Roof plans are easy to produce. However, they’re not the easiest to survey as they are restricted depending on the location of the property.
This guide is part of our client’s guide to Measured Building Survey.
For example, if the property is above 2-3 storeys or if you are in central London where the height of the building is longer than the width of the road, it will be difficult for the surveyor to get all the details of the roof from the other side of the road.
If you can’t see the top of the roof from standing across the street that means will be a lot harder for the surveyor to do the same and produced the roof plans.
However, there are options to allow you to get the roof plans if you need the information. The most costly need the restricted option is to use a drone survey the roof of the property. There may be a slight increase in cost and time on site due to the methodology used.
There are currently Five methods that allow for a successful rooftop survey.
#1 Drone Survey
What is it?
A drone survey is a survey undertaken by a flying drone, most of the good drone surveys are plane type instead of helicopter/quadcopter type.
Here is an example of how it looks like
They use LIDAR technology to capture and position of your roof and the neighbouring properties.
Once the surveys are done the surveyor will try to match the point cloud data to their survey using a total station or other methods. This is ideal for very hard to reach roof and difficult areas. This methodology is mostly used for a large-scale topographical survey.
- Can survey the hard to reach areas
- The survey can be done in 1-2 hours compares to other methods
- Captures a lot more information than a total station
- The architect can view the roof in their browser (but it will be in Black & White)
- Costly – usually cost between £500-£800/day in addition to the measured survey
- License and permit required – they are quite restricted no-fly zones in central London and other areas that does not allow drone to fly. you may also need additional permissions surveying other people’s property
- Depending on the equipment the quality of the data can have an accuracy of 10-30mm
#2 Scaffold Method
What is it?
The scaffold can be erected around a building to allow the surveyor to survey detailed work. This is usually done for tall heritage building as they will need to survey all the features in high detail.
once erected the survey can survey the whole building, and can use the same scaffold for any repair works to your property.
- It allows for high detailed surveys of your roof and elevation of the property
- High accuracy and safe
- It can be costly and time consuming to erect, hire and dismantle the scaffold.
- You will need the council’s permit to raise the scaffold
#3 Access across neighbouring property (both sides)
What is it?
Usually, the roof of your property can be accessed or viewed from your neighbour’s property. This may mean that the survey will need to set up their instruments in the property opposite yours and as well as to the back. However, some buildings in central London may not have any facing windows the back of your property.
- Cheap and easy to survey
- Quick and accurate
- Cannot survey complex roof structures
- Limited to the view of the neighbouring property’s window.
- Access will need to be arranged
#4 Platforms and lifts
What is it?
The surveyor can also use platforms and lifts to reach the rooftop. This allows them to survey the property from the road and they can reach quite high safely. The surveyor will go on to the platform with their equipment and survey the roof.
It is usually the size of a car where there will be an extension that goes all the way up to the rooftop.
- Quick and easy to survey the rooftop
- Safe to use
- Costly to hire the equipment (platform and lift)
- Requires road closure/parking permit
- Requires training to use
- Cannot be placed on the back of the property on terraced buildings
- Takes a lot of time to set up the equipment
#5 Telescopic mast
What is it?
A telescopic mast is a specialist equipment for a 3-D scanner; it allows for the surveyor to survey the roof safely from the ground. It will produce the same data as a drone survey but with a higher accuracy.
The equipment will be lifted all the way to the top of the roof, and the instrument picks up all the points required.
- Very easy to setup
- Can reach up to 10m without
- Survey in less than 30min
- The architect can easily view the roof using a web browser
- Captures the data in colour
- Can cost £800 in addition to properties above 15m, (at icelabz we provide it freely up to 13-15m)
- May require permit for above 15m
- The scan may need to be done twice if there are high winds
The Roof plan is usually required for:
- Loft extensions
- Home Extensions which affects the outline of the property (usually two storey extensions)