Casitas Foundations 101

Learn more about La Hacienda Casitas and our work in the RGV.

By Emily Axtman

Phase 1 of La Hacienda Casitas is underway! Site work has been going on for a few months now and the streets are beginning to take shape, as seen below. Up until now, the site progress has been horizontal: dirt has been moved around and wet/dry infrastructure has been installed. Although I've seen some pretty high mounds of dirt, nothing as vertical or as exciting as a house has started...until now!

Thus far, a total of 8 foundations have been poured. So what has been involved in this process?

Standing at the northwest street corner facing the building pad of the first 10 houses.

Standing at the northwest street corner facing the building pad of the first 10 houses.

Preparing the site:

In order to prep the site for the foundations, the Phase 1 area was first cleared 3', seen again in the photo above.

Foundation Prep

Preparing the pad:

(1) Due to soil instability in the Valley, 3' of select fill was required under each unit to ensure proper density and compaction ability. Select fill is used when native soils are not capable of adequately bearing the weight of the structure that will be built in that location.

(2) The select fill was then compacted in 6" deep increments, referred to as lifts. This process further ensures proper density and compaction.

(3) Once the fill was tested and the form-work constructed, a trencher was used to cut out the foundation lines. At this point, it looked like this:

Pani 2 copy

I know what you're thinking. This photo looks the same as the last picture! If you look more closely you'll notice the built-up select fill and the beginning of the form-work.

form work copy

Preparing the foundation:

The the select fill is piled high from the trenching while perimeters of the foundation are edged with form-work. After the form-work and trenching are complete, plumbing for the kitchen, bathroom, and utilities is roughed in. A plastic vapor barrier is then laid over the padding, tucked into the trenches and then stapled to the form-work. It is very important that the concrete be cast in a dry protected barrier and kept away from the soil. Continuous exposure to water and moisture can cause cracking in the concrete, leading to structural instability.

The rebar is assembled in stages onsite and set into the trenches first, then laid in a grid pattern on top of the padding. Because concrete has low tensile strength, reinforcement must be used that is high in tensile strength, such as steel rebar. Chairs, the dots in yellow above, are used to raise the rebar 2-3" above the padding. This ensures that the concrete will adhere to the rebar properly and surround it evenly. Once the rebar is inspected, it's time for the fun part... CONCRETE!

Concrete Proc

The concrete is spread evenly over the padding and into the trenches, then vibrated at the form-work edges to help the aggregate settle and release any air pockets.

Concrete is a composite material made up of an aggregate (such as stone), cement and water. When water is mixed with the dry aggregate and cement, a chemical process called hydration occurs, enabling the mixture to be molded and formed before hardening.

The timing and craft of pouring the foundation is key to the accuracy of the houses. Speaking to one of the foremen on-site, he said, "Pouring the foundations is the most stressful part of the process. Once we pour, it's final; so everything has to be right."

Concrete 2

Once the concrete has been distributed evenly, it's roughly smoothed using a screed. As the larger aggregate begins to settle, a bull float is used to smooth the top layer of the finer aggregate. To complete the process, edge and finish trowels are used to refine the concrete surfaces.

As I learned at 5:30am in the morning, pouring concrete is an early event. In order for the concrete to set, the air temperature can't be too hot or too cold. If the temperature is below 50 degrees, the hydration process slows down; if too hot, hydration occurs too fast, causing differential temperatures in the concrete that can lead to cracking, as well as compromising the final strength of the concrete. Due to the Valley's high temperatures, it's important to start as early as possible to beat the heat.

Prior to any foundation pours, a sample is taken from the concrete trucks and tested later to verify the strength and composition of the mixture. According to the tester, the foundations will cure enough in about 3 days to start framing. Fully cured concrete takes about 21 days.

A Designer's Paradise?

Learn more about La Hacienda and our work in the RGV.

By Emily Axtman

So what is bcWORKSHOP working on in the Valley besides La Hacienda Casitas?

The short answer: a lot.

To give some perspective about architecture practices in the Valley:

The city of Dallas, at a population of about 1.2 million, has 301 professional architecture practices according to the National Council of Architectural Registration Boards (NCARB) 2011 data. The city of Brownsville, at a population of 178,500, has 5 professional architecture practices.

Dallas averages 1 architecture firm for every 3,300 people. Brownsville averages 1 architect firm for every 35,600 people. So what's the big deal? Dallas has 10 times the capacity of people working towards providing better housing, public spaces and development within the city. Brownsville is in need of a greater design capacity and this is where bcWORKSHOP comes in.

