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The Seven-Day House

A while back, in my post entitled Demolition Derby, I showed you some pictures of a house I'm working on in the Point Breeze section of Philadelphia. During demolition, we exposed some serious structural issues and, upon further investigation, have determined that the best way forward is to demolish most of the existing building and start new (actually, we're demolishing everything but the basement). Through discussions with the contractor, we determined that the best way to get the project built may be modular construction.

You've seen me write about prefab before, but this time I'm in from the beginning. The first step, now that we're building new, was to revisit the design drawings for the home to see what improvements could be made. When we thought we were going to renovate the existing house, we were limited by a number of factors--existing window placement and sizes, existing door placement, existing ceiling heights. However, if we are going to build new, we can do things the way we want to. The resulting design is more streamlined and efficient, and gives the clients more usable and high-quality space.

The next step was to visit the modular factory. The contractor has worked with Signature Building Systems before, so we started there. This trip combined two of my favorite things: building design and factory tours. The Signature factory is a huge open space--200' x 400' (that's 80,000 square feet, for those of you keeping track):

While at first the space looks chaotic, there's a very methodical process going on. The slideshow will give you the basic idea (sorry for any blurry photos--fortunately my architecture skills far surpass my photography skills!).

One of the things that struck me was the quality of the work going on. Historically, modular construction has had a bad reputation. But on my visit, I saw careful construction practices, quality materials, and skilled labor. Not only that, but the indoor construction means that everything is protected from the weather. Modular construction has also been shown to reduce overall construction-related carbon emissions, since the builders tend to live relatively close to the factory, thereby reducing the number of miles driven each day. Plus, large material orders can be placed and delivered in bulk, reducing shipping costs and impacts.

Once the modules are delivered to the site, a crane lifts them into place. Signature has a team that will fasten them to the foundation and to each other. Then the local contractors will close the seams inside and join the plumbing and electrical systems. They are also responsible for the exterior finishes (in this case, stucco and brick).

Obviously, I'm pretty excited about this process. It's not perfect for every situation, but it holds a lot of promise for the future. I'll keep you posted as we move forward.

Anyone out there have any experience with modular construction?

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AIA Suburban Pro Con Follow Up

This past Friday I had the pleasure of making a presentation about the Prefab on the Main Line project at the AIA Suburban Pro Con in East Norriton, PA.  It was a joint effort, along with homeowner and Pete Maruca of Orion GC, the general contractor for the project.  Actually, the homeowner did most of the work, with Pete and I chiming in and filling in details as she went.  It was a great experience, and thank you to everyone who came out.  An extra thanks goes out to the people who asked such great questions at the end, and to Pat Gourley at AIA Philadelphia for putting it all together.

Our presentation was an overview of building a prefab residential project.  Specific points we covered were:

  1. What sort of client is looking for a prefab project?
  2. What situation lends itself to prefab?
  3. What are the possibilities, limitations, and benefits?
  4. Who are the team members?
  5. What are the basic steps in the process?

We used our project as a case study.

1. What sort of client is looking for a prefab project?

In our project's case, the client actually led the prefab idea.  The clients were well-educated about the process and saw it as a way to build affordably given a situation they hadn't expected facing.  This affordability sometimes comes from a reduced construction cost (I'll talk about this more later), but more reliably comes from a reduction in construction time.  This reduces the amount of time that the homeowner must cover the mortgages, taxes, and upkeep for both their current and new properties.  There are many times when the idea of prefab won't even be on the client's radar; in this case it is the contractor or architect's turn to introduce it if it's appropriate.

2. What situation lends itself to prefab?

The client's situation also drove the prefab decision.  They are a three-generation family who wanted good schools within easy reach of Philadelphia.  Both parents work in the city, and the grandmother takes care of the children during the day.  Houses in the clients' chosen school district are large, but most were either too expensive or needed too much renovation to make them work.  They did, in fact, find an existing house that met many of their needs.  However, some extenuating circumstances led to the desire to do a more extensive remodel where incorporating modular construction made more sense, for several reasons.

The factory-built modules would be of very high quality, meaning that the new structure would be just as solidly built as its neighbors.  And the reduced on-site build time meant less noise and traffic pollution for everyone, including the nearby elementary school.  In fact, the main bulk of the house was erected in just six days.  Finally, by starting with a pre-designed floor plan, the clients could save time and money on design.

Inside the factory

Inside the factory

3. What are the possibilities, limitations, and benefits?

Many people think of prefab as just Dwell-magazine modern.  However, there is no limitation to the possible styles.  In this case, the clients wanted (and got) a Tudor-style home.  You can visit the websites of many manufacturers to see what they offer, and remember that many of them will do custom work.

You can do more than just modern. From prefabs.com.

As far as floor plans go, the sky's the limit.  This home was closely based on a stock plan from the manufacturer, but small tweaks were made.  In particular, this house needed to connect to the remaining portion of the previous house--a small stone building that was likely the first home on this property--via a breezeway from the breakfast nook.  The main limitation is the size of the modular boxes.  They are limited, of course, by the highway.  The largest units are typically 16' x 45'.

In the existing house, the old stone building was buried within many additions.

Now, the original stone portion is exposed and is connected to the new prefab home by a site-built breezeway.

The benefits of prefab are numerous.  The majority of the building is constructed under climate-controlled factory conditions.  This means that the interior is never exposed to rain, a source of squeaks and, sometimes, mold.  The modules are very sturdy, since they have to survive a road trip.  Because the whole thing is built inside, there are no work delays due to weather.

