BUILD RIGHT
Tucking up
downlights
Manufacturers, suppliers, designers, electricians and insulation installers
should all know how to maintain the thermal envelope around downlights.
Do you?
By Stephen Sargent, BRANZ Technical Writer
I
nsulation is often installed with a
clearance distance around recessed
downlights. The effect of heat loss from
warm air rising into concealed ceiling
spaces is often seen as far less important
than possibly causing a deadly fire from
insulation abutting a light fitting.
If you want to improve your
thermal efficiency by not
having a gap between the
insulation and fitting, BRANZ
recommends using a CA or
RA fitting.
provided by manufacturers and designers
❚ if specified, fittings are sometimes
substituted for a similar looking fitting
during the supply/installation process.
Electricians must ensure compliance
What the requirements say
This thinking goes against the requirements
of the New Zealand Electrical Code of Practice
(NZECP) 54: 2001 which states under 2.6
Thermal Insulation: ‘Recessed luminaires and
any auxiliary equipment shall be constructed
and installed so as not to compromise the
thermal efficiency of buildings’.
It also isn’t supported in that, historically,
insulation products used in New Zealand
have not typically supported combustion.
The problem is further compounded
because:
❚ there is a lack of detail about lighting
available on the market and not all light
fittings have been tested to NZECP 54
❚ lights are often selected by the owners
and sometimes specified relatively late in
the construction process
An electrician is bound under the
requirements of their registration and selfcertification authorisation to ensure that
NZECP 54 is complied with. For details refer
to the Energy Safety Service website www.
ess.govt.nz under ‘Rules and reports’, ‘Acts
and regulations’, ‘Electricity Regulations 1997
bottom chord of ceiling trusses
of rafter
❚ insulation is usually installed at a
different time (by a different person) to
the light fittings
❚ the relationship between the New
Zealand Building Code (NZBC) Clause
E9 Electricity and NZECP 54: 2001 is
clearly defined, but misunderstood
ceiling insulation
(segment type)
plasterboard
❚ light fitting types have historically not
been required to be specified at the
time of building consent approval by the
Territorial Authority
❚ a wide variety of specialist and/or budget
generic NZECP 54 Closed
Abutted (CA) type recessed ceiling
downlight, complete with integral
transformer, allows insulation to be
fitted tightly to light cover
lights (both bulbs and fittings) are now
Figure 1: Optimum layout to ensure NZBC Clause H1 compliance.
24 BUILD October/November 2006
ceiling battens
and amendments’, and then specifically to
‘Regulations 69 Electrical safety and 69A
Electrical installations’.
Specify at consent stage
Downlights should be specified at the time
of building consent. The NZEPC 54 fitting
rating needs to be indicated to ensure that
the NZBC Clause H1 Energy efficiency is not
compromised when downlights are installed
in a ceiling.
NZECP 54 gives guidance on ‘the selection
of recessed luminaires and their installation
requirements to ensure that the integrity of the
building is maintained. This integrity includes
building elements, thermal, acoustic, fire and
moisture’.
If you see a gap between the insulation
and the fitting, and want to improve your
thermal efficiency, BRANZ recommends using
the correct fitting type. To allow close-butted
insulation, the light fitting must be rated as
either category Closed and Abutted (CA) or
Restricted and Abutted (RA) – refer to the
manufacturer’s installation instruction sheet.
Typically use only CA fittings above moist
areas like kitchens, laundries and bathrooms.
Some DIY allowed
The Acceptable Solution G9/AS1 allows
members of the public to carry out some
of their own electrical work. The Electricity
Act, Regulations and relevant Codes of
Practice are available on the Energy Safety
building element above fitting (floor, roof)
transformer T
H
S
I
insulation
ceiling lining
H = height clearance (HCB) to building element
Halogen fitting - 200 mm min.
Incandescent fitting - 50 mm min.
or to manufacturer’s specification
I = Thermal insulation clearance:
Halogen fitting - 200 mm min.
Incandescent fitting - 50 mm min.
or to manufacturer’s specification
(abutted, standard or specified)
T = Recommended transformer clear
from luminaire, to manufacturers’ instructions
S = Side clearance (SCB) to building element:
Halogen fitting - 200 mm min.
Incandescent fitting - 50 mm min.
or to manufacturer’s specification
Clearance specified in NZECP 54 for untested
light fittings in confined spaces.
Insulation would be compromised in this installation.
Figure 2: The clearances specified in NZECP 54 for
untested light fittings in confined spaces. Insulation
may be compromised in this installation.
Service’s website www.ess.govt.nz. A good
first reference for those considering altering
wiring, A guide to doing your own electrical
work safely and legally, is available on the
website under ‘Safety information’ then
‘Electrical safety’.
But remember, don’t remove the cover or do
any wiring work behind the meter board.
Electrical Workers Licensing Group
The Electrical Workers Licensing Group was transferred to the Department of
Building and Housing (DBH) on 1 September 2006.
The Group provides registration and
complaints assessment services to the
Electrical Workers Registration Board,
and was previously part of the Ministry of
Economic Development. It is responsible
for certifying the ongoing competency
of the country’s 38,000 electrical and
electronic workers. Nothing will change in
the way electrical and electronic workers
are registered. The same staff will be doing
the job and the Group’s contact details will
remain unchanged.
The transfer is part of a suite of
Government reforms to provide improved
and integrated services to the building
sector and the public, and to bring
occupational licensing in the sector under
one ‘roof’. Other occupations overseen
by the DBH include chartered engineers,
associate engineers and architects, as
well as the establishment of 13 licensed
building practitioner classes. The Plumbers,
Gasfitters and Drainlayers Registration Board
will transfer to the DBH in 2008.
BUILD October/November 2006
25