The shipping container trend has arrived in Colorado. The time is right to start using the tremendous oversupply from importing foreign goods. (Ironically, at the time of this article, a dockworker union strike has resulted in thousands of shipping containers stranded on ships off the coast of California and threatens the East Coast trade.) The piles, literally walls, of shipping containers are transforming Los Angeles docks and neighborhoods. They are attracting undesirable activities, vermin and have become quite a nuisance. So the question is, “How can we solve the senior housing crisis while benefiting the environment?” Shipping container homes!
Architects across the country and around the world are coming up with ways to create inexpensive housing alternatives for seniors (and others like the millennials) who don’t want a large living space or the cost. Relevant designs have resulted in award winning homes. Areas with low cost land are experiencing new levels of interest as more seniors are “thinking outside the box” and researching previously overlooked towns.
What Are Seniors Looking For In Housing?
- Cost. This isn’t a deal breaker for some seniors who drift towards Active Adult communities starting in the 400’s. But for a majority of Americans who are counting dollars and/or on a fixed income, an inexpensive community is attractive.
- Size. Many seniors are downsizing at this stage in their lives, due to empty-nest or other changes in lifestyle.
- Community. Being part of a community is key to a healthy balance. Seniors have more time to give to the community and benefit the most from the support. A diverse community, serving all age groups, is vibrant and attractive.
- Health Services. Seniors enjoy being close to basic health services, such as doctor, dentist and hospital facilities. Many are members of health clubs, as staying active is key to longevity.
- Culture and Entertainment. Dining out, seeing a play, attending a concert, joining clubs and frequenting events are all ways seniors can stay social and engaged.
- Climate. Most seniors are excited to be outdoors, enjoying nature. Gardening is a trend for retirees as well. A nice climate, that allows outdoor activities much of the year, with a decent growing season, is very attractive to seniors.
- Transportation. Although still a challenge to get on a bus or train and be shuttled to your favorite venue in Colorado, the easy access to airports is a plus.
Colorado – Your Next Home Town
Colorado towns offer most of these things, as evidenced by the steady increase in population. The climate boasts 362 sunny days a year. The average temperatures are between 30-75 degrees. Due to the high cost of housing in the urban centers, many rural areas are seeing an influx of fixed income seniors. Infill city lots that have infrastructure in place, are being redeveloped into senior subdivisions. Small senior houses fit into this type of development due to their proximity to amenities and easy emergency access.
Shipping container homes are a method of saving our precious natural resources by using a structurally-sound material that the United States has in abundance. It’s a way to reuse an already manufactured module and turn it into a “dream home.” The average construction cost of a 2000 square foot “stick-built” house in Colorado is averaging $130/ square foot in the Denver Metro area (www.trulia.com). A used 40’ x 8’x 8.5’ steel shipping container is $2,000-$4,000. The steel container provides a strong, cheep building material that can be redesigned and stacked. Designed in Denmark
The area can be readily modified and connected for efficient use of space. Most of the time, the exterior will be cocooned with insulation and some sort of exterior finish, like Hardie Plank. The interior walls are simply the steel container, giving the home a modern, “industrial chic” appearance which is a popular design. Other non-combustible materials may be used on the exterior, allowing the house to be utilized in wildfire interface areas. Simple interior finishes can keep the cost down significantly. Some builders will reuse features of the container itself to accentuate the unique design. In some cases, shipping containers come with wood floors already installed. In the design represented below, passive solar features have been incorporated into the home, using solar panels on the roof, in addition to tapping the sun’s power through the angles of the windows and roofline. Constructing the home on pedestals or peers allows utilization of land within a floodplain or otherwise constrained due to natural features, after certain modifications.
Many “kits” or “prefab” buildings are available on the internet. The unlimited configuration of the container can be designed to suit all senior needs. Putting the homes on trailers can allow mobility if the occasion arises, allowing more flexibility for those seniors who prefer to be “snow birds.” As housing and basic material prices continue to rise, finding adequate senior housing becomes more difficult, which makes shipping container construction worthy of consideration.
