Designing for Hurricanes
The National Oceanic and Atmospheric Association’s Climate Prediction Center (NOAA’s CPC) is predicting an “above normal” hurricane season with 11 to 17 named storms, 5 to 9 hurricanes and 2 to 4 major hurricanes over category three. The historic method of learning about building performance is through experiencing hurricanes such as Matthew and Irma in 2016 and 2017, respectively. The better, less risky way is through research.
The nonprofit Insurance Institute for Business & Home Safety (IBHS) has a research center in Chester County, South Carolina. The building performance testing is done on full-scale 2- story models in a 21,000 square foot, 6 stories tall building. They can create a broad spectrum of weather – ranging from hurricane conditions, windstorms, wildfires, and hailstorms. They use the data to develop best practices in building construction.
The research center also has a “roof farm” which is an exterior installation to test decay and deterioration caused by severe weather. This allows them to conduct long-term evaluations of new materials and systems.
Recently, a contractor said to me that impact windows were a waste of money because they still can crack and the insurance will pay for any damage anyway. This is false logic. The IBHS research shows that a key mitigation step is protecting the windows and doors with either impact rated windows and doors, shutters, or plywood. When the openings are not protected, wind pressure can build up inside the house. Then, when a door or window is forced open, the roof blows off and the walls can collapse.
Their research also shows that roof cover damage is the most frequent source of hurricane-related insurance claims. Metal roofs tend to perform better than asphalt shingles but it is essential for the roofing material to be rated for high wind speeds. The roof assembly, deck, flashing, and the approved roof cover all must be installed to be the current building code.
Fortunately, here in South Carolina, we have stringent building codes. The IBHS rates the 18 hurricane-prone states on the quality of their building codes. Of the 18 states, South Carolina is third with a score of 92. Florida (95) and Virginia (94) are first and second, respectively.
Julie Rochman, the former IBHS CEO, said “ States with strong, updated codes saw stunning proof this year that updated, well-enforced building codes have led to the construction of homes and buildings that can stand up to fierce hurricane winds. It can’t be any clearer: these codes work.”
Material Science
As we work to make our buildings more sustainable, selecting environmentally responsible building products and materials is critical to reducing the carbon footprint and building healthy buildings. To select materials wisely, we have to understand what is in them, how they were made, and if they can be recycled at the end of their usefulness.
There are over 60,000 synthetic chemicals that were grandfathered when the first chemical regulatory system was adopted in the 1976 Toxic Substance Control Act. These materials are considered innocent until proven guilty and the burden is on the public to prove they are unsafe.
Toxic chemicals can be found in many things including paints, flooring, carpeting, PVC pipes, and appliances. One example is Methylene chloride that is found is the paint stripper Goof Off Pro Stripper. Veena Singla, Ph.D Associate Director of Science and Policy at the University of California, San Francisco said, “Methylene chloride is a toxic chemical that can quickly build up to dangerous levels in work spaces. It can cause rapid unconsciousness and death and has killed far too many people already. These tragedies are preventable.” The elimination of toxic materials is most important for interior products where occupant exposure is an issue.
Materials should also be evaluated on their life cycle which includes embodied energy consumed in the raw material extraction, production, transportation, use, and recycling or disposal. This is especially important for large quantities of materials.
A tool that help determine the best materials is an Environmental Product Declaration (EPD) which is sometimes described as a “nutrition label for products”. The EPD document outlines the sustainability of a product. It includes a list of the basic materials and components, a description of the manufacturing process, the life cycle assessment, the carbon footprint and other environmental impact data such as Volatile Organic Compounds (VOC) emissions or third party certifications.
There are two good resources to find sustainable healthy products. One is The Cradle to Cradle Products Innovation Institute is a non-profit organization that provides independent certification of sustainable products from building materials to cleaning supplies. Their list of certified products are found at www.c2ccertified.org. The other is Building Green found at www.buildinggreen.com
Home Security Systems
We decided that it was time to invest in a security system for our house and office after our house was broken into on Christmas Day. As we starting researching, we discovered that the options were almost overwhelming. Did we want to self-monitor the system or have a third party monitor? Did we need cameras? Should every door and window be connected to the system? How many motion detectors? What about smart-house options? Did we want a professionally installed system or do it ourselves?
