BUILDING REGS PART L – 2010 SEMINAR NOTES
• 2010 regs are a “flat 25%” improvement over 2006 regs.
• Party walls are now designed for heat loss as well as sound reduction.
• SAP calculations to be completed before building work starts and on
completion to ensure what has been designed and built match.
• Minimum number of LE light fittings increased from 25% to 75% with a
minimum luminous efficiency of 45 lamp lumins per circuit watt.
• The backstops have been improved over 2006 regs. Backstops are the
minimum u-values for building elements set out in the regs. Building to
the backstops will not meet the new target emission rate in Part L 2010.
• Accredited Construction Details – If dwellings are built using ACD’s, then
no adverse effects to the SAP calculations. Otherwise if non-accredited
details are used this will have a negative effect on the Dwelling Emission
Rate (DER) under SAP 2009.
• If an initial notice has been given before 1st October 2010, then 2006 regs
still apply. Work must also start on site before 1st October 2011.
• Accredited Construction Details are only suitable for standard house
designs. In most cases for non-standard details the DER value will be
• If using an ACD scheme the builder must demonstrate an appropriate
system of site inspection and hand this over for approval to the BCB – See
Approval Document L1A – Section 5.9 Thermal Bridges for further
• New compliance guides have been published:
Domestic Building Services Compliance Guide 2010 Edition.
• Minimum u-values for windows increased.
• General strengthening of replacement standards, ie. ‘A’ rated rather than
‘B’ rated boiler, ‘C’ rated rather than ‘ F’ rated windows.
• Extensions continue to use elemental approach but can use SAP/SBEM
for greater flexibility.
• Building Services Compliance Guides set minimum standards for new and
replacement services in existing buildings.
• Part L changes encourage greater levels of air tightness greater levels of
design ventilation will be required.
• To meet Part L, mechanical ventilation with heat recovery likely to become
BUILDING REGS PART F – 2010 SEMINAR NOTES
• Ventilation provisions now based on a design air permeability lighter than
or equal to 5m3/(h m2) at SOPa.
• PSU diameters increased to 125mm for all room types.
• Door undercut is now 10mm above floor finish of the finish and fitted or
20mm above floor boards or other surface if the floor finished is not fitted.
This applies to fire doors in three storey houses as well.
• In practice the as built air permeability is lighter than designed air
permeability designed ventilation is inadequate. Additional variable
ventilation allowed for at design stage which can be adjusted at testing
stage depending on the as built air permeability, ie. PSU.
• Where dwellings are to have a least 70% of the equivalent ventilation area
on a single façade, these properties must be designed as if they are single
façade dwellings, ie. High and low ventilation providing the total equivalent
ventilator area on that façade.
• Where mechanical ventilation systems are installed (intermittent or
continuous) air flow rates are to be measured on site and given to BCB.
• It is now required that building owners are given adequate information
about the ventilation systems.
BUILDING REGS PART J – 2010 SEMINAR NOTES
• Much of ADJ now redundant as it deals with inefficient appliances which
are effectively not permitted by ADL 2010.
• All new and replacement solid fuel appliances to have CO alarms.
• All chimneys/flues must be capable of inspection throughout their length.
• No flues through neighbouring property due to access problems.
BUILDING REGS PART G – 2010 SEMINAR NOTES
• Main new requirement is the introduction of a maximum water usage of
1251/person/day of wholesome water.
• Introduction of the water efficiency calculator for new dwellings.
• Regulation 17K – Water Efficiency of New Dwellings – a new regulation
that requires new dwellings to limit potential consumption of wholesome
water to 1251/person/day.
• Wholesome water must be provided to:
- any place where drinking water may be drawn off
- and washbasin or bidet provided in or adjacent to a room
containing sanitary conveniences
- washbasin, bidet, fixed bath and shower in a bathroom
- any sink in an area where food is prepared
• Provision of water of a suitable quality to a sanitary convenience fitted with
a flushing device. This can either be wholesome water or water of a
suitable quality having regards to the risks of health, ie. Reclaimed
greywater (water used for washing and bathing.
• Hot water outlet to fixed bath in a dwelling to be limited to 48º c by use of
an in-line blending valve or TMV (Thermostatic Mixing Valve).
• Further requirement for provisions of high temperature flushing for
pasteurisation of pipes where intermittent use is anticipated.
• Length of pipework between the valve and the outlet to be kept to a
minimum to avoid legionnaires disease.
• Dwellings and buildings containing one or more rooms for residential
purposes are required to be provided with a bathroom containing a wahs
basin and either a fixed bath or shower.
• A sink is required in any kitchen or place used for the preparation of food.
However, where a dishwasher is provided in a separate room that is not
the principal place for food preparation, there is no requirement for an
additional sink in that room.
• It is possible to use (Automatic Flow Limiting Valves) to reduce the flow
rate of taps (showers etc.) to comply with the water efficiency calculator.