Tella Firma: a Cost-Effective Alternative to ‘Floating Slabs’
John Clarke, P.E. President at RMG Engineers
Floating Slabs: don’t just you love that name? Let’s design floors that “float”. It just doesn’t sound right, especially for a structural engineer. But, we all know that when you place a floor directly on our sensitive Colorado soil, it is going to move. So we create what we call a floating system. Since it is cheaper to use a slab-on-grade for a commercial floor, we design for the anticipated movement. The lower level walls are hung from the framing above, leaving a gap along the bottom to allow the slab to move without distressing the wall (or set the wall on the slab with the gap at the top). This void system can get complicated in addition to the plumbing and mechanical systems which must be sleeved or made flexible for the slab to move. Storefront doors also need to be installed in such a way to be isolated from the slab to avoid the constant scape at the bottom. And, by the way, the floor is still going to move so be aware of tile or other rigid type floor toppings.
Okay, so how expensive can the options be? A structural floor that spans over the soil is typically the alternative. But, just the name sounds expensive! Typically a wood framed floor is used consisting of floor joists and beams. This requires a crawlspace for the 18” clearance above the soil, per code. The framing and crawlspace requires a raised floor level or a deeper excavation. This space must also be ventilated to control mold issues. You can use steel joists to cut down on the clearance, but now you are escalating the cost of the structural material.
A structural concrete floor can significantly reduce this depth, since the only clearance needed is a gap to allow for soil heave. But, conventionally reinforced concrete slabs are limited in their span lengths requiring additional supporting beams and pier supports. These supports are in addition to the foundation pier system. The slabs must also be supported by formwork during the pour and curing process, which can be expensive.
This brings us to a proven alternative system that was introduced to Colorado last year: Tella Firma. This is a structural slab system that is poured directly on the ground and then lifted into place, avoiding the costly formwork. The slab also utilizes proven post-tensioning systems that span directly between isolated piers without the use of costly deep beams. Piers are laid out in a grid fashion under the entire footprint, typically eliminating 20% of the piers of a conventional pier and grade beam system. Structurally rated lifting mechanisms are placed at each pier. Post tension cables are laid out in both directions. The slab is poured, typically 5” thick. After a 3 day cure, the cables are pulled and the slab is raised by the embedded lifting mechanisms 6” to 10”, depending on the soil swell potential. The building is them constructed directly on the structural slab.
The advantages of this system include:
- Elimination of the crawlspace
- A shallower floor thickness
- A reduction in the number of piers
- Future adjustability of the floor
- And, the end of the “floating slab”!
This system provides a main level commercial floor that will not move due to supporting soil heave. Storefront doors scraping on floating slab floors are no longer an issue. The cost of this system is cheaper than conventional pier and grade beam systems and most over-excavation schemes. Colorado Foundation Solutions (CFS) is the sole provider of the lifting mechanisms for this patented floor/foundation system in Colorado. The slab can be installed by any adequately trained crew. The design can be provided by any structural engineer familiar two-way flat slab post-tensioning systems. RMG Engineers is the only Colorado engineer designing these systems to date. Contact either of these firms for more information on this Tella Firma system that eliminates floor slab movement.
Senior living and housing design as my grandparents and parents knew-it has changed dramatically and must continue to adapt and grow to be successful. With more than 10,000 baby boomers turning 65 every day and an estimated 5-8% of the population opting for some form of senior housing the demand will continue to grow. As I deal with aging parents in that demographic and talk to them about their needs and desires for their future living arrangements. I found that their desires and concerns echo a lot of the same desires and concerns that I see being utilized within today’s successful senior developments.
First and foremost they wish to remain in the family house as long as possible. Over the past 10 years they have adopted their existing 1950’s, 2 story home to accommodate single level living. This is not always feasible and affordable to do. For example, they remodeled the kitchen, living and laundry rooms to accommodate their senior years, but their bath room could not feasibly accommodate wheel chair accessibility. Some senior housing developments provide “At-home” services so that ind viduals can remain in their homes longer. These service providers have the in-house services and are finding that they can expand to accommodate seniors with in their own environments.
The new designs must be flexible and customizable. These seniors are coming from a time where they have had many options and choices to select from in their current built environments. These options are not limited to the physical spaces but, also include psychological conditions and life styles from independent living to memory and health care services. The successful development will offer a diversity of service that can accommodate these new discriminating seniors. The old cookie cutter retirement home is obsolete. Today’s seniors will want their spaces to have their own identity. Having access to amenities such as workshops, exercise, yoga and craft rooms, will be an important part of extended living lifestyle.