Contemporary alarm systems are comprised of three basic sub-systems, burglar alarms, smoke and fire alarms, and carbon monoxide alarms. Temperature and water sensors are also available.
The burglar alarm monitors the perimeter of the house with door and window sensors and cameras; the interior is monitored with motion detectors. Select motion detectors that are pet sensitive and will not be set off by your animals. Most people opt for a combination of the above. Depending on the visibility of your house to your neighbors, second story window sensors may not be needed.
Smoke and fire alarms can be the basic smoke detectors or be upgraded with a heat detector which monitors a sudden rise in temperature. The building code requires a smoke and fire alarm to be located in each bedroom, outside of each bedroom, and on every level. The alarms must be interconnected (either wirelessly or hardwired) so that all the alarms will sound when one is activated.
Carbon monoxide is an odorless, colorless, poisonous gas. The carbon monoxide alarms are installed on each level of the house and detect when carbon monoxide is present at an unsafe level. The building code requires carbon monoxide alarms in houses with fueled fired appliances and/or houses with attached garages. Most systems offer a combination smoke, fire, and carbon monoxide alarm. This reduces the number of sensor mounted on the walls.
Temperature sensors monitor cold air inside the house to prevent pipe freezing. The water sensor detects water intrusion or a leaking water heater.
Cost can be a determining factor in deciding whether to have a centralized third party monitor or to self- monitor. A self-monitoring system will notify you on your smart phone when the alarm is activated. It is then your responsibility to call 911 or determine if it is a false alarm. One drawback with this system is if your phone is turned off you will not be notified. Centralized third party monitoring has an on-going subscription fee. Many home insurance policies provide a credit for monitored systems so it might be a break even investment. Both professionally installed systems and do-it-yourself systems offer centralized third party monitoring.
Remote access and the integration with a home automation system is available with most security systems. With the remote access you can log on and control your security system, thermostat, lights, locks, and other connected items. Some systems will even notify you when someone rings your doorbell and you can talk to them by video on your phone. Most systems allow you to add additional automation features at a later date.
Online reviews of security systems and meeting with local security specialists can help you determine the best solution for your needs and budget. The system we selected for our house and office was professionally installed and monitored. We chose it because of the ease of use, the ability to add home automation systems later, and the price was reasonable.
Hurricane Matthew at Edisto Beach
We are trained in the Safety Assessment Program (SAP). On Tuesday and Wednesday we were called to Edisto Beach to work with the South Carolina State Guard to assist the Edisto Beach Building Department in determining if houses were safe to access and occupy. The major issue on Edisto Beach was the large storm surge that dumped over 4 feet of sand on Palmetto Boulevard, which parallels the ocean. The front beach houses had at least 4 feet of sand under them.
Edisto Beach is an eclectic mix of old beach houses and newer contemporary houses. The difference between the houses that were built to contemporary codes and those that were not was obvious. In one older house, the post supporting the first floor was swept away. We were surprised that the house had not already collapsed. If this house was built to current codes – it would have driven piles instead of posts on a shallow foundation. In newer houses built on piles, garage space can be enclosed under the house with break-away wall. The break-away walls did what they were designed to do – break away, even in a case where a HVAC platform was attached to the break-away wall.
Many of the older houses had grandfathered living spaces in the flood plain, which is not allowed now for a good reason. The water and sand filled the spaces creating a huge mess that currently is filled with sand and soon will be filled with mold and mildew.
The wave action that brought in the sand, scoured under the parking slabs in the old houses. This left many of the slabs suspended in the air and very dangerous, especially since it was not evident that they were suspended from the street side. The newer houses had break-away slabs which broke and were washed about, sometimes taking stairs with them. A better practice would to use gravel in the parking area under the house.
