Many years ago while working for a local authority, I was asked to assist with the development of regulations and standards for an emerging African country so it could improve its building stock. One of the main aspects of the brief that struck me was that existing buildings would be reviewed every ten years, and upgraded to any new relevant standard as necessary.
This has never been a requirement in the UK, although some people say that in light of recent events such as the Grenfell Tower fire we should adopt the idea in order that older buildings, constructed to former standards, can be improved to bring them in line with evolving requirements.
However, Building Regulation 4 demands that, when carrying out work to extend or alter an existing building, such a building should continue to comply with the relevant standards, 'or where it did not comply with any such requirement, is no more unsatisfactory in relation to that requirement than before the work was carried out'. This means when any work is carried out on an existing building, a building control officer should check to make sure it does not render that building non-compliant.
But how far should we go in making such an assessment? It all depends on what is proposed and what the effect of the work is on the existing building. On each occasion, an assessing officer must be clear about the proposals and ensure that the work does not lead to adverse effects on the building.
Let me give an example: a while ago an application was submitted to my employer to renovate an eight-storey office block. It had been built in the mid-1960s for a local authority education department and had recently been sold, with the new owners wanting to take down all partitions to make it open plan. This would triple the likely occupancy of the renovated building, but the existing staircase would be too narrow to accommodate all the occupants in the event that simultaneous evacuation was required, in contravention of Building Regulation B1 on means of escape.
So the proposals were discussed, and it was decided that the most appropriate solution was to look at phased evacuation. This meant that more fire protection was required on the staircase, while the alarm system was upgraded and the fire risk assessment revised. Further consultation was then undertaken with the fire authority, and all the details were passed to the new owners so that they could operate the building safely.
Another example is the application of Part L to existing buildings and the use of consequential improvements. The Grenfell Tower fire, for instance, has shown that applying insulation to the external fabric of a building may change its fire dynamics, and this must be taken into account.
Another consideration is where the building is of historical significance and proposed work may affect its performance. Historic England has a very good guide on how to apply Part L in these circumstances, and I would urge anyone involved with such buildings to consult this.
Bear in mind that these represent only a few possible impacts of work on existing buildings, and there are many others that can have a negative effect on their safe and efficient operation.
Wherever work is being carried out on an existing building, we must be vigilant to ensure that it does not jeopardise compliance with regulations or worsen existing defects.
Martin Conlon is the director of Assent Building Control firstname.lastname@example.org
Related competencies include: Building control inspections, Legal/regulatory compliance