Duncan Weir and Sarah Lamont on the wide-reaching implications of the revised building regulations, which come into force next spring to a mixed reception from the industry
16 December 2005
From April of next year, parts F and L of the revised Building Regulations will come into force. All buildings constructed after 6 April 2006 must adhere to the new legislation.
Part F regulates ventilation, providing new standards for ventilation of buildings which are regularly frequented by people, but not buildings, for example, which are solely used as warehouses or garages. Meanwhile, part L deals with the conservation of fuel and power.
There are several changes to the new part F. The old prescriptive legislation has been dropped for a performance-based approach; developers have the flexibility to choose how to meet standards. Provisions have been made to ventilate buildings having air permeability down to 3 m3 /h/m2 at 50 PA. The recommended air supply rate to offices rises from 8 l/s per person to 10 l/s per person.
More guidance is given for domestic mechanical and natural ventilation systems and for ventilation of basements in dwellings. Mandatory air pressure tests on new buildings will be introduced to help to find inefficiencies.
The revised part L incorporates parts of the European Energy Performance and Building Directive which must be fully implemented by December 2008.
The intention of this new Part L is threefold:
to limit heat loss through the fabric of the building, limit excessive solar gains and heat gains and limit losses from pipes, ducts and vessels used for space heating, space cooling and hot water storage
to provide energy efficient and properly commissioned fixed building services with effective controls
to provide to the owner sufficient information about the building and its building services in order that the building can then be operated and maintained in such a manner as to use no more fuel and power than is reasonable in the circumstances
New standard carbon emission calculation technologies will set upper limits for carbon dioxide emissions, allowing developers to choose the best solution, such as use of low and zero carbon (LZC) technologies like solar panels.
Under the Kyoto treaty, the UK must reduce its greenhouse gas emissions by 12.5 per cent (on 1990 levels) by 2012 and carbon dioxide by 20 per cent (on 1990 levels) by 2010. The new regulations are expected to save one million tonnes of carbon by the end of the decade, which is the equivalent of the emissions from over 1 million semi-detached homes.
Part L is split into four parts, each regulating a different type of building work:
L1A - work in new dwellings
L1B - work in existing dwellings
L2A - new buildings other than dwellings
L2B - work in existing non-dwellings
Under the new regulations, new homes are to better insulated and use more efficient heating systems such as condensing boilers. These changes will cut the average fuel bill in new homes by 40 per cent.
Part L1A focuses on living accommodation, but also applies to mixed use buildings that contain rooms for commercial use which could revert back to domestic use. Compliance with the new regulations is demonstrated by meeting the prescribed criteria.
Common areas of buildings containing multiple dwellings are not classified as dwellings and so, if heated, fall under L2A. If unheated they must still comply with the
U-value standards of part L1A.
New dwellings built with conservatories should be assessed as if the conservatory is not there. This means that the doors and walls between the dwelling and the conservatory must be constructed to the same standard as the rest of the external components. Conservatories under 30 sq m are currently exempt from the building regulations.
It is not only new homes that are to be regulated. Part L1B gives guidance on: extensions; creating a new dwelling through material change of use; material alterations ; controlled fitting; controlled service; and the provision or renovation of a thermal element.
Special considerations apply to buildings of special historic or architectural value but in these cases, the focus is on improvements which do not compromise the character of the site.
New commercial buildings such as offices also fall under the new regulations. Part L2A gives guidance on works comprising: new buildings other than dwellings; the first fit-out works in any building constructed to comply with the amendments; the building of extensions greater than 100 sq m and greater than 25 per cent of the gross floor area.
Special consideration is to be given to modular and/or portable buildings where the intended life is less than two years or more than
70 per cent of the parts for the external envelope is made before April of next year.
Although the revisions to Parts F and L have been widely commended by consumers who stand to reap the benefit of reduced bills, the construction industry has been less positive in its response. The revisions were originally set to be announced before the summer parliamentary recess, but did not actually come out until September 2005.
Industry bodies believe that this does not leave enough time for new systems to be implemented before the regulations come into force. Specialist software is being developed but this still leaves very little time for modification and training. While the systems provide great benefits, the impact upon small and medium-sized house builders seeking to comply will be high training and development costs.
One view is summed up by John Tebbit, industry affairs director at the Construction Products Association: "Projects will be delayed, people will be sued and it will be an unmitigated disaster. The only people to make any money off it will be the lawyers".
Duncan Weir and Sarah Lamont are partners at Bevan Brittan LLP