From a green standpoint, the number of worker miles driven is greatly reduced over the course of the project.  Factories also tend to be built where they have easy access to materials, so large quantities can be delivered to the factory over shorter distances, thereby reducing those miles.  Module sizes are optimized to reduce cutoff waste, and scraps are saved and used as needed on future projects.

The cost savings for prefab are hotly debated.  Some claim that a stock plan modular house will cost 10%-15% less than its site-built comparison.  Others say it actually costs more, given the inevitable upgrades, tweaks, and additions.  However, when it comes to schedule there is no comparison.  The ability to construct the modules concurrently with the demolition, site preparation, and foundation construction greatly reduces the overall project schedule.  The optimized, assembly-line style factory process is also a contributing factor to time savings.

4. Who are the team members?

For this project, the main team members were the modular company (Simplex), the homeowners, the local general contractor (Orion GC), the site engineer, the structural engineer, and the architect (me, of course).  

The modular company provided the initial house design and its foundation requirements.  They were responsible for specifying all the materials to be used in the house, and of course for manufacturing it.  They delivered the "boxes" and set them in place.

Setting the fifth module of the main house.

It was the site engineer who first alerted the client to the idea of marrying a portion of the existing building with the new, which made the site requirements much easier to deal with.  This engineer also helped manage much of the permitting process with the Township.

My initial role was to help determine which parts of the existing house could be saved and how they could be integrated into the new house, which was based on a pre-designed prefab floor plan.  As the project progressed, I became more involved in tweaking the prefab design to meet the clients' needs.  I also designed the links between the old and new portions and between the house and the garage, and documented the basement and foundations.  The structural engineer assisted as needed.

Stone house and breezeway concept views.

Construction drawings for the stone building and breezeway.

The general contractor did demolition, site preparation, and foundation work before the modules arrived.  After they were set and connected (by the manufacturer's crew), the GC did the exterior finish work and completed the interiors.

Existing house demolished, stone house exposed, and foundation poured. Ready for prefab unit delivery.The prefab units arrive on site.The modules are set into place and connected.The Client and Orion GC's Foreman Irv Morey standing inside newly-set units. In the doorway, the joint between the units is clearly visible. Notice, also, that the unit arrived with finished trim and paint.

Last, but certainly not least, is an active, engaged homeowner.  But isn't this important for every project?  We were lucky in this respect--being active and engaged seemed to come naturally to these clients.

5. What are the basic steps in the process?

  1. Identify a site, and determine whether modular is the right decision for either an addition or new construction,
  2. Select a layout to start with, customizing where necessary,
  3. Kickoff manufacturing / Prepare the site and foundation,
  4. Deliver the “boxes”,
  5. Complete the finishes (interior & exterior), HVAC, final plumbing, etc.,
  6. Move in (in our case, 3 months after box delivery).

I could go on and on about this project, but these are the basics.  Contact me if you have other questions; I'm happy to talk more!  In the meantime, here are some more photos:

Rear of house.Front of house just after modules were set. It took six days to set all of the modules.The finished product. From the time the modules were set (previous photo), the house took three months to complete.

Interior view of the stone house.

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Prefab Progress

Well, I was out for the first "set day" on the Main Line Prefab project I wrote about in the last post.  It was a fun day.  The units arrived on Sunday, and were scattered around the project site.  There were also a few units parked around the corner.  I arrived at 9:10 am, and the first box had already been placed.  By 9:30, the second one went down.  The crew worked very quickly, attaching cables to the box, raising it and then lowering it into place, removing the cables, and securing the box to the foundations and to its neighbors.  I stuck around until about noon, and by that time five boxes were in place.

 Cheryl Allison, a reporter from the Main Line Times, attended; you can read her article and see the paper's photos and video here.  The video features Pete Maruca of Orion General Contractors.

Below is a gallery of my own photos.

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Prefab on the Main Line

Recently, I had the opportunity to work on a residential project that involved a high-end modular home on the Main Line (Montgomery County, PA).  The project site was a 1.2-acre parcel containing an existing house and three outbuildings.  When the homeowners contacted me, they had already nearly completed the design of the prefab house.  The plan was to demolish all the existing buildings and replace them with the new one.  However, they had run into an issue with the local stormwater regulations, and needed some help.  

After reviewing the regulations and consulting with Rob Lambert of SITE Engineering Concepts (the project's Civil Engineer), we found that keeping part of the existing structure would help us avoid the most onerous parts of the law, while still allowing us to be good environmental stewards.  My part of the project, then, was to work on rehabbing the existing portion we planned to keep and to develop a connection between it and the new house.

I visited the existing house and was immediately intrigued.  The building had been added on to over the years, starting with a mysterious one-room stone building.  This was the part that really caught my interest.  We decided to keep the stone portion and create a breezeway connection between it and the main house.  As the project developed, I worked on other areas, including a basement and foundation plan for the new house, the connection between the house and the prefab garage, and general design review and coordination.  All in all, a very interesting project with great clients.

If you're interested, you're welcome to visit the project site on January 11th & 12th to watch the prefab modules being delivered and installed.  See the press release for more details on where and when the event will take place, or visit the project's Facebook page.  You can also see images of the project below.

p.s. I'd be remiss if I didn't mention

Orion General Contractors, who is responsible for on-site work, and Simplex Homes, builder of the modular units.

Some views of the project:

Site Plan: Existing stone building shown red, Breezeway shown blue, Prefab house shown yellow, Existing outbuildings to be demolished shown gray, Existing house to be demolished shown dashed.

The existing stone building with the rest of the existing house stripped away.

The restored stone building with new breezeway.


The restored stone building with new breezeway.

Restored stone building with breezeway and prefab house in background.


Restored stone building with breezeway and prefab house in background.

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