Today’s seniors are more active and social than past generations; they want to be a part of a larger community and not left out on the “island”. The newer developments are being built closer to the urban centers and are being integrated with in these communities. The majority of these seniors are looking to maintain a healthy and vibrant lifestyle and being active not only within their housing community, but the larger community as well. The new developments will promote social gathering and sharing of amenities.
The new design will need to provide unique or distinctive amenities in order to stand above the competition. Today’s seniors want a connection to the outdoors, natural features are a big plus, therefore the site location itself can be a unique amenity. A good development will offer a range of green spaces, walking and biking trails, community gardens and other outdoor activities. These seniors are environmentally conscience and would like for their built environment to utilize sustainable building materials and minimize energy impacts. Incorporate light and airy exercise and communal spaces that are inviting and promote heathy activities and socialization.
Today’s seniors are very much engaged in technology and “plugged in”. Not only will technology be a big part of the social fabric of the community but will be utilized for health and wellness, connection to family and health care professionals and security monitoring as well. The leading edge developments will incorporate tech centers for its residence to access.
Today’s senior developments will provide an abundance of health and wellness care facilities. These care programs will need to be available but as discrete as feasible. The new developments can incorporate every facet of continuing care, from senior housing, independent living, short-term rehabilitation and memory care, along with the more traditional, assisted living and hospice care or services. These services can be bundled or a la cart, but will provide today’s seniors with an expectation of what their retirement dollars can provide.
The successful development will overcome the negativity of the traditional “nursing home”. The new design philosophy should embrace a departure from the stark institutional nursing home and make the residence feel at home. Spaces can be tailored for individual taste, and to accommodate the residence physical and mental status, while allowing for future reassessments. The development that can provide its future residence the best options will be more desirable to today’s active seniors.
Mongolia Update From John Clarke, P.E.
There are serious discussions with the City of Ulan Bator (or Ulaanbaatar) and our (RMG and 84 Lumber) representatives in Mongolia for a 1000-home development to replace a portion of their Ger districts. Ulan Bator is the capital city of Mongolia with a population of 1.34M. This population includes approximately 700,000 people living around perimeter of the city in what is called Ger Districts. These are areas where people from throughout the country came to the city looking for work when the government was converted to a democracy with a capitalist economy, after years of living within the sphere of the Soviet Union. These people were all given land as the socialist system was changed to private ownership. The problem is there was no infrastructure built for all these people. They all live in their gers (yurts) or wooden shacks with no water, electricity, heat or sewage systems. Is has become quite an issue and the government is looking for ways to house these people. Besides building high rises, they are looking at lower density options that would better fit their nomadic culture and the vast open space that is available. This has been one of the goals of 84 Lumber and RMG: to provide housing developments based on typical U.S. housing construction methods and subdivision layout design.
The City recently indicated they would like to use this system from the U.S. with 84 Lumber as part of the re-development of these areas. This came after the “Builder Blitz” we completed in June, where three houses were constructed (foundations already in place) in 3 days. Negotiations are beginning now.
Stable Floors without the Hassle Published in the Colorado Real Estate Journal
Multifamily developments can range from simple single-story duplex buildings to several stories of numerous units. They may be constructed of wood, steel or concrete. The ownership may be retained by the original developer or the units sold to individual buyers. Some projects may have common areas for the use by the tenant/owners or consist of simple living units with minimal common amenities.
One thing all these buildings have in common is a main level floor!! OK, that may not be worthy of the drum roll you were hearing as I was leading up to this subject. Floors are certainly not that exciting. Well, they shouldn’t be anyway. How can someone get excited about their main level floor? It is something you walk on. You expect it to be level and it should remain dry. You don’t want it to squeak. The clinking of the glass in the dining room cabinet when you walk on a bouncy floor can be annoying. A floor should be out of sight and out of mind.
