00-08-2023
ADMO
Method of
Measurement
Problem Statement:
Gross Floor Area is a key indicator of project cost. We
use the term differently across the organisation
leading to differences in measurement and differences
in project costs.
Aim:
Align the way we use common terminology
and improve cost certainty through the way
we measure our projects
Method of Measurement: NZIQS (New Institute of Quantity Surveyors)
Standard definitions
• Net Area or UFA: Useable Floor Area, measured inside wall to inside wall. The space
needed for function as a room with beds, tables, in-room circulation, etc.
• GFA*: Gross Floor Area, the total ‘plan’ area including all building elements
measured to outside face of wall, as outlined by NZIQS
• Net/Gross Ratio: An efficiency factor used to determine how well a building stacks
up commercially and takes into account the difference between UFA & GFA
Other definitions
• KO GFA* or GIA: Gross Internal Area or the interior area to the inside face of
the exterior wall. Used to determine planning in various designs.
*note common terminology
Area Briefing Requirements: Nga Paerewa Hoahoa Whare - Design Requirements
Ngà Paerewa Hoahoa Whare Design Requirements
outlines the requirements for minimum areas for
our housing.
Table B2.1-1 states the following minimum Gross
Floor Areas [or GFA]
There are other area targets within our standards such
as the combined spaces for Living-Kitchen-Dining and
individual spaces for rooms such as bedrooms. These
are included as part of the same “GFA table” however
we believe the intent of these area requirements are
related to Net or Usable Floor Area [or UFA]
Area Comparisons: UFA, GFA, Circulation & Travel & Engineering
This figure represents the
area used by wall
thicknesses and circulation
Target GFA / Actual GFA
Area Plans: Usable Floor Area / Gross Floor Area / Gross Internal Area
Net UFA: 68.8sqm
GFA: 84.6 sqm
GIA (or KO GFA): 74.5 sqm
+/- 10%
Suggest actions:
Actions
Detail
Area Requirements
Ensure our Design Requirements are clear
for external consultants to interpret
•
Include terminology definitions that
align with NZIQS Method of
Measurement
Include worked example
Review format and
terminology used in table B2.1-1
•
•
•
Net Area
Total Net Area
Gross
•
•
Ensure our Design Consultants provide
appropriate information to Design Quality
for review and Project QS for Costing
•
Resource Consent & Building Consent
•
•
•
Net Area
Total Net Area
Gross:
• RC: that includes an allowance of
150mm exterior walls
• BC: as measured to exterior face
of cladding
Create benchmarking to enable Design
Quality to assess planning efficiencies
•
•
1-2 storey homes
3+ apartments
•
Net to Gross Ratios
ADMO Architecture Team
Sarah Hayden
Senior Architect – Design Library Programme
Sarah.Hayden@kaingaora.govt.nz