Understanding building science is more important than ever when working with an old building envelope. There are differing opinions about which insulation is best for each type of wall, whether or not you should replace windows (which have notoriously long payback periods), if a building should be allowed to “breathe,” or if it should be sealed up tight.
There is a lot of contradictory information out there, so the best answer is: it depends.
Since each building is unique, rules of thumb can be dangerous. There are many things we need to keep in mind during renovations, including traditional building materials vs. composite products, documentation of existing conditions, what technology is best for our project, the use of sustainable building methods, and how to preserve as much of the materials as possible.
When it comes to the last point— preserving as much as possible— there is no better technology to get the job done than 3D laser scanning.
Traditional Building Materials vs. Composite Products
The evolution from traditional building materials to more complex composite products means that we have a stock of buildings containing materials that are not easily dismantled, reused, or recycled. This means that in order to perform a renovation, we have to keep everything exactly where it is.
Keeping material in place—and supplementing it with insulation or air sealing techniques—can sometimes be a better and more cost-effective option than removing or replacing it. By using a 3D laser scanner, you can capture the existing conditions of a building, including all of the details of the materials, and take it back to the office to evaluate whether or not you should replace or renovate.
Accurate Documentation Is Critical
Field verification of an existing building is, as every Architect and Designer knows, incredibly time-consuming with huge potential for inaccuracies. Technology has made it easier and more precise, and importing all of that data directly into a BIM software – like linking Revit via Realworks – can save time, but it can also capture the intricacies and details of older structures.
Below is an example.
Here is an example of what can be captured with 3D laser scanning. When using a high-quality scanner such as the TX6 Laser Scanner, it’s sometimes hard to tell the difference between photographs and scans.
The scanner generates data that is used to create what is called a point cloud.
The data can be imported into just about any 3D drawing program and is used to create the basis for a 3D model or construction drawing set. It will pick up on if the floor is uneven/sloping or if walls are out of plumb and not square. With scanning, one can take extremely precise measurements and create 3D mesh models of a building facade.
Below is an example of what you can see when using a viewing software. In this case, the individual used the Realworks Free Viewer.
These are things that may not be obvious to the observer at the time, but becomes clear when you allow the software to analyze the point cloud data.
For large complex buildings, such as the Northland Avenue redevelopment in Buffalo, NY, this was the best option to capture the immense size and variations in the construction of a sprawling, historic industrial complex made up of attached buildings dating from 1912 to 1981. Using a drone allowed the design team to better understand the varying rooflines and materials, and to document historic clerestory windows and roof monitors.
Using 3D Laser Scanning to Capture Reality
The ability to photograph a space simultaneously with data capture provides a complete record of the building that is invaluable when developing a renovation strategy. For historic buildings, capturing the finest details of the trim or window casings with a high degree of accuracy makes this an invaluable tool, and one that is in increasing use as the cost of the technology begins to come down.
It is still relatively expensive for a small firm or sole proprietor to purchase scanning equipment, but it could save money in the long run if a project requires a 3D model. But there are some less expensive options to consider as well. Outsourcing scanning or 3D modeling work may be a better option for new users or small firms who don’t necessarily have time to learn.
Using Scanning for Green Renovations Shouldn’t Be Ignored
The emphasis on ‘greening’ what we already have reflects a growing realization that, as we get better at making new green buildings, they are still going to be outnumbered by the much larger stock of existing structures which need attention. Green renovations are a huge and growing market. The USGBC recognizes that and continues to improve its LEED rating systems to better address the needs of existing buildings and to value their reuse. LEED Version 4.1 will be interesting to watch as each individual rating system rolls out this year, beginning with the one for existing buildings.
More good news for existing buildings is showing up in the market data. The renovation market kept growing through the economic crisis between 2008 to 2012, with green renovations outnumbering conventional. In addition, Environmental Building News reported in 2011 that the green building market remained stable, forcing designers and developers alike to rethink their focus. They also noted that McGraw-Hill’s Green Outlook 2011 found that new green construction had increased by about 50% between 2008 and 2010.
As the economy— and the construction industry— continues to recover, that growth in green renovations is continuing. Energy-focused retrofits are on the rise, and adaptive reuse projects are becoming a bigger focus. Building owners were driven to invest in what they already had, and many discovered that renovating green isn’t so difficult after all.
This is all the more reason to add 3D laser scanning to your toolbox. As renovations become more and more common, construction firms will need to find new ways of handling the existing building envelope. By jumping in and being the firm or individual that learns the technology first, you’ll be positioned well above the competition in no time.