An NLA (Net Lettable Area) survey applies the third method of measurement as described in the Property Council of Australia guidelines for floor space calculations. This method is used when determining tenancy areas in office buildings and office and/or business parks. The NLA of a building is the sum of its whole floor lettable areas.

Net lettable area surveys for floor space calculations

Our business was built on preparing Lettable Area Surveys and we have become the industry leader in this space.

Three fundamentals drove our start-up business to disrupt the survey industry over 20 years ago;

  1. To become the single source of interpretation and best practice of the Property Council of Australia Method of Measurement
  2. Use the latest technology in obtaining accurate field data.
  3. Present the findings in a transparent and easy to read format for all interested parties to understand in their own way.

Obtaining accurately calculated tenancy areas for Office Buildings and Office Business Parks, the survey uses the Property Council Method of Measurement known as Net Lettable Area.


It is important to note that this is a method and not a standard. So there is a lot of reliance on the expertise of the surveyor to best interpret and use the correct method keeping in mind the landlord and tenants’ best interest. The Realserve team has specialised in this space for over 20 years.


The net lettable area is calculated by measurements from the internal finished surfaces of permanent internal walls and the internal finished surfaces of dominant portions of the permanent outer building walls.


Freestanding columns and engaged columns are included in the NLA. Ducts, accessways and recessed door areas are excluded from the NLA. One clause we find that needs special mention is the exclusion of fire hose reel cupboards. The tenancy area is taken to the face of the cupboard if the FHR is located there, inside the tenancy.


Office floor zones where there is less than 1.5metre height clearance above the floor level need to be measured and recorded separately. Lift and smoke lobbies calculations are determined site specifically if they are part of a common area or if a bank of lifts face each other.

Net lettable Areas for a sub-divided floor do have a slight variance in calculation where walls or partitions adjoin public areas such as lobbies and corridors.


If you own, manage or lease an office building you will find a Net Lettable Area Survey most useful for;

  • Showing tenancy square metres on signboards and other marketing material.
  • Attaching to Lease Documentation.
  • Property Valuation reports.
  • Rental calculations.
  • Registering a Lease.

Our typical process

The property council believes the best practice approach to measuring floor space as part of a lease negotiation is as follows;

Step 1 – Agree on the methods to be used

Step 2 – Agree on the measurements obtained

Step 3 – Negotiate the rental rates

Our fieldwork and lettable are plan presentation is the best clarification of the method of measurement with your specific site. If your commercial portfolio spans Australia, you can have the peace of mind when negotiating rental calculations with incoming or existing tenants, knowing you have the correct area.

We utilise the latest surveying technology to capture our data then produce our surveys. Using the latest CAD software programs everything is captured and processed accurately to start producing survey plans. The equipment we use is state of the art, ranging from traditional total stations to 3D laser scanning or RPA (drone). We only use the latest software tools including AutoCAD & Revit.

Once our plans are drafted they go through an intensive Quality Assurance process via an independent audit to ensure that what we have captured is delivered to the highest levels of accuracy possible.

In summary;

  • Initial consultation to ensure we can meet your needs.
  • Agree on a scope of work.
  • A site visit is organised with one of our qualified technicians with the necessary data collection equipment.
  • All data is then processed via our team located in one of our offices around the Country.
  • All plans or drawings are then independently reviewed via our QA process.
  • All deliverables are then created for viewing in PDF, AutoCAD or Revit.
  • We also have the ability to create a 3D scan or virtual tour of your property to create a fully interactive view of a site.

Net Lettable Area Survey Plans

See some of our case studies