Measurement Flashcards
What is the difference between NIA, GIA and GEA?
NIA - the USABLE AREA of a building measured to the INTERNAL FACE OF PERIMETER WALLS of each floor level
Used for: valuation and marketing / rating of shop and supermarkets, offices and business use
GIA - the AREA of a building measured to the INTERNAL FACE OF PERIMETER WALLS of each floor level
Used for: build costs estimates, marketing and valuation of industrial buildings
NSA - the GIA of a new or existing residential dwelling, subject inclusion and exclusion conditions
Used for: marketing and valuation of residential property, new homes
GEA - the area of building measured EXTERNALLY at each floor level.
Used for: Council tax bandings of housing and bungalows. Build costs for residential insurance purposes
EFA - the usable area of the rooms within a building measured to the internal face of the walls including those rooms
Used for: council tax banding of flats and maisonettes
What is NIA and when would it be used?
Net internal area
The USABLE AREA of building measured to the INTERNAL FACE OF PERIMETER WALLS at each floor level.
Includes:
Notional Lift lobbies and fire corridors
Kitchens
Build in cupboards occupying usable area
Excludes:
Columns
COMMON aria & entrance halls, landing balconies, corridors
Lift & plant rooms
Vehicle parking areas
Shared corridors
Used for
- valuation and marketing of shop and supermarkets, offices and business uses
- ratings for shop and supermarkets, offices and business uses
What is GIA and when would it be used?
Gross internal area
The AREA of building measured to the INTERNAL FACE OF PERIMETER WALLS at each floor level.
Includes:
Columns
Atria & entrance halls with clear heights
Lift rooms
Garages / loading bays
Excludes:
Perimeter wall thicknesses and external projections
External open sided balconies, covered ways, fire escapes
Canopies
Void over or under structural, raked or stepped floors
Greenhouses
Used for:
- Build cost estimates
- Marketing and valuation of industrial buildings
What is GEA and when would it be used?
Gross external area
The area of building measured EXTERNALLY at each floor level.
Includes:
Perimeter wall thicknesses and external projections, garages, internal balconies
Excludes:
External open sided balconies, covered ways, fire escapes
Canopies
Open vehicle parking areas and roof terraces
Greenhouses
Used for:
- Council tax bandings of housing and bungalows
- Build costs for residential insurance purposes
What are commonly used scales?
Room 1:50
Buildings 1:100
Location / street plan 1:1250
Location plan 1:2500 (larger sites)
Road / walking map 1:5000
Can you give some examples of tools used to measure sites and property?
Measuring property: tape, rod and laser device
Measuring land: trundle wheel
How does a trundle wheel work and what are the pros and cons?
Trundle Wheel
+ves: easy to use, portability, cost-effective compared to more advanced measuring tools, no power requirements, suitable for short distances
-ves: Limited Accuracy (affected by wheel wear terrain irregularities, and user errors). Not Ideal for Complex Surfaces and adverse weather conditions.
Cumbersome for Long Distances
Subject to Human Error
Suitable for simple and relatively short-distance land measurements, especially in situations where precision requirements are not as critical.
However, for more complex projects or when high accuracy is essential, other advanced measuring tools like laser distance measurers, total stations, or GPS systems may be more appropriate despite their higher cost and complexity.
Can you give some examples of tools used to measure physicals property and advantages and disadvantages of each?
Tape Measure
+ves: cost effective, simple to use, portable
-ves: Limited Length. accuracy
Laser Distance Measurer
+ves: High Accuracy, Quick, Can Measure Hard-to-Reach Areas:
-ves: Cost, Limited Range (especially in bright sunlight), Battery Dependency
Rod: a physical tool used to measure distances on the ground. It is typically a straight, rigid rod marked with length increments (e.g., feet or meters).
+ves: cost effective, simple to use, portable, clear markings, weather resistant
-ves: Limited Length. accuracy
What is a plot ratio?
Plot ratio = total floor area of a building (or buildings) / the total area of the plot of land on which the building(s) are located.
critical parameter planning and development to manage the density and scale of development within a given area.
What measurements need to be taken when measuring land using software?
