What is a Detail & Contour Survey?
- Scott Bowden
- Apr 21, 2018
- 6 min read
Updated: Feb 10
So your architect or building designer has said you need a survey to start or progress the design of your building project. We answer your most common questions below.
What is a Detail Survey
Also known as a Site Features Survey, this is a 2D top view drawing that shows various man made and natural features of a property sit in position and elevation (height) and importantly overlays the property boundaries as accurately as possible for context.
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It differs from a title plan drawing that shows the legal property area, and an Identification Survey, which has only horizontal (x & y) content - Typically lodged to an authority to demonstrate how a specific building, fence or structure(s) in question relates to a property boundary.
On the most typical of renovation/extension projects, viewing this drawing is how we understand the size and position of your house relative to the property itself, and/or how we understand the topography and natural features.
In cases where the land is notably sloping, we will request that contours are shown (in addition to the spot levels) so that the reader can quickly understand the lay of the land initially and when we prepare our site plans and 3D models also. That's when its also called a Detail & Contour Survey.
Importantly, as well as being published in PDF, the drawing file is shared in DWG, which is digital formatted file that allows us to import it into our design software for unrivaled accuracy.
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Do I need a Detail Survey?
If you are serious about your project yes. Plus if you're building anywhere close to a boundary (relative to your Zoning) council will expect a copy.
BYO Floor Plan can keep its fees competitive relative to our skillset thanks thanks to our streamlined and methodical design service that gathers all the important information as early as possible to avoid rework.
Without a Detail Survey, we would essentially be designing blind, just hoping that our concept will work technically. Regardless of if our estimations were close to the mark, we'd then have to adjust all our dimensions to suit the exact parameters when we eventually get the survey - which would cost you in additional hourly fees and potential delays.
What is a Detail Survey used for by design professionals?
When designing a custom building, it will eventually existing beyond the paper and computer by being built amongst a landscape, cleared pad, near another building(s) or some combination of all these. To get accurate information about these items in 3 dimensions we need a detail survey. The 5 most critical categories of information to us are:
The ground's topography, captured by many isolated points (AKA spot levels), that give appear accurately on the drawing, but also have a nominated height. Depending on the project we will input the actual spot levels taken by the surveyor, or use contours for large open areas, or some combination of both
Building footprints, and sometimes roof lines, show us the overall size and position of the buildings, along with any skew that is almost impossible to identify by any other means. When designing an extension or addition, this is critical and allows us to crosscheck our own measurements.
The invisible true boundary lines are later overlaid in the computer which give all the other data context, and allow your designer to control the extent and size of their design either within the boundary or at a specific setback from it. You may be surprised to find out your fence or even a neighbour's carport is not necessarily where it should be.
Many other important site features are also captured such as roads, kerbs, driveways, retaining walls, swimming pools, sheds, water tanks, trees and dams, but depending on your project we will guide the surveyor to only spend time capturing an area of the property that is relevant.
Sometimes we'd like additional information outside of your property and more that just the road in front. See the below topic on Additional Scope
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Who pays the surveyor:
Typically, you as the end client, but this means you get a low price (no middleman fees).
However, our optional Consultant Concierge service takes away the need for you to review quotes, engage third parties and pay their invoices, as we would hire them as our subcontractors, just like a builder hires and manages a plumber or electrician. Unlike most building designers, our SC2 license category with the QBCC allows us the revenue headroom to do this.
It is even rare for most architectural firms pay for the surveyor's fees as it increases their liability and they are often more aligned with the academic community rather than contractor's in the field.
Does BYO Floor Plan get a kickback or commission:
No. We just want to see your project in safe hands, and don't expect you to know a contact in each of the preconstruction consultant categories.
How long does it take:
Typically 2 - 4 weeks. Midway through, the surveyor will do their fieldwork, with their service concluding when they email their drawing files.
Sometimes a surveyor will not release their DWG file (that we need) until their invoice has been paid - using the PDF as proof of their completed work.
When will the surveyor come out?
They will arrange this with your directly Typically within 1-2 weeks.
However, if you have engaged our Consultant Concierge service, we will coordinate this with you.
Do I need to be home?
If we are proposing an addition to your existing building, then a brief internal access will be required.
The surveyor will need to measure the internal floor at the key entries to home to confirm their heights relative to the ground levels outside. In the case of a knockdown rebuild in a flood prone area, we like to have the original internal floor level on record.
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How long will the surveyor be at my property:
3-7 hours for most urban properties, depending on how big the land is and how many features and structures it has.
Larger rural properties can take multiple days, especially if there are many built structures and relevant hardscaping works on the site.
Will the surveyor peg out my boundaries:
Typically not yet. While they are capable of this, it’s substantially more technical work and not needed in the design process, so we don’t request this of them - unless we have agreed otherwise for a specific reason.
However owner builders often will to avoid paying the surveyor to come back out during construction.
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Will the Builder use the surveyor:
Yes, if your project has a freestanding structure and/or an addition close to the boundary, it’s likely that your engaged builder will hire this surveyor to come back out and assist with locating the footprint or a couple of corners of the designed building to ensure its correctly positioned. They’re building contract typically cover this cost, to reduce your upfront (pre finance) expenses.
What is Reduced or Additional Scope?
Sometimes, a small project allows us to reduce area and/or scope of what is surveyed - to save you money. For example building an extension to the rear of a house means we don't need to know much about how the property interfaces with the front road, or vise versa for a front addition, we might not need to know anything about a backyard. We will typically always capture the whole house footprint though.
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On large rural properties, we might not need to know much about the fields steep banks and other areas that are well clear of the planned building site. We will just have the localised content shown within the overall property map
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Many times however, we recommend our clients increase the scope to include specific features of neighbouring properties, as it will help us design for privacy and prove this to council when we request relaxations to build closer to the boundary line.
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Also, quite often in built-up areas, our design proposals will be close to sewer and storm water infrastructure that is underground and has very stringent regulations around clearances to buildings. In this case we have the surveyor or their specialist contractor locate the size, depth and locations of these items so we can design structures as close as possible to maximise the ROI for our clients. Later in the project we and the structural engineers will use the depth measurements to propose foundations that are safe but much closer than is normally permitted.
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What is a Point Cloud:
On rare occasions, such as doing a fit out to a large building or complex commercial extension, we will arrange ahead of time with the surveyor for them to measure the relevant are with specialty equipment that generates a digital point clouds, for an incredibly detailed 3D file export.
Please note
The above is a general information only. Feel free to contact us or a surveyor for more detailed and specific information.
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