Maggie Winter, a bcWORKSHOP designer, has been working toward implementing improvements for the quality of life in the LRGV since September 2011. Her projects have ranged from city-wide planning to housing and broader community development.

Justin Tirsun, a former VISTA at bcW, has been a part of the LRGV team since July 2012. Justin's main focus in the Valley has been policy research and development in the Colonias, as well as the Belden Trail. Among all of the projects, I have had the opportunity to work on the Alegria House.

Alegria House, front elevation.

Alegria House, front elevation.

bcWORKSHOP has been working with Ms. Alegria to design a new home for her and her 3 children. The Alegrias currently live in a mobile home without running water or electricity. Recently, Ms. Alegria's son was paralyzed in an accident, making accessibility part of their housing needs. Working within CDCB's Colonia Redevelopment Program, bcWORKSHOP has designed a home that will meet their needs and provide a healthy living environment. Construction is slated to begin in November!

The Colonia Redevelopment Program is a reconstruction & rehabilitation service for homeowners in Colonias currently living in homes that are not meeting their basic needs. Based on the sustainABLEhouse model,  bcW is teaming up with CDCB to offer a custom design service to the program. This opportunity directly involves the homeowners in the design and construction of their new home while remaining within the parameters of the Colonia Redevelopment Program. The bcW LRGV office is currently working with 4 families to design homes that will accommodate their needs, be energy efficient, and provide healthy living environments. We are thrilled to be working so closely with all of these families!

So now back to that OTHER housing project. What's going on with La Hacienda?! I'm excited to bring the news that the La Hacienda site has been under construction for 4 weeks now. With the infrastructural work underway (eg: water, sewer and fire lines; site-drainage and street layout) the first 8 homes will be under construction in the next couple weeks. The foundations have been staked and completion of these units is scheduled for mid-January. Stay tuned over these next few weeks: the houses are on their way!

La Hacienda site on 10/1/2012 facing east from Paloma Ln. 

La Hacienda site on 10/1/2012 facing east from Paloma Ln. 

La Hacienda Casitas

Learn more about La Hacienda Casitas and our work in the RGV.

By Emily Axtman

Founded on the need for safe, clean and affordable housing for families in the Lower Rio Grande Valley, the Community Development Corporation of Brownsville (CDCB) has been working with the residents of Cameron County since 1974. Their mission is to "assist low income families in attaining home ownership" and they've achieved this over the past five decades by providing more than 2,500 built homes. CDCB additionally provides home-buyer education and credit counseling, youth and job training, and colonia redevelopment, among other programs. They are the largest non-profit producer of single family affordable housing for home-ownership in the State of Texas.

bcWORKSHOP's Lower Rio Grande Valley (LRGV) team works alongside CDCB staff in their office in downtown Brownsville at 901 E. Levee Street. Current projects include:

  • Colonias Planning Project (Sept. 2011-present) - Grassroots efforts to build a planning framework and platform for rural communities to self-organize and address both localized and regional community development issues including insufficient infrastructure, home repairs, safety, and public health concerns.
  • Belden Trail (July 2012-present) - Community engagement and design for an urban 1-mile hike and bike trail that will run through West Brownsville.
  • Alegria House (August 2012-present) - Consultation and design of a small home that, in partnership with CDCB, will provide a family of 3 with a much needed fully-accessible house.
  • Self-Help and Colonia Home Design (July 2012-present) - Design services are now being offered for families that qualify with CDCB for a new home and who wish to participate in the design choices available for their new home.
  • Better Block Brownsville (May 2012-present) - A monthly Saturday event that demonstrates what a "better block" can be in Brownsville including bike/pedestrian-friendly streets, outdoor cafes and shade, local vendors and music.
  • La Hacienda Casitas (Feb. 2011-present) - The largest collaboration between CDCB and bcW to design CDCB's first multi-family housing development.
CDCB 's office in downtown  Brownsville

CDCB's office in downtown Brownsville

So how did La Hacienda Casitas get started?

I sat down with Mark Moseley, Manager of Special Programs and Initiatives at CDCB to ask him this question along with a few others. But first, let's get to know Mark!

