Last week during a discussion in an installation training class, it became obvious that too many installers and retailers aren’t being informed about Alternative Construction (AC) and On-Site Completion (SC) and what this means for the manufactured homes that they install and/or sell.
So, lets take a look and see if we can shed some light on these issues, starting with Alternative Construction.
When a manufacturer intends to produce a manufactured home with a construction aspect that does not meet the Manufactured Home Construction & Safety Standards (MHCSS), but will perform at least equal to the MHCSS, they can request HUD allow such construction.
Let me give an example:
Say you want the manufacturer to construct a home for your customer that has tankless water heaters instead of the typical storage type water heater. Since the MHCSS doesn’t provide for a tankless water heater, the manufacturer needs a special approval from HUD to omit the storage type water heater and replace it with the tankless type. That approval is called a Letter of Alternative Construction (or an AC letter).
Here is another example: your customer needs a shower that is designed for wheelchair access. The MHCSS requires a minimum 2” dam (or threshold) to keep the water from running onto the floor, making it impossible to access the shower with a wheelchair. The manufacturer can request an Alternative Construction authorization from HUD to provide a shower without a 2” dam, designed to facilitate wheelchairs.
In both of these cases, the home will not meet a specific requirement of the Manufactured Home Construction and Safety Standards, however they both will perform equal or better than the actual code requirement.
Currently, one of the biggest requests for AC letters is when a manufactured home is designed for the attachment of a site-built garage. There are many issues of code compliance that must be examined when designing a home for garage attachment. Issues such as the path of egress (exit) from the bedrooms, impact on lighting and ventilation in the area where the garage is attached, additional loads on the structure of the home, and electrical considerations, to name a few. But the omission of the exterior covering (siding) for the application of gypsum to provide the needed fire separation is where you will find the need for the AC letter. On a side note…the MHCSS still does not address carbon monoxide alarms! If you are selling/installing a home with a garage attachment, talk to the manufacturer about a combination smoke/CO alarm or an added electrical outlet where you can provide this important safety consideration.
Through the years, the most common use for an AC letter has been a home with a hinged roof, usually a 5/12 roof pitch or greater (this never made sense to me, but that is how they handled hinged roofs). Today most manufactured homes with a hinged roof are being constructed under the new On-Site Completion Process, which we will discuss in a our next post.
Here are a few “take aways” for retailers and installers when it comes to Alternative Construction.
- A manufactured home covered by an AC letter is determined to perform equal to or greater than the MHCSS requirements.
- Every manufactured home under an AC letter requires a notice to the perspective purchaser. This notice, as well as an appropriate checklist, and other information related to the AC process is provided by the manufacturer.
- You can identify a manufactured home constructed under a letter of Alternative Construction by the letters “AC” which will be included in the serial number.
- Often the home will require a special inspection.
- Both the retailer and installer should maintain records of compliance with the AC requirements, and a copy of any needed inspection of the completed home.
Ok…I hope this helps. If you have anything to add, submit a comment.
In our next post we will talk about On-Site Completion.