Within a historic district, the contributing properties (which means all of the properties that are considered historic within the district) can’t be torn down. They can be restored. They can be given additions that are in keeping with their character. But they cannot be razed unless they have been found to be unsafe and a danger to anyone who might enter them.
There are some substantial environmental benefits to this policy. Less waste will be tossed into the landfill, fewer new resources will need to be harvested, and the substantial amounts of energy poured into processing new materials and using them to build a new house will be conserved.
Fewer Houses Thrown Away
At least 16% of what is currently being thrown into the Larimer County landfill from Fort Collins is construction waste. Statewide the estimate is even higher at 35%. It’s possible to estimate how much debris is being created by the demolition of one house by using a demolition calculator (often used by property owners and developers to estimate how many dumpsters will be needed and therefore the disposal costs associated with demolition). Scraping a 1,000 square foot house (which is close to the average of size of many Old Town homes) creates approximately 135 cubic yards of waste, or three and a half dumpsters worth. A 2,000 square foot house generates 270 cubic yards (or 6.75 dumpsters worth). (Hometown Demolition)
When buildings are demolished, large quantities of materials are generated. The entire weight of a building, including the concrete foundations, driveways, patios, etc., may be generated as C&D [construction & demolition] materials when a building is demolished. On a per building basis, demolition waste quantities are often 20 to 30 times as much as C&D materials generated during construction. – EPA document (page 10)
With the Larimer County Landfill estimated to be full by 2025, reducing the amount of waste added could extend the life of the site. Reducing the levels of waste also reduces the amount of methane and other greenhouse gas byproducts created by the landfill.
And learning to live within the current envelope of the house, or retaining the original house and adding a sensitive addition in the rear, basement, or attic, can also reduce the amount of construction waste generated, even when the house is remodeled to make it better suited for the property owners.
Existing houses have been made from materials that were harvested, processed and hauled to their current location. Older houses are often made from local materials due to the difficulty and expense involved in transporting building materials in the late 1800s and early 1900s (although in 1877, when the train first made its way through Fort Collins along Mason street, those with money were able to bring materials in from further distances). All of the energy used in harvesting, processing, hauling and installing is now embodied in the materials that make up the older home.
Razing the house and throwing it away means that all of that embodied energy is lost and must be replaced with new materials which will have to be harvested, processed, hauled and installed. And given that many building materials come from as far away as Asia, the energy expended can be quite substantial, even when the product, like bamboo, is advertised as a “Green” building material.
The issue of embodied energy is, at its heart, a matter of life cycle. Older buildings were made with long lasting materials in large part because cheaper synthetic options simply didn’t exist at the time. Though some parts of older houses may rot after decades of exposure to the elements, it is more environmentally friendly to replace the damaged materials and keep the rest of the existing materials well maintained rather than ripping out good and bad alike and replacing with a newer product, often with a much shorter estimated life cycle than what was replaced.
When most people consider whether it is better to keep or replace an older house, operational energy is often the only aspect of energy savings that they consider. Older houses that have not been well maintained may have gaps around windows making the house drafty. But more often than not, these problems can be fairly easily, and inexpensively, fixed with a little TLC and regular maintenance.
Remember that older homes were built before air conditioning existed for residential purposes and before heating systems had been tweaked for efficiency. So buildings were intentionally constructed to be energy efficient since there was no HVAC to rely on.
Deep front porches are a means of letting the sun in during the winter (when the angle of the sun is lower) but keeping it out in summer (when the angle is higher up). Lathe and plaster, as well as double or triple wide brick walls, act like energy sinks, taking a long time to heat up on hot days, which helps the interior of the house to stay cooler, and releasing that heat slowly through the night, when Colorado nights are cooler. In winter, these materials help retain heat inside the house.
And perhaps the biggest reason why older homes are more energy efficient than newer ones? They’re smaller.
“U.S. homes have become considerably more energy-efficient over the past four decades, according to government data. But homes also are a lot bigger than they used to be, and their growing girth wipes out nearly all the efficiency gains.” – Pew Research Center
Differences in Expectations
There are also differences in expectations regarding energy use. In suburban style developments there is an expectation that streets will be well lit, roads will curve, and sidewalks may or may not exist. Older neighborhoods that were developed with more of an urban layout come with an expectation that amenities such as grocery stores, banks and schools will be within walking distance. Sidewalks are often set back from the street with a tree lawn that improves the pedestrian experience and sense of safety. And minimal lighting is not only OK, but sometimes even preferred by residents.
A well maintained older home can be just as energy efficient as a new house, but when demolition and construction is taken into account, reusing an older house is far and away the better choice for the environment.