It was also interesting to see the species of trees that blew down. Almost every Cedar tree we saw had blown over. Water Oaks were next followed by Pines. The Live Oaks that were down were usually hit by another tree first.
We also saw some areas that were hit by isolated tornados which is almost impossible to design for damage prevention. After spending time on Edisto Beach, it is understandable why the first responders want to make sure the area is safe before the residents return.
What is the 50% Rule?
Thoughts of hurricanes are starting early this year with the potential tropical storm forming off of our coast. In the past, I have written about protecting your existing house and best practices for new construction (March 2013 and December 2011, respectively). The area with some confusion are the rules for repairing and/or improving your existing house which I will address today.
Beaufort County and the municipalities within the county all participate in the National Flood Insurance Program (NFIP) that is administered by the Federal Emergency Management Agency (FEMA). FEMA establishes a base flood elevation above mean sea level which is revised periodically. Buildings must meet the NFIP requirements which include having the first floor above the base flood elevation or higher depending on the flood zone, along with other requirements.
If the cost of improvements or the cost to repair a damaged building exceed 50% of the market value of the building, the entire building must be brought into compliance with the NFIP requirements. The market value is for the building only, not the property, any landscape improvements, or detached accessory buildings. The value can be determined by a licensed appraiser or the county’s property assessment.
The only items that are excluded from the cost of improvements or repair are as follows:
- Plans and specifications
- Surveys
- Permit fees
- Cost to demolish storm damaged buildings
- Debris removal
- Landscape improvements
- Detached structures. If the detached structure is habitable space it is subject to the same rules when renovated or repaired.
Many existing houses in the county do not meet the NFIP requirements and must adhere to the 50% rule. Most houses built in accordance with the 2009 or 2012 edition of the International Residential Code (IRC) meet the NFIP requirements and are not subject to the 50% rule.
Municipalities often adopt a cumulative substantial improvement policy which combines any combination of repairs, reconstruction, rehabilitation, additions, or other improvements to a structure during a finite period of time that is limited to the 50% value. The cumulative substantial improvement policy for Beaufort County and Bluffton is 10 years; the City of Beaufort is 5 years; and Hilton Head currently does not have a cumulative substantial improvement policy.
When purchasing an existing house it is prudent to do the homework to determine if the house is built above the flood plain. A local surveyor can provide a flood elevation certificate that shows the flood zone, the required first floor elevation, and the actual first floor elevation. That fixer upper might seem like a good deal until you realize the cost of raising the first floor and meeting the NFIP requirements.
Winter proof your house
Brrrr…winter arrived this week and it seems even colder after the balmy Christmas and New Year. It is not too late to prepare your house for cold weather to keep warm and save energy. The most important thing is to keep the cold air out. A home energy audit is the best way to discover where your house is leaking. Typical leaky locations are electrical outlets, switch plates, door and window frames, attic hatches, dryer vents and plumbing, electrical, and cable connections in the exterior walls and floors. These leaks can be filled with caulk and/or insulation and the doors should be weather-stripped.
Your heating system should be maintained and the filters changed monthly for it to run at maximum efficiency. By turning the thermostat back 10 to 15% when you are away or out of the house you can save 10% on your energy bill according to the US Department of Energy. Only do this if you have a furnace. If you have a heat pump you should only set the thermostat back a few degrees. When a heat pump needs to heat a room quickly it uses the auxiliary electric strips which is very inefficient.
Curtains with insulated liners will help block drafts from leaky windows, especially in the historic homes with single pane glass. Be sure to open the curtains on south facing windows during the day to take advantage of the sun to warm the room.
There are several easy items to help keep you warmer. Reverse your ceiling fans to run clockwise to push the heat that has risen to the ceiling back down to the floor. This is particularly useful for rooms with high ceilings. Close the fireplace damper whenever there is not a fire burning. Glass doors on fireplaces help prevent the warm air in the room from going up the chimney. Move furniture away from the heating vents so the warm air is not trapped under or behind the furniture. Finally as your dad always told you, “If you are cold, put on a sweater”.