La Hacienda Site Plan - The site design is focused on using a high-density housing model integrated with low-impact design. Covering just under 6 acres, the site design was informed by preserving as many existing trees as possible and centers around a long spine of central green space that provides community amenities including a meeting hall, barbeque pavilion and laundry facility. Through the integration of storm-water management (bio-swales and bio-retentions ponds) with native landscaping (native grasses, wildflowers and site-informed walking paths) a more cohesive and self-sustaining environment will be created for all residents and users.

Mark M

Mark Moseley, Manager of  Multifamily Programs, has over 20 years of experience working in the community development field. Prior to joining CDCBMark was the Executive Director of Tri-County HDC in HarrisburgPennsylvaniaMark has completed nearly $45 million in multi-family projects utilizing Low Income Housing Tax CreditsUSDA 514/516 (farmworker housing), HUD 202/811 (housing for the elderly and people with disabilities), Neighborhood Stabilization ProgramCDBG (Community Development Block Grant Program), Housing Trust Fund, and PA Homeownership ChoiceMark has overseen asset management for over $55 million worth of multi-family assets. Mark also served as the Senior Housing Developer for Rural Opportunities (PathStone) in HarrisburgPA and Housing Director with the Pélathé Indian Center in LawrenceKS.

Mark currently oversees CDCB’s REO (Real Estate Owned) projects and is leading CDCB’s newest venture into the multi-family rental market.

Emily Axtman: CDCB typically does single-family residences as individual projects. Why did CDCB choose to do their first multi-family housing project now and in Harlingen?

Mark MoselyWith the downfall of the single-family market, a multi-family housing project made sense financially for CDCB and also will provide more families with more housing in less amount of time and space.

La Hacienda  view south down "Center Street". The porches were designed to encourage more interaction among  La Hacienda  residents and xeroscaping will allow for low site-maintenance and require less water; both contributing to the project's focus on the importance of community and sustainability.

La Hacienda view south down "Center Street". The porches were designed to encourage more interaction among La Hacienda residents and xeroscaping will allow for low site-maintenance and require less water; both contributing to the project's focus on the importance of community and sustainability.

EA: Why did CDCB choose the property in Harlingen over other sites?

MMThe location was originally supposed to be on the outskirts of Cameron Park [one of the Cameron County colonias], however it was known that the site in Harlingen would receive one additional point on the tax credit application, [this was necessary in order to do the project] so CDCB went ahead with the Harlingen site. Securing the site in Harlingen essentially meant a better chance at receiving the tax credit and the project actually going through. CDCB will be leasing the land from the Cameron County Housing Authority for 75 years.

EA: How did bcWORKSHOP become involved and why?

MM: CDCB interviewed several architecture firms to take on CDCB's first multi-family housing project; most were qualified, however bcWORKSHOP stood out in that CDCB felt they shared the same philosophy and over-arching values.

EA: What has been the biggest challenge of the project so far?

[This is where Mark paused. I could tell he had a list...]

MM: Taxing laws, the platting process, it's been very political — the most political project I've worked on actually, working with architects...

And then Mark paused and asked, "Are you going to publish this?"  When I told him yes, he stopped his list at that.

Planning for La Hacienda has been a complex process since its inception. Many entities are involved — the CDC, funders, banks, designers, contractors — not to mention this is CDCB's first time taking on a project at this scale. After tying up loose ends over the past 2 months, the project has finally broken ground and is quickly moving along!


But La Hacienda isn't the ONLY project going on here in the Valley. I have been working with Maggie and Justin, the other team members of the LRGV crew, on several other exciting projects. Find out more about these projects in the next post!

The [Short] History

By Emily Axtman

HarlingenTX is located in the Lower Rio Grande Valley, which is comprised of 4 counties: StarrHidalgoWillacy and Cameron. Both Harlingen and Brownsville are in Cameron County.  Harlingen, 30 miles west of the Gulf of Mexico and 15 miles north of the US / Mexico border, enjoys warm (or hot in August) gulf breezes and plenty of tropical vegetation — my favorite being the Sabal palm tree.

Read More

Dallas to Brownsville

By Emily Axtman

My name is Emily Axtman and I've been a bcFELLOW for 8 months at bcWORKSHOP, Since November, I've been working on the La Hacienda Casitas project, a low income housing development in the Lower Rio Grande Valley (LRGV). I've been lucky enough to work on this project from schematic design through to the construction documents and am now following the project down to Harlingen (where the project is breaking ground in one week!) to be a part of the construction process first-hand.

Read More