So, how do designers make sure floors are seen and not heard? As most developers and managers of multifamily projects along the Front Range know, our soil here is not too friendly. Mainly, it consists of clay that tends to expand when it gets wet and shrink when it dries. These conditions can play havoc on main level floor systems placed directly on the soil, such as slabs-on-grade. As the soil moves, so does the slab, and everything on it. This is not good when you have just installed an expensive tile surface to make the units more attractive to potential buyers. Cracks are not attractive! These types of floors may be acceptable in a basement, but most multi-family structures do not include basement levels. What is a designer to do?
One approach is to remove these unstable soils to a particular depth. The area is then replaced with a more stable soil and compacted back into place. The slab is then poured directly on this new material. Although the condition is improved, this approach still does stop movement of the floor.
There are ways to strengthen these slabs-on-grade to resist the dreaded cracking and offset the uplift pressures of the soil. The most cost-effective method of strengthening the slab is to use post-tensioned cables, which pre-compress the concrete to control cracking. The slab becomes stiff enough for when the soil wants to lift the slab (it has to lift most of the building, which usually is enough weight to offset the lifting pressures). But, these systems are only good for certain expansive soils and are less effective for smaller building footprints.
Another commonly used system is a structural floor set off the ground. This system eliminates the interaction of the unstable soil from the floor. Often these floors consist of wood framing. But, wood must be kept a minimum distance away from the soil to avoid deterioration. The resulting crawlspace must then be ventilated to control the growth of mold in these enclosed areas. Not a pretty sight! Steel floor framing is an option, but the floor sheathing still is typically wood. What is needed is a stable floor material that will not rot.
This brings us back to concrete. (Remember, it is not “cement”! That’s the powdered stuff in the concrete). But, the issue with these floors is they require expensive forming systems to support the wet concrete until it cures. This brings us to a new floor system that does deserve a drum roll!
Tella Firma™ is a patented system that provides a stable floor for multifamily structures. This system eliminates floor movement due to direct interaction with Colorado’s unstable soils. Your floor will be seen, but not heard from again!
What is Tella Firma™? First, a grid of piers is installed across the footprint. Then, Tella Firma™ lifting mechanisms are placed at each support. A slab with tensioning cables is poured directly on the ground, and the cables are pulled like any other post-tensioned slab system. Then the magic begins! The threaded rods of the lifting mechanisms are turned from above, lifting the slab off the soil to create a void space of typically 4” to 8”. This void separates your floor from the harmful effects of the unstable soil. The slab is supported by the grid of piers. The structure is then built directly on top of this structurally suspended slab.
This system has been used in Texas, where they have similar expansive-type soil, in more than 800 structures. Four such systems have been built in Colorado in the last year, with more being planned. With the concerns over annoying lawsuits in the multifamily industry, a stable floor system helps eliminate one possible area of contention. These systems are cost-competitive compared to other systems that attempt to provide similar stable floors. Plus, the lifting mechanisms, which remain embedded in the slab floors, allows for future adjustability of the foundation if ever needed!
Discover the peace of mind of knowing your floor system will not bother you again!
As a guest on the Denver Real Estate Radio Show, Keith Moore, Colorado licensed architect at RMG Engineers, discusses the differences between a House Designer or Planner, and an architect. An architect knows exactly how to take your visions and ideas and make them a reality by making sure they can be structurally supported. RMG Engineers is your go-to firm because not only can we help with your home’s design, but we creatively and practically find engineered solutions to literally support the design. Watch the radio segment to learn more.
Nate Dowden, Geotechnical Engineer at RMG Engineers, was featured on Denver Real Estate Radio show and discusses why it is important for a homebuyer to be concerned about the type of soil a house was built upon. We have a variety of soil types along the Front Range, ranging from sand to claystone. The term expansive soil is used frequently when referring to Colorado soil, and these are the soils that when they are wetted, swell up. It is important for buyers to looks at the drainage around the house, and make sure that water runs away from the foundation system. RMG Engineers can provide soils tests for anyone looking to buy a home or purchase a lot in Colorado.
Every year, the Colorado Springs Business Journal (CSBJ) recognizes businesses in various industies. RMG Engineers was named 2nd in the Best of Engineering Firms category. Read the list of recognized businesses here.
Mark Weidhaas’s article in the Colorado Real Estate Journal (CREJ) titled Structural Engineering Needs: Industrial Plant addresses the question, “When is it necessary to call and consult with a professional structural engineer?” Click here to read the full article by Mark Weidhaas