Point cloud is a result of laser scanningIn March 2018 Trimetari Consulting LLC performed a measurement of the building of the Palace of Children’s Youth Creativity named after L.N. Maklakova in Kirishi, Russia by the method of ground-based laser scanning. Built in the Soviet era, in 1984, the Palace survived the nineties, stepped into the 21st century, but for all this time it was practically not updated. That is why the task of repairing the largest education center in Kirishi has become one of the top priorities for the city administration.

To carry out total building renovation in 2017, design and estimate documentation was developed and passed the expertise. The power supply, heating, ventilation, sewerage systems will be completely replaced in the building, internal interiors will be updated. It is planned to replace windows and doors, installing stained-glass windows, replacing the mechanical equipment of the stage, building theater and technological systems, replacing furniture and equipment. During the repair, the building’s security systems will be updated (fire-fighting system, security and alarm systems, etc.), telephone and local-computer networks. Among other things, it is necessary to mount a ventilated facade – rainscreen.

Cleaned point cloud can be used for design of the rainscreenRainscreen has a number of undeniable advantages, such as high thermal and sound insulation, reduced costs for heating, durability, weather resistance, a wide choice of facing materials. However, one of the main drawbacks of a ventilated facade is the difficulty of mounting on insufficiently flat walls. The unevenness of the walls can often lead to the need to use non-standard elements when installing a ventilated facade. Eliminate the negative impact of uneven walls helps the competent design of the rainscreen, taking into account both the actual location of the daylight openings, balconies and other elements of the facade, and unevenness, incl. deviation from the vertical. To perform such a project, ones need an accurate and detailed measurement of the building – the facade and the roof. The higher the detail and accuracy of the architectural measurement, the less errors will be contained in the design and the less problems will arise at the stage of installation of the facade. A good project will help to save money and in case of using expensive cladding – the correctly executed cutting of the facing material will allow to reduce the expense and will pay for the cost of measuring the building.

Laser scanning provides high detail and accuracy of the measurementsHighly detailed and high-precision measurement of the facade can also be attempted with traditional geodetic methods, for example, a total station, a tape measure and a plumb bob, but instrument errors and the human factor can negate all the advantages of this approach. Therefore, it is recommended to perform a measurement of the building using laser scanning. As a result of 3D scanning, a point cloud is obtained – a three-dimensional array of data that fixes the geometry of the facade with millimeter precision. When designing, you can use both a point cloud (in Autodesk products for example there is a direct support for a point cloud using RCP format), and an actual 3D model built on a point cloud.

3D models of facades, created with use of point cloudIn the case of the Palace of Children’s Creativity, the customer chose to work with the 3D model. The design goes faster, lower requirements for the computers used, the design process itself is simpler and more intuitive. To create the actual 3D model, a laser scanning was performed using the Leica ScanStation P40. From 60 stations about 1 billion measurements were performed over several hours of fieldwork. The mean-square error of mutual equalization was 0.003 m. A full point cloud was ready the next day. Later in a few days, a 3D model of the facades of the building in the format of Autodesk DWG was created on the point cloud. In accordance with the terms of reference, the model was divided into several layers, the ends of the slabs, sections of the facade made of concrete were made separately from the brickwork. The contours had a clearly worked out look, the model fixed all the unevenness of the walls.

3D model contains all unevenness and geometry of the facadeDesigning a rainscreen based on laser scanning will significantly reduce the costs during the installation phase, the hinged facade will last a long time, will have the claimed characteristics and have an excellent appearance with smooth surfaces. Completion of repair works of the Palace of Creativity is planned by August 2019, students and teachers will happily return to the renovated building.