In April 2006 the Building Regulations were amended to include a section on Conservation of Energy and Fuel under Part L1B which was designed to compel homeowners to include insulation in walls, roofs and floors where existing insulation was nil or inadequate at such time as any renovation or repair work is carried out.

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The regulation concerning walls is that if an external wall has a U value – thermal efficiency – higher than 0.7 then insulation has to be used when removing, replacing or adding a layer to the wall unless a very good technical or economic reason makes this impossible to do. The target to try and achieve is 0.35 U value and an existing 9 inch solid wall is rated as 2.05 U value ie a 75% plus reduction in heat loss is being targeted.

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Therefore when replacing old render or pebbledash on the exterior of the wall or adding  a render for the first time a solid wall insulation system must be used at the same time . This can be external or internal but to comply with the Regulations internally is very disruptive and costly especially as the “whole of the wall ” must be covered with no thermal bridging allowed.

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Therefore it is far easier and ultimately cheaper to externally clad the wall from top to bottom in a layer of insulation before covering the insulation slabs in a weatherproof and maintenance free rendered or brick finish.

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These systems are all accredited and are checked and signed off by local Building Inspectors whilst the work is being carried out and the homeowner receives a Building Regs Completion Certificate at satisfactory completion of the work.

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Since April 2006 it has been a requirement of the homeowner when removing or adding a layer to an external wall that the need for insulation must be incorporated into the renovation work.

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Part L1B of the Regulations governs floors, roofs and external walls and sets out the standards that are to be reached in terms of insulation and reduced heat loss . In layman’s terms if you have solid walls or an uninsulated cavity wall you cannot simply re-render or pebbleadash an exterior wall without submitting a Building Notice to the  Building Control Dep’t of your local  Council.

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At first glance it seems that the rules do not apply if you are altering less than 25% of the property’s walls and many people believe this to be the case. In fact the Regulations state that you are only exempted if less than 25% of any single wall is being altered and not 25% of the total wall area across the whole house.

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A further misunderstanding is that the insulation must hit a U value of 0.35 to meet the rules. In fact this figure is only a target figure and a lower insulation level is perfectly acceptable if it is technically, functionally and economically impossible to hit the 0.35 target.

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In most retro fit cases to hit 0.35 U value will mean bringing the wall out by around 3 to 4 inches in depth and thereby having implications for roof line overhang, cill depths, soil pipe and boiler flue clearance etc . As a result of the technical and financial challenges faced in hitting the target the vast majority of external wall insulations to existing properties are of a ” best achievable”  insulation standard and perfectly acceptable to Building Control.

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The introduction of amended Building Regs in April 2006 was targeted at fuel and energy conservation to cut emissions and reduce heating bills. It places a legal responsibility on homeowners carrying out any form of renovation, renewal or alteration work on external walls in particular.

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The regulations state that where the U value of a wall is higher than 0.7 then insulation must be added to the wall to lower the current U value down to a target of 0.35 ie equivalent to a new build standard property. The regulations also state there must be total coverage of the full height and width of the wall to prevent any cold bridging and therefore damp issues.

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On solid walled properties this usually means external wall insulation will have to be fitted when rendering or re-rendering an outside wall. To meet the target figure of a 0.35 U value will usually mean an insulation depth of around 80mm plus the render.

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On a lot of properties however this depth of insulation is technically not feasible due to size of roof soffit, soil pipes or window cill depths. In such instances the regulations allow for a thinner insulation depth so long as the homeowner has done the best possible within the constraints of the building.

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The other stipulation is that the system used must be technically approved as a certified insulation system by the likes of the British Board of Agrement testing authority otherwise the Council Building Officer will not issue a satisfactory completion certificate.

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Multiguard offer a range of systems that all meet the Building Regs and we can offer you free unbiased advice as to which system will best suit your home and meet all the regulations as well as a possible grant towards the costs. Crucially, a correctly installed system that is compliant with the regulations will also increase your HIP Energy score and your home’s value when and if you decide to sell.

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When you are carrying out repairs, renovation or replacement coating to an external wall then the work falls under Building Regulations Document L Part L1B

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As a taster of this legislation the emphasis is on reducing carbon emissions and cutting energy useage by requiring the homeowner to incorporate some insulation into the new wall coating. The Regs give set criteria that are to be achieved subject to certain caveats and Councils are increasingly vigilant in enforcing this legal requirement.

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The penalties for failing to observe the rules and regulations are very severe and can have a dramatic effect on anyone selling their home who has had some form of external render or coating either applied or renewed since April 2006. Such work needs to have a Building Control Approval Certificate to comply and if one has not been applied for then the work will very likely have to be re-done using an insulation system.

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Unfortunately for unsuspecting homeowners the onus is not on the building contractor to ensure compliance and the financial penalties are levied upon the homeowner and not the builder. For this reason alone please check to ensure you do not fall foul of the rules through no fault of your own

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For advice on the implications of Document L and how to ensure compliance please call us now on 01908 516366