Gross external area GEA
The area of a building can be measured in a number of different ways:
It is very important to be clear about which measure is being used, for example in property sales, planning applications, building regulations applications, lease negotiations, rating valuations and so on.
The UK government’s Valuation Office Agency (VOA) Code of measuring practice: definitions for rating purposes suggests that ‘gross external area’ refers to the whole area of a building taking each floor into account, including perimeter walls. This includes:
- Perimeter wall thickness and external projections.
- Areas occupied by internal walls (whether structural or not) and partitions.
- Columns, piers, chimney breasts, stairwells, lift wells and so on.
- Lift rooms, plant rooms, tank rooms, fuel stores, whether or not above roof level.
- Open-sided covered areas (should be stated separately).
Gross external area excludes:
- Open balconies.
- Open fire escapes.
- Open sided covered ways.
- Open vehicle parking areas, terraces and so on.
- Minor canopies
- Any area with a headroom of less than 1.5m (except under stairways).
- Any area under the control of service or other external authorities
It suggests that party walls should be measured to their centre lines.
The VOA Code of measuring practice is in general agreement with RICS Guidance Note, A guide for Property Professionals, 6th Edition Code of measuring practice 2007, other than, areas with a headroom of less than 1.5m which are excluded from the VOA measurement.
 Related articles on Designing Buildings Wiki
- Beneficial occupation.
- Case notes for rating valuation (Garton V Hunter).
- Choice of method for rating valuation.
- Contractor’s basis for rating valuation.
- Floor area ratio.
- Gross internal area.
- International Property Measurement Standards.
- Net internal area.
- Profits method of rating valuation.
- Rating valuation.
- Rental method of rating valuation.
- Statutory formulae for rating valuation.
- Total useful floor area.
Featured articles and news
High quality and high density homes - is it what we need or is it storing up trouble?
Government announces its intention to strengthen planning rules to protect music venues and neighbours.
National Audit Office reports that there is little evidence that PFI offers better value than other forms of contracting.
What is liquidation and how does it apply to contractors in the construction industry?
Scrutiny is placed on Carillion's controversial 2013 decision to extend subcontractor payment terms to 120 days.
RSHP unveil their involvement in a boundary crossing which will provide a new entry point into Hong Kong.
With PFI currently under the spotlight due to Carillion, this introductory article explains what they are.
Estimates suggest that up to 30,000 small firms could be at risk of non-payment as a result of Carillion's collapse.
Sir Oliver Letwin to lead an independent review into the delays in the delivery of housing.
As Carillion collapses, read our article explaining insolvency in the construction industry.
43,000 jobs at risk as Carillion declares insolvency.