result. Although the attic space will typically be put to habitable use, many people do the “Irish thing” and say the space is for storage use only and therefore avoid the necessity of improvement of the original house. This is both wrong and extremely short-sighted. The regulations are concerned with protection of life and they should be heeded.
Conversion of an attic is a specialised job and best left to the professionals. You mention that the roof in your house is a simple truss roof. Trusses, although simple in appearance, are quite complex in how they work. They operate on the principle of transferring weight of the roof coverings and applied loads, such as wind and snow, to the external walls.
If the truss is cut or altered, it will no longer work as designed. Weight can then be incorrectly transferred to the internal partitions or on to the upper floor ceilings. In my experience as a building surveyor one of the biggest issues we encounter, where we advise our clients to “look elsewhere”, is DIY attic conversions. Turning a blind eye to the intended use of an attic is one thing but if the structure has not been properly designed and the work not properly implemented there can be major consequences.
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My advice is to have an engineer assess your property and they will be able to give you specific information on how best to proceed and on the correct materials and methods to be used. If you want input in terms of design and location of a new staircase or internal layouts, a chartered building surveyor can also help.
When considering an attic conversion, I would advise against being penny wise and pound foolish.
Noel Larkin is a chartered building surveyor and a member of the Society of Chartered Surveyors Ireland (SCSI)