- Check boundaries of site on an OS Plan / Land Registry Title document prior to calculating the site area
- Ensure the the distance is collaborated accurately to the scale bar
How do you physically measure a site?
- Identify boundary markers - that define the boundaries of the land parcel
- Set up equipment
- Conduct distance measurements
- Record data (field note book)
- Calculate areas / boundaries
What is the purpose of separation distances?
To ensure adequate space between buildings to address issues such as Daylight / sunlight (adequate light)
Privacy (avoid overlooking)
Fire safety and access
Ventilation
Specific requirements vary depending on:
Type of development
Location, and
Surrounding context
New Residential Developments:
typical separation distances 18-21m between habitable rooms (e.g., living rooms, bedrooms) of adjacent properties to maintain privacy and daylight access.
Commercial and Mixed-Use Developments: Separation distances for non-residential buildings may vary based on specific requirements related to fire safety, ventilation, and building access.
Comply with London Plan / LPA
Discuss at pre-app
What are the accuracy requirements for buildings?
What measurement standards / documents should be adhered to?
For OFFICES and RESIDENTIAL BUILDINGS RICS M+F should use IPMS. If not using IPMS reason for departure must be stated.
Code of Measuring Practice (2015) applies to all building classes except offices and residential buildings.
What is the basis for measurement in residential valuations?
There is no single accepted practice for measurement of residential property for valuation purposes. Typically NSA. State in valuation
What is NSA and when is it used?
Net Sales Area
the GIA of a new or existing residential dwelling, subject inclusion and exclusion conditions
Includes:
Basements
Mezzanines
Galleries
Hallways
Excludes:
Garages
Conservatories
Greenhouses
External open side balconies
Terraces
Areas with less than 1.5m where the dwelling does not have usable space vertically
Used for valuation and marketing of residential developments, particularly in new developments
What is effective floor area and what is it used for?
the usable area of the rooms within a building measured to the internal face of the walls including those rooms
Includes:
Living, dining, bedrooms, kitchens
Areas occupied with fitted cupboard in the room
Excludes
Bathrooms, showers, toilets
Stairwells, lifts, landings balconies
Corridors
Used for:
Council tax banding of flats and maisonettes
What are the IMPS (creator / purpose / application)?
Created by a group of over 80 professionals to implement international standards for measuring property.
Purpose: establishes a CONSISTENT MEOTHODOLOGY for measuring buildings around the WORLD.
IPMS All Buildings is applicable to ALL TYPES of Buildings independent of their use or their occupation.
When was the IMPS published?
IPMS All Buildings (15th Jan 2023) supersedes all previously published IPMSC standards for individual asset classes by utilising the concepts and objectives contained in those specific versions of IPMS into one harmonised standard.
What is the structure of the IMPS?
IPMS are divided into three (3) fundamentally different grouping:
1) IPMS 1 and IPMS 2 are EXTERNAL & INTERNAL measurements respectively for the WHOLE or PART of a Building.
2) IPMS 3.1 and IPMS 3.2 are EXTERNAL & INTERNAL measurements respectively required for EXCLUSIVE OCCUPATION.
3) IPMS 4.1 and IPMS 4.2 are INTERNAL MEASUREMENTS required for SELECTED AREAS respectively including Internal Walls and Columns and excluding External Walls and Column
What are the components of buildings?
IMPS All Buildings set out the different components within buildings (A-H)
E.g.
Component Area A - columns, walls and notional boundaries
Component D - Sanitary areas
How would you use and report on the IMPS?
Use:
1. Identify the purpose of the measurement
2. Select the appropriate IPMS for the purpose
3. Apply measurement practice for selected IPMS
Report:
Use of building or part of building
IMPS used
method and tools used
unit of measurement
date of measurement
if it has been verified
What are the negative impacts of using the wrong measurements?
- Safety hazards - compromise stability of buildings & infrastructure
- Cost overruns - design errors, material waste, timelines - need to be fixed
- Legal and compliance issues
- Bid - wrong land values costs
How do you mitigate risk of interpreting measurements incorrectly?
- Quality assurance
- Validation and verification
- Training and education
- Clear documentation